Talwin

Mixed Opiate Agonist-Antagonist

May be administered by intravenous, intramuscular, or subcutaneous injection. However, the subcutaneous route should be used only when necessary, due to possible severe damage at injection sites.
No dilution is necessary.
Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit.

seizures / Delayed / Incidence not known
increased intracranial pressure / Early / Incidence not known
toxic epidermal necrolysis / Delayed / Incidence not known
angioedema / Rapid / Incidence not known
Stevens-Johnson syndrome / Delayed / Incidence not known
erythema multiforme / Delayed / Incidence not known
anaphylactic shock / Rapid / Incidence not known
apnea / Delayed / Incidence not known
neonatal opioid withdrawal syndrome / Delayed / Incidence not known
serotonin syndrome / Delayed / Incidence not known
SIADH / Delayed / Incidence not known

tolerance / Delayed / 1.0-10.0
euphoria / Early / Incidence not known
confusion / Early / Incidence not known
depression / Delayed / Incidence not known
dysphoria / Early / Incidence not known
hallucinations / Early / Incidence not known
respiratory depression / Rapid / Incidence not known
dyspnea / Early / Incidence not known
constipation / Delayed / Incidence not known
hypertension / Early / Incidence not known
sinus tachycardia / Rapid / Incidence not known
hypotension / Rapid / Incidence not known
skin ulcer / Delayed / Incidence not known
eosinophilia / Delayed / Incidence not known
leukopenia / Delayed / Incidence not known
neutropenia / Delayed / Incidence not known
nystagmus / Delayed / Incidence not known
blurred vision / Early / Incidence not known
urinary retention / Early / Incidence not known
uterine contractions / Early / Incidence not known
psychological dependence / Delayed / Incidence not known
physiological dependence / Delayed / Incidence not known
withdrawal / Early / Incidence not known
infertility / Delayed / Incidence not known
impotence (erectile dysfunction) / Delayed / Incidence not known
hyponatremia / Delayed / Incidence not known
adrenocortical insufficiency / Delayed / Incidence not known
hyperalgesia / Delayed / Incidence not known

nausea / Early / 1.0-10.0
vomiting / Early / 1.0-10.0
irritability / Delayed / Incidence not known
dizziness / Early / Incidence not known
headache / Early / Incidence not known
tremor / Early / Incidence not known
drowsiness / Early / Incidence not known
insomnia / Early / Incidence not known
weakness / Early / Incidence not known
paresthesias / Delayed / Incidence not known
tinnitus / Delayed / Incidence not known
anorexia / Delayed / Incidence not known
xerostomia / Early / Incidence not known
dysgeusia / Early / Incidence not known
diarrhea / Early / Incidence not known
abdominal pain / Early / Incidence not known
syncope / Early / Incidence not known
flushing / Rapid / Incidence not known
pruritus / Rapid / Incidence not known
urticaria / Rapid / Incidence not known
scleral induration / Delayed / Incidence not known
rash / Early / Incidence not known
injection site reaction / Rapid / Incidence not known
miosis / Early / Incidence not known
diplopia / Early / Incidence not known
hyperhidrosis / Delayed / Incidence not known
chills / Rapid / Incidence not known
libido decrease / Delayed / Incidence not known
gonadal suppression / Delayed / Incidence not known
amenorrhea / Delayed / Incidence not known

Opioid use requires an experienced clinician who is knowledgeable about the use of opioids and how to mitigate the associated risks. Opioids expose users to the risks of addiction, abuse, and misuse, which can occur at any dosage or duration. Although the risk of addiction in any individual is unknown, it can occur in persons appropriately prescribed an opioid. Addiction can occur at recommended dosages and if the drug is misused or abused. Assess each individual's risk for opioid addiction, abuse, or misuse before prescribing an opioid, and monitor for the development of these behaviors or conditions. Risks are increased in persons with a personal or family history of substance abuse (including alcoholism) or mental illness (e.g., major depression). The potential for these risks should not prevent the proper management of pain in any given individual. Persons at increased risk may be prescribed opioids but use in such persons necessitates intensive counseling about the risks and proper use of the opioid along with intensive monitoring for signs of addiction, abuse, and misuse. Abuse and addiction are separate and distinct from physical dependence and tolerance; persons with addiction may not exhibit tolerance and symptoms of physical dependence. Opioids are sought by drug abusers and persons with addiction disorders and are subject to criminal diversion. Abuse of opioids has the potential for overdose or poisoning and death. Consider these risks when prescribing or dispensing opioids. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity. Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of an opioid for persons in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. Do not use immediate-release opioids for an extended period unless the pain remains severe enough to require an opioid and for which alternative treatment options continue to be inadequate. Many acute pain conditions (e.g., pain occurring with surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid. Clinical guidelines on opioid prescribing for some acute pain conditions are available.[30219]

Pentazocine is contraindicated for use in patients with significant respiratory depression and in patients with acute or severe asthma (i.e., status asthmaticus) in unmonitored care settings or in the absence of resuscitative equipment. Receipt of moderate doses in these patients may significantly decrease pulmonary ventilation.[30219] Additionally, avoid coadministration with other CNS depressants when possible, as this significantly increases the risk for profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate; if concurrent use is necessary, use the lowest effective dosages and minimum treatment durations needed. Monitor patients closely for signs or symptoms of respiratory depression and sedation.[61143] In patients with chronic obstructive pulmonary disease (COPD), cor pulmonale, decreased respiratory reserve, emphysema, hypoxia, hypercapnia, respiratory insufficiency, upper airway obstruction, or preexisting respiratory depression, it is recommended that non-opioid analgesics be considered as alternatives to pentazocine, as even usual therapeutic doses of pentazocine may decrease respiratory drive and cause apnea in these patient populations. Extreme caution should also be used in patients with chronic asthma, kyphoscoliosis (a type of scoliosis), hypoxemia, or paralysis of the phrenic nerve. Patients with advanced age, debilitation, or sleep apnea are at an increased risk for the development of respiratory depression associated with pentazocine. Use with caution in patients with obesity as this is a risk factor for obstructive sleep-apnea syndrome and/or decreased respiratory reserve. Opioids increase the risk of central sleep apnea (CSA) and sleep-related hypoxemia in a dose-dependent fashion. Consider decreasing the opioid dosage in patients with CSA. Pentazocine should not be used during impaired consciousness or coma, as significant decreases in respiratory drive may lead to adverse intracranial effects from carbon dioxide retention. Respiratory depression, if left untreated, may cause respiratory arrest and death. Symptoms of respiratory depression include a reduced urge to breathe, a decreased respiratory rate, or deep breaths separated by long pauses (a "sighing" breathing pattern). Carbon dioxide retention from respiratory depression may also worsen opioid sedating effects. Management of respiratory depression should include observation, necessary supportive measures, and opioid antagonist use when indicated.[30219]

Available data with pentazocine use during human pregnancy are insufficient to inform a drug-associated risk for major birth defects and miscarriage. Based on animal data, advise pregnant women of the potential risk to a fetus. Neural tube defects, including exencephaly and cranioschisis, were observed when a single dose of pentazocine at 4.4 times the human maximum daily dose (MDD) of 360 mg based on body surface area was given subcutaneously to pregnant hamsters on gestation day 8. No neural tube defects were reported after a dose at 2.2 times the MDD. Pentazocine is not recommended for use in pregnant women during or immediately prior to labor or obstetric delivery when use of other analgesic techniques is more appropriate. Opioids can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Patients receiving injectable pentazocine during labor have experienced no adverse effects other than those that occur with commonly used analgesics. Further, prolonged maternal use of opioids, such as pentazocine, during pregnancy may result in neonatal opioid withdrawal syndrome (NOWS). Severe symptoms may require pharmacologic therapy managed by clinicians familiar with neonatal opioid withdrawal. Monitor the neonate for withdrawal symptoms including rapid breathing, irritability, hyperactivity, abnormal sleep pattern, high-pitched crying, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity of opioid withdrawal may vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination by the newborn.[30219]

Talwin

Rx, schedule IV

Synthetic opiate agonist-antagonist analgesic
One-sixth to one-third as potent as morphine
Less incidence of adverse reactions than with morphine and other opiates

Dosage should be modified depending on clinical response and degree of hepatic impairment, but no quantitative recommendations are available. If repeated doses are required, the dosing interval should be lengthened or the dosage reduced.

CrCl > 50 ml/min: no dosage adjustment required.
CrCl 10—50 ml/min: reduce dose by 25%.
CrCl < 10 ml/min: reduce dose by 50%.

Acetaminophen; Caffeine; Dihydrocodeine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as dihydrocodeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce the analgesic effects of dihydrocodeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Acetaminophen; Codeine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Acetaminophen; Hydrocodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Acetaminophen; Oxycodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as oxycodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of oxycodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Alfentanil: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as alfentanil. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Alprazolam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Amantadine: (Moderate) Use pentazocine with caution in any patient receiving anticholinergic agents. Coadministration of pentazocine with amantadine may result in additive anticholinergic effects, such as urinary retention and constipation.
Amiloride: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when potassium-sparring diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when potassium-sparring diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Amobarbital: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Amoxapine: (Major) Concomitant use of pentazocin and amoxapine may cause excessive sedation and somnolence. Limit the use of pentazocine and amoxapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Anticholinergics: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Aripiprazole: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Asenapine: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Aspirin, ASA; Butalbital; Caffeine: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Aspirin, ASA; Caffeine; Orphenadrine: (Major) Concomitant use of pentazocine with orphenadrine may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with orphenadrine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Aspirin, ASA; Carisoprodol: (Major) Concomitant use of pentazocine with carisoprodol may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Aspirin, ASA; Carisoprodol; Codeine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist. (Major) Concomitant use of pentazocine with carisoprodol may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Aspirin, ASA; Oxycodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as oxycodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of oxycodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Atenolol; Chlorthalidone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Atropine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Atropine; Difenoxin: (Major) Pentazocine may partially block the analgesic, respiratory depressant and CNS depressant effects of pure opiate agonists. Due to their antagonistic properties, pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Pentazocine may also be used concurrently with some opiate agonists and cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of pure opiate agonist used; antagonistic effects are more common at low to moderate doses of the pure opiate agonist. For example, some patients who received methadone for the daily treatment of narcotic dependence have experienced withdrawal symptoms after receiving pentazocine. Withdrawal symptoms may include anxiety, agitation, mood changes, hallucinations, dysphoria, weakness, and diarrhea. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
atypical antipsychotic: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Azelastine: (Moderate) An enhanced CNS depressant effect may occur when azelastine is combined with other CNS depressants including pentazocine.
Azelastine; Fluticasone: (Moderate) An enhanced CNS depressant effect may occur when azelastine is combined with other CNS depressants including pentazocine.
Azilsartan; Chlorthalidone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Baclofen: (Major) Concomitant use of pentazocine with baclofen may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with baclofen to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Barbiturates: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Belladonna; Opium: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as opium. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Benzhydrocodone; Acetaminophen: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as benzhydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. (Moderate) Theoretically, concurrent use of methylene blue and pentazocine may increase the risk of serotonin syndrome. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and pentazocine increases central serotonin effects. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between intravenously administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death.
Benztropine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Brexpiprazole: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Budesonide; Glycopyrrolate; Formoterol: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bumetanide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Buprenorphine: (Major) Avoid concomitant use of pentazocine with buprenorphine. Coadministration may reduce the analgesic effect of either drug and/or precipitate withdrawal symptoms.
Buprenorphine; Naloxone: (Major) Avoid concomitant use of pentazocine with buprenorphine. Coadministration may reduce the analgesic effect of either drug and/or precipitate withdrawal symptoms.
Bupropion: (Moderate) Plasma concentrations of opiate agents metabolized by CYP2D6, such as pentazocine, may be increased if bupropion, an inhibitor of the CYP2D6 isoenzyme, is added. Dosage reductions of pentazocine may be needed. Conversely, if bupropion therapy is discontinued, dosages of pentazocine may need to be adjusted upward in some patients.
Bupropion; Naltrexone: (Major) When naltrexone is used as adjuvant treatment of opiate or alcohol dependence, use is contraindicated in patients currently receiving mixed opiate agonists/antagonists. Naltrexone will antagonize the therapeutic benefits of mixed opiate agonists/antagonists and will induce a withdrawal reaction in patients with physical dependence to opioids. Also, patients should be opiate-free for at least 7 to 10 days prior to initiating naltrexone therapy. If there is any question of opioid use in the past 7-10 days and the patient is not experiencing opioid withdrawal symptoms and/or the urine is negative for opioids, a naloxone challenge test needs to be performed. If a patient receives naltrexone and an opiate agonist is needed for an emergency situation, large doses of opiate agonists may ultimately overwhelm naltrexone antagonism of opiate receptors. Immediately following administration of exogenous opiate agonists, the opiate plasma concentration may be sufficient to overcome naltrexone competitive blockade, but the patient may experience deeper and more prolonged respiratory depression and thus, may be in danger of respiratory arrest and circulatory collapse. Non-receptor mediated actions like facial swelling, itching, generalized erythema, or bronchoconstriction may occur presumably due to histamine release. A rapidly acting opiate agonist is preferred as the duration of respiratory depression will be shorter. Patients receiving naltrexone may also experience opiate side effects (respiratory insufficiency or arrest or circulatory collapse) with low doses of opiate agonists. If the opiate agonist is taken in such a way that high concentrations remain in the body beyond the time naltrexone exerts its therapeutic effects, serious side effects may occur. (Moderate) Plasma concentrations of opiate agents metabolized by CYP2D6, such as pentazocine, may be increased if bupropion, an inhibitor of the CYP2D6 isoenzyme, is added. Dosage reductions of pentazocine may be needed. Conversely, if bupropion therapy is discontinued, dosages of pentazocine may need to be adjusted upward in some patients.
Buspirone: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include buspirone.
Butabarbital: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Butalbital; Acetaminophen: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Butalbital; Acetaminophen; Caffeine: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Butalbital; Acetaminophen; Caffeine; Codeine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist. (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Butalbital; Aspirin; Caffeine; Codeine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist. (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Butorphanol: (Major) Concomitant use of butorphanol and pentazocine can potentiate respiratory depression, CNS depression (e.g., dizziness, impaired mental function), and sedation. If these drugs need to be administered together, use the smallest effective dose and the longest dosing frequency of butorphanol.
Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Cannabidiol: (Moderate) Concomitant use of mixed opioid agonists/antagonists with cannabidiol may cause excessive sedation and somnolence. Limit the use of mixed opioid agonists/antagonists with cannabidiol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opioid agonist/antagonist is initiated in a patient taking cannabidiol, reduce initial dosage and titrate to clinical response. If cannabidiol is initiated in a patient taking a mixed opioid agonist/antagonist, use a lower initial dose of cannabidiol and titrate to clinical response. Educate patients about the risks and symptoms of excessive CNS depression.
Capsaicin; Metaxalone: (Major) Concomitant use of pentazocine with metaxalone may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with metaxalone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose. Concomitant use of pentazocine and metaxalone increases the risk for serotonin syndrome. Avoid concomitant use if possible and monitor for serotonin syndrome if use is necessary.
Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Carbidopa; Levodopa; Entacapone: (Major) Concomitant use of opiate agonists-antagonists with other central nervous system (CNS) depressants, such as COMT inhibitors, can potentiate the effects of the opiate agonists-antagonist and may lead to additive CNS or respiratory depression. Prior to concurrent use of a mixed opiate agonist-antagonist in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. If these agents are used together, reduced dosages may be necessary. Carefully monitor the patient for hypotension and CNS depression.
Cariprazine: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Carisoprodol: (Major) Concomitant use of pentazocine with carisoprodol may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Celecoxib; Tramadol: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as tramadol. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. There is also a potential increased risk of seizures if tramadol and pentazocine are given concurrently. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Cenobamate: (Moderate) Concomitant use of pentazocine with cenobamate may cause excessive sedation and somnolence. Limit the use of pentazocine with cenobamate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Cetirizine: (Moderate) Concurrent use of cetirizine/levocetirizine with pentazocine should generally be avoided. Coadministration may increase the risk of CNS depressant-related side effects. If concurrent use is necessary, monitor for excessive sedation and somnolence.
Cetirizine; Pseudoephedrine: (Moderate) Concurrent use of cetirizine/levocetirizine with pentazocine should generally be avoided. Coadministration may increase the risk of CNS depressant-related side effects. If concurrent use is necessary, monitor for excessive sedation and somnolence.
Chlordiazepoxide: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Chlordiazepoxide; Amitriptyline: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Chlordiazepoxide; Clidinium: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Chlorothiazide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Chlorpheniramine; Codeine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as dihydrocodeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce the analgesic effects of dihydrocodeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Chlorpheniramine; Hydrocodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Chlorpromazine: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Chlorthalidone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Chlorthalidone; Clonidine: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Chlorzoxazone: (Major) Concomitant use of pentazocine with chlorzoxazone may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with chlorzoxazone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Clobazam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Clonazepam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Clorazepate: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Clozapine: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Codeine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Codeine; Guaifenesin: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Codeine; Guaifenesin; Pseudoephedrine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Codeine; Phenylephrine; Promethazine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist. (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Codeine; Promethazine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist. (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
COMT inhibitors: (Major) Concomitant use of opiate agonists-antagonists with other central nervous system (CNS) depressants, such as COMT inhibitors, can potentiate the effects of the opiate agonists-antagonist and may lead to additive CNS or respiratory depression. Prior to concurrent use of a mixed opiate agonist-antagonist in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. If these agents are used together, reduced dosages may be necessary. Carefully monitor the patient for hypotension and CNS depression.
Cyclobenzaprine: (Major) Concomitant use of pentazocine with cyclobenzaprine may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with cyclobenzaprine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose. Concomitant use of pentazocine and cyclobenzaprine increases the risk for serotonin syndrome. Avoid concomitant use if possible and monitor for serotonin syndrome if use is necessary.
Dantrolene: (Major) Concomitant use of pentazocine with dantrolene may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with dantrolene to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Daridorexant: (Major) Concomitant use of opiate agonists-antagonists with daridorexant may cause excessive sedation and somnolence. Limit the use of opiate agonists-antagonists with daridorexant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Deutetrabenazine: (Major) Concomitant use of mixed opiate agonists/antagonists with deutetrabenazine may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with deutetrabenazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking deutetrabenazine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If deutetrabenazine is prescribed for a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of deutetrabenazine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Dextromethorphan; Bupropion: (Moderate) Plasma concentrations of opiate agents metabolized by CYP2D6, such as pentazocine, may be increased if bupropion, an inhibitor of the CYP2D6 isoenzyme, is added. Dosage reductions of pentazocine may be needed. Conversely, if bupropion therapy is discontinued, dosages of pentazocine may need to be adjusted upward in some patients.
Diazepam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If parental diazepam is used with a mixed opiate agonist/antagonist, reduce the mixed opiate agonist/antagonist dosage by at least 1/3. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Dicyclomine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Difelikefalin: (Moderate) Monitor for dizziness, somnolence, mental status changes, and gait disturbances if concomitant use of difelikefalin with CNS depressants is necessary. Concomitant use may increase the risk for these adverse reactions.
Diphenoxylate; Atropine: (Major) Pentazocine may partially block the analgesic, respiratory depressant and CNS depressant effects of pure opiate agonists. Due to their antagonistic properties, pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Pentazocine may also be used concurrently with some opiate agonists and cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of pure opiate agonist used; antagonistic effects are more common at low to moderate doses of the pure opiate agonist. For example, some patients who received methadone for the daily treatment of narcotic dependence have experienced withdrawal symptoms after receiving pentazocine. Withdrawal symptoms may include anxiety, agitation, mood changes, hallucinations, dysphoria, weakness, and diarrhea. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Disopyramide: (Moderate) Use pentazocine with caution in any patient receiving medication with anticholinergic activity. Coadministration of pentazocine with disopyramide may result in additive anticholinergic effects, such as urinary retention and constipation.
Dronabinol: (Moderate) Concomitant use of dronabinol with other CNS depressants, such as pentazocine, can potentiate the effects of dronabinol on respiratory depression.
Droperidol: (Major) Mixed opiate agonists/antagonists have additive or potentiating effects with droperidol. Following administration of droperidol, lower doses of the other CNS depressant should be used.
Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Entacapone: (Major) Concomitant use of opiate agonists-antagonists with other central nervous system (CNS) depressants, such as COMT inhibitors, can potentiate the effects of the opiate agonists-antagonist and may lead to additive CNS or respiratory depression. Prior to concurrent use of a mixed opiate agonist-antagonist in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. If these agents are used together, reduced dosages may be necessary. Carefully monitor the patient for hypotension and CNS depression.
Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Esketamine: (Major) Closely monitor patients receiving esketamine and pentazocine for sedation and other CNS depressant effects. Instruct patients who receive a dose of esketamine not to drive or engage in other activities requiring alertness until the next day after a restful sleep.
Estazolam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Eszopiclone: (Moderate) Concomitant use of pentazocine with eszopiclone can potentiate respiratory depression, CNS depression, and sedation. In addition, the risk of next-day psychomotor impairment is increased during co-administration, which may decrease the ability to perform tasks requiring full mental alertness such as driving. Pentazocine should be used cautiously in any patient receiving eszopiclone. If concurrent use is necessary, a dose reduction of one or both medications may be required.
Ethacrynic Acid: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Ethanol: (Major) Advise patients to avoid alcohol consumption while taking CNS depressants. Alcohol consumption may result in additive CNS depression.
Fenfluramine: (Moderate) Concomitant use of opioid agonists-antagonists with fenfluramine may cause excessive sedation and somnolence. Limit the use of opioid agonists with fenfluramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Fentanyl: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as fentanyl. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Flavoxate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Flibanserin: (Moderate) The concomitant use of flibanserin with CNS depressants, such as mixed opiate agonists/antagonists or their combinations (e.g., buprenorphine; naloxone), may increase the risk of CNS depression (e.g., dizziness, somnolence) compared to the use of flibanserin alone. Patients should avoid activities requiring full alertness (e.g., operating machinery or driving) until at least 6 hours after each dose and until they know how flibanserin affects them.
Fluphenazine: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Flurazepam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Food: (Major) Advise patients to avoid cannabis use while taking CNS depressants due to the risk for additive CNS depression and potential for other cognitive adverse reactions.
Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Furosemide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Gabapentin: (Major) Concomitant use of pentazocine with gabapentin may cause excessive sedation, somnolence, and respiratory depression. Limit the use of pentazocine with gabapentin to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, initiate gabapentin at the lowest recommended dose and monitor patients for symptoms of respiratory depression and sedation. Use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and respiratory depression.
Glycopyrrolate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Glycopyrrolate; Formoterol: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Guaifenesin; Hydrocodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Haloperidol: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include haloperidol.
Homatropine; Hydrocodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Hydrocodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Hydrocodone; Ibuprofen: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Hydrocodone; Pseudoephedrine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydrocodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of hydrocodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Hydromorphone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as hydromorphone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Hyoscyamine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. (Moderate) Theoretically, concurrent use of methylene blue and pentazocine may increase the risk of serotonin syndrome. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and pentazocine increases central serotonin effects. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between intravenously administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death.
Ibuprofen; Oxycodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as oxycodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of oxycodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Iloperidone: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Indacaterol; Glycopyrrolate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Indapamide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when indapamide is administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Irbesartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Lasmiditan: (Moderate) Concomitant use of pentazocine with lasmiditan may cause excessive sedation, somnolence, and serotonin syndrome. Limit the use of pentazocine with lasmiditan to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome.
Lemborexant: (Moderate) Concomitant use of opiate agonists-antagonists with lemborexant may cause excessive sedation and somnolence. Limit the use of the opiate agonists-antagonist with lemborexant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Levocetirizine: (Moderate) Concurrent use of cetirizine/levocetirizine with pentazocine should generally be avoided. Coadministration may increase the risk of CNS depressant-related side effects. If concurrent use is necessary, monitor for excessive sedation and somnolence.
Levorphanol: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as levorphanol. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Linezolid: (Major) Avoid concomitant use of pentazocine in patients receiving linezolid due to the risk of serotonin syndrome. If coadministration or administration of pentazocine within 14 days of linezolid is warranted, carefully monitor patients, especially during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. Concomitant use may also cause CNS excitation or hypertension.
Lisinopril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Lofexidine: (Moderate) Monitor for excessive hypotension and sedation during coadministration of lofexidine and pentazocine. Lofexidine can potentiate the effects of CNS depressants.
Loop diuretics: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Lorazepam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Losartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Lumateperone: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Lurasidone: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Maprotiline: (Moderate) Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity. Coadministration of pentazocine with maprotiline may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation.
Meperidine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as meperidine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of meperidine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Meprobamate: (Moderate) Concomitant use of pentazocine with meprobamate can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously meprobamate. If concurrent use is necessary, a dose reduction of one or both medications may be required.
Metaxalone: (Major) Concomitant use of pentazocine with metaxalone may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with metaxalone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose. Concomitant use of pentazocine and metaxalone increases the risk for serotonin syndrome. Avoid concomitant use if possible and monitor for serotonin syndrome if use is necessary.
Methadone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as methadone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. (Moderate) Theoretically, concurrent use of methylene blue and pentazocine may increase the risk of serotonin syndrome. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and pentazocine increases central serotonin effects. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between intravenously administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death.
Methocarbamol: (Major) Concomitant use of pentazocine with methocarbamol may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with methocarbamol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Methohexital: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Methscopolamine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Methyclothiazide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Methylene Blue: (Moderate) Theoretically, concurrent use of methylene blue and pentazocine may increase the risk of serotonin syndrome. Methylene blue is a thiazine dye that is also a potent, reversible inhibitor of the enzyme responsible for the catabolism of serotonin in the brain (MAO-A) and pentazocine increases central serotonin effects. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between intravenously administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Serotonin syndrome is characterized by rapid development of various symptoms such as hyperthermia, hypertension, myoclonus, rigidity, hyperhidrosis, incoordination, diarrhea, mental status changes (e.g., confusion, delirium, or coma), and in rare cases, death.
Metolazone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Midazolam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Minocycline: (Minor) Injectable minocycline contains magnesium sulfate heptahydrate. Because of the CNS-depressant effects of magnesium sulfate, additive central-depressant effects can occur following concurrent administration with CNS depressants such as pentazocine. Caution should be exercised when using these agents concurrently.
Mirtazapine: (Major) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving mirtazapine.
Molindone: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as molindone, can potentiate respiratory depression, CNS depression, and sedation.
Monoamine oxidase inhibitors: (Major) The use of pentazocine is not recommended in patients who have received a monoamine oxidase inhibitor (MAOI) within the previous 14 days due to a risk for serotonin syndrome or opioid toxicity, including respiratory depression. If urgent use of an opioid like pentazocine is necessary, use test doses and frequent titration of small doses to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression.
Morphine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as morphine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of morphine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Morphine; Naltrexone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as morphine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of morphine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Nabilone: (Major) The use of nabilone with opiate agonist/antagonists may lead to additive CNS or respiratory depression, profound sedation, or coma. If these agents are used together, a reduced dosage of either drug may be advisable. Prior to concurrent use, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Cross-tolerance may occur between these drugs over time. Consider the patient's use of alcohol or illicit drugs. Carefully monitor the patient for hypotension, CNS depression, and respiratory depression.
Nalbuphine: (Major) Avoid concomitant use of pentazocine with nalbuphine. Coadministration may reduce the analgesic effect of either drug and/or precipitate withdrawal symptoms.
Nalmefene: (Major) Naloxone, nalmefene, and naltrexone act as opiate antagonists at all opiate receptors. Administration of an opiate antagonist will override the actions of mixed opiate agonist/antagonists and precipitate opioid withdrawal effects. While opiate antagonism may be desirable in a patient with respiratory depression caused by the mixed opiate agonist/antagonist, severe pain can be unmasked and opiate withdrawal symptoms may occur in patients who have received chronic opiate agonist therapy.
Naltrexone: (Major) When naltrexone is used as adjuvant treatment of opiate or alcohol dependence, use is contraindicated in patients currently receiving mixed opiate agonists/antagonists. Naltrexone will antagonize the therapeutic benefits of mixed opiate agonists/antagonists and will induce a withdrawal reaction in patients with physical dependence to opioids. Also, patients should be opiate-free for at least 7 to 10 days prior to initiating naltrexone therapy. If there is any question of opioid use in the past 7-10 days and the patient is not experiencing opioid withdrawal symptoms and/or the urine is negative for opioids, a naloxone challenge test needs to be performed. If a patient receives naltrexone and an opiate agonist is needed for an emergency situation, large doses of opiate agonists may ultimately overwhelm naltrexone antagonism of opiate receptors. Immediately following administration of exogenous opiate agonists, the opiate plasma concentration may be sufficient to overcome naltrexone competitive blockade, but the patient may experience deeper and more prolonged respiratory depression and thus, may be in danger of respiratory arrest and circulatory collapse. Non-receptor mediated actions like facial swelling, itching, generalized erythema, or bronchoconstriction may occur presumably due to histamine release. A rapidly acting opiate agonist is preferred as the duration of respiratory depression will be shorter. Patients receiving naltrexone may also experience opiate side effects (respiratory insufficiency or arrest or circulatory collapse) with low doses of opiate agonists. If the opiate agonist is taken in such a way that high concentrations remain in the body beyond the time naltrexone exerts its therapeutic effects, serious side effects may occur.
Nefazodone: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as nefazodone, can potentiate respiratory depression, CNS depression, and sedation.
Neostigmine; Glycopyrrolate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Olanzapine: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Olanzapine; Fluoxetine: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Olanzapine; Samidorphan: (Contraindicated) Salmidorphan is contraindicated in patients who are using opiate agonists or undergoing acute opioid withdrawal. Salmidorphan increases the risk of precipitating acute opioid withdrawal in patients dependent on opioids. Before initiating salmidorphan, there should be at least a 7-day opioid-free interval from the last use of short-acting opioids, and at least a 14-day opioid-free interval from the last use of long-acting opioids. In emergency situations, if a salmidorphan-treated patient requires opiates for anesthesia or analgesia, discontinue salmidorphan. The opiate agonist should be administered by properly trained individual(s), and the patient properly monitored in a setting equipped and staffed for cardiopulmonary resuscitation. In non-emergency situations, if a salmidorphan-treated patient requires opiate agonist treatment (e.g., for analgesia) discontinue salmidorphan at least 5 days before opioid treatment. Salmidorphan, as an opioid antagonist, may cause opioid treatment to be less effective or ineffective shortly after salmidorphan discontinuation. (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Oliceridine: (Major) Avoid concomitant use of oliceridine with opioid agonists-antagonists. Coadministration may reduce the analgesic effect of oliceridine and/or precipitate withdrawal symptoms.
Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Olmesartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Opicapone: (Major) Concomitant use of opiate agonists-antagonists with other central nervous system (CNS) depressants, such as COMT inhibitors, can potentiate the effects of the opiate agonists-antagonist and may lead to additive CNS or respiratory depression. Prior to concurrent use of a mixed opiate agonist-antagonist in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. If these agents are used together, reduced dosages may be necessary. Carefully monitor the patient for hypotension and CNS depression.
Orphenadrine: (Major) Concomitant use of pentazocine with orphenadrine may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with orphenadrine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Oxazepam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Oxybutynin: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Oxycodone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as oxycodone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of oxycodone. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Oxymorphone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as oxymorphone. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Ozanimod: (Moderate) Coadministration of pentazocine, an opioid agonist/antagonist, with ozanimod is not recommended due to the potential for serotonergic effects. An active metabolite of ozanimod inhibits MAO-B, which may increase the potential for serotonin syndrome or increased blood pressure. If concomitant use of pentazocine is warranted in a patient taking an MAO inhibitor, carefully observe the patient and monitor blood pressure, particularly during treatment initiation and dose adjustment. Discontinue serotonergic agents if serotonin syndrome is suspected. Although a small number of patients treated with ozanimod were concomitantly exposed to opioids, this exposure was not adequate to rule out the possibility of an adverse reaction from coadministration.
Paliperidone: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Pentobarbital: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Perphenazine: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Perphenazine; Amitriptyline: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Phenobarbital: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Phenothiazines: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Pimozide: (Moderate) Concomitant use of codeine with other central nervous system (CNS) depressants, such as pimozide, can potentiate the effects of pentazocine and may lead to additive CNS or respiratory depression, profound sedation, or coma. If these agents are used together, a reduced dosage of pentazocine may be required. Carefully monitor the patient for hypotension, CNS depression, and respiratory depression. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.
Potassium-sparing diuretics: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when potassium-sparring diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Pramipexole: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as pramipexole, can potentiate respiratory depression, CNS depression, and sedation.
Pregabalin: (Major) Concomitant use of pentazocine with pregabalin may cause excessive sedation, somnolence, and respiratory depression. Limit the use of pentazocine with pregabalin to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, initiate pregabalin at the lowest recommended dose and monitor patients for symptoms of respiratory depression and sedation. Use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and respiratory depression.
Primidone: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Procarbazine: (Major) Patients receiving concurrent pentazocine and MAOI inhbitors may be at increased risk for developing serotonin syndrome; pentazocine should be used cautiously in patients receiving other drugs with MAOI activity, such as procarbazine.
Prochlorperazine: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Promethazine: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Promethazine; Dextromethorphan: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Promethazine; Phenylephrine: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Propantheline: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Quazepam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Quetiapine: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Quinapril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Rasagiline: (Major) The CNS-depressant effects of MAOIs can be potentiated with concomitant administration of other drugs known to cause CNS depression, such as pentazocine. Patients receiving concurrent pentazocine and monoamine oxidase inhibitors (MAOIs) may be at increased risk for developing serotonin syndrome. If concurrent use is clinically indicated, observe the patient for signs or symptoms of serotonin excess such as restlessness, myoclonus, confusion, hyperreflexia, diaphoresis, shivering, tachycardia, and tremor. Use cautiously with MAOIs; warn patients to not drive or perform other hazardous activities until they know how this drug combination affects them.
Remifentanil: (Major) Concurrent use of pentazocine may reduce the analgesic effect of remifentanil and/or precipitate withdrawal symptoms. If coadministration is necessary, carefully observe the patient, especially during remifentanil initiation and dosage adjustment. Consider discontinuing remifentanil and instituting alternative analgesia if the patient is not responding appropriately. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Remimazolam: (Major) Concomitant use of opioid agonists-antagonists with remimazolam may cause respiratory depression, hypotension, profound sedation, and death. Titrate the dose of remimazolam to the desired clinical response and continuously monitor sedated patients for hypotension, airway obstruction, hypoventilation, apnea, and oxygen desaturation.
Risperidone: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Rotigotine: (Moderate) Concomitant use of rotigotine with other CNS depressants, such as opiate agonists-antagonists, can potentiate the sedation effects of rotigotine.
Safinamide: (Contraindicated) Concomitant use of safinamide with opioids is contraindicated due to the risk of serotonin syndrome. Allow at least 14 days between discontinuation of safinamide and initiation of treatment with opioids.
Scopolamine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Secobarbital: (Moderate) Concomitant use of pentazocine with other CNS depressants can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving these agents, which may include barbiturates.
Sedating H1-blockers: (Moderate) Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity. Coadministration of pentazocine with sedating H1-blockers may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation.
Selective serotonin reuptake inhibitors: (Major) Because of the potential risk and severity of serotonin syndrome reactions, caution should be observed when administering selective serotonin reuptake inhibitors (SSRIs) with other drugs that have serotonergic properties such as pentazocine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome occurs, discontinue the offending agent(s) and institute appropriate therapy.
Selegiline: (Contraindicated) Coadministration of pentazocine and selegiline is contraindicated due to a risk for serotonin syndrome. At least 14 days should elapse between discontinuation of selegiline and initiation of treatment with pentazocine. After stopping treatment with pentazocine, a time period equal to 4 to 5 half-lives of pentazocine or any active metabolite should elapse before starting therapy with selegiline.
Serotonin norepinephrine reuptake inhibitors: (Major) Because of the potential risk and severity of serotonin syndrome or neuroleptic malignant syndrome-like reactions, caution should be observed when administering serotonin norepinephrine reuptake inhibitors (SNRIs) with other drugs that have serotonergic properties such as pentazocine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Patients receiving this combination should be monitored for the emergence of serotonin syndrome or neuroleptic malignant syndrome-like reactions.
Solifenacin: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug, such as solifenacin. The concomitant use of pentazocine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Spironolactone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when potassium-sparring diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Spironolactone; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when potassium-sparring diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Stiripentol: (Major) Concomitant use of mixed opioid agonists/antagonists like pentazocine with stiripentol may cause excessive sedation and somnolence. Limit the use of pentazocine with stiripentol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If pentazocine is initiated in a patient taking stiripentol, reduce initial dosage and titrate to clinical response. If stiripentol is initiated a patient taking pentazocine, use a lower initial dose of stiripentol and titrate to clinical response. Educate patients about the risks and symptoms of excessive CNS depression.
Sufentanil: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as sufentanil. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Suvorexant: (Moderate) CNS depressant drugs may have cumulative effects when administered concurrently and they should be used cautiously with suvorexant. A reduction in dose of the CNS depressant may be needed. These agents include mixed opiate agonists/antagonists.
Tapentadol: (Major) Avoid the concomitant use of tapentadol and opiate agonists/antagonists (e.g., buprenorphine, butorphanol, nalbuphine, or pentazocine). Opiate agonists/antagonists may partially block the analgesic, respiratory depressant, and CNS depressant effects of tapentadol. Due to their antagonistic properties, opiate agonists/antagonists may cause withdrawal symptoms in patients receiving chronic opiate agonists. These agents may also be used concurrently with some opiate agonists and cause additive CNS, respiratory, and hypotensive effects. Consider dose reduction of the opiate agonist in situations of concomitant prescription. The additive or antagonistic effects are dependent upon the dose of pure opiate agonist used; antagonistic effects are more common at low to moderate doses of the pure opiate agonist.
Tedizolid: (Minor) Caution is warranted with the concurrent use of tedizolid and pentazocine. Tedizolid is an antibiotic that is also a weak reversible, non-selective inhibitor of MAO. Serious CNS reactions, such as serotonin syndrome, have been reported during the concurrent use of linezolid, which is structurally similar to tedizolid, and psychiatric medications that enhance central serotonergic activity; therefore, caution is warranted with concomitant use of other agents with serotonergic activity, including pentazocine.
Telmisartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Temazepam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Tetrabenazine: (Moderate) Additive effects are possible when tetrabenazine is combined with other drugs that cause CNS depression, like pentazocine. Concurrent use of tetrabenazine and pentazocine can increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, dizziness, and orthostatic hypotension.
Thalidomide: (Major) Avoid the concomitant use of thalidomide with other central nervous system depressants such as pentazocine due to the potential for additive sedative effects.
Thiazide diuretics: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Thioridazine: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respirator y depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Thiothixene: (Moderate) Thiothixene can potentiate the CNS-depressant action of other drugs such as pentazocine. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Tizanidine: (Major) Concomitant use of pentazocine with tizanidine may cause respiratory depression, profound sedation, and death. Limit the use of pentazocine with tizanidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose.
Tobacco: (Major) Advise patients to avoid smoking tobacco while taking pentazocine. People who smoke have been observed to metabolize 40% more pentazocine than non-smokers. Enhanced metabolic clearance may reduce pentazocine efficacy.
Tolcapone: (Major) Concomitant use of opiate agonists-antagonists with other central nervous system (CNS) depressants, such as COMT inhibitors, can potentiate the effects of the opiate agonists-antagonist and may lead to additive CNS or respiratory depression. Prior to concurrent use of a mixed opiate agonist-antagonist in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. If these agents are used together, reduced dosages may be necessary. Carefully monitor the patient for hypotension and CNS depression.
Tolterodine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug, such as tolterodine. The concomitant use of pentazocine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Torsemide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Tramadol: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as tramadol. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. There is also a potential increased risk of seizures if tramadol and pentazocine are given concurrently. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Tramadol; Acetaminophen: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as tramadol. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. There is also a potential increased risk of seizures if tramadol and pentazocine are given concurrently. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Trazodone: (Moderate) Because of the potential risk and severity of CNS depression, respiratory depression, and serotonin syndrome, caution should be observed when administering pentazocine with trazodone. Inform patients taking this combination of the possible increased risks and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Triamterene: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when potassium-sparring diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Triamterene; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when potassium-sparring diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Triazolam: (Major) Concomitant use of mixed opiate agonists/antagonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of mixed opiate agonists/antagonists with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If a mixed opiate agonist/antagonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the mixed opiate agonist/antagonist and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking a mixed opiate agonist/antagonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Tricyclic antidepressants: (Moderate) Pain medications such as pentazocine should be combined cautiously with tricyclic antidepressants due to the possibility of additive CNS depression, respiratory depression, hypotension, or decreased intestinal motility. Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering tricyclic antidepressants with other drugs that have serotonergic properties such as pentazocine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, tricyclic antidepressant and concurrent serotonergic agents should be discontinued.
Trifluoperazine: (Moderate) Concomitant use of pentazocine with other CNS depressants, such as phenothiazines, can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously with phenothiazines.
Trihexyphenidyl: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug. The concomitant use of pentazocine and anticholinergic medications may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Trimethobenzamide: (Moderate) The concurrent use of trimethobenzamide with other medications that cause CNS depression, like pentazocine, may potentiate the effects of either trimethobenzamide or pentazocine.
Trospium: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when pentazocine is used concomitantly with an anticholinergic drug, such as trospium. The concomitant use of pentazocine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with pentazocine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Vigabatrin: (Moderate) Vigabatrin may cause somnolence and fatigue. Drugs that can cause CNS depression, if used concomitantly with vigabatrin, may increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, and dizziness. Caution should be used when vigabatrin is given with pentazocine.
Vilazodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering pentazocine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Vortioxetine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vortioxetine with other drugs that have serotonergic properties such as pentazocine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, vortioxetine and concurrent serotonergic agents should be discontinued.
Zaleplon: (Moderate) Concomitant use of pentazocine with zaleplon can potentiate respiratory depression, CNS depression, and sedation. Pentazocine should be used cautiously in any patient receiving zaleplon. If concurrent use is necessary, a dose reduction of one or both medications may be required.
Ziconotide: (Moderate) Concurrent use of ziconotide and opiate agonists-antagonists may result in an increased incidence of dizziness and confusion. Ziconotide neither interacts with opiate receptors nor potentiates opiate-induced respiratory depression. However, in animal models, ziconotide did potentiate gastrointestinal motility reduction by opioid agonists.
Ziprasidone: (Moderate) Coadministration of pentazocine with atypical antipsychotics may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation. Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity.
Zolpidem: (Moderate) Concomitant use of pentazocine with zolpidem can potentiate respiratory depression, CNS depression, and sedation. In addition, sleep-related behaviors, such as sleep-driving, are more likely to occur during concurrent use of zolpidem and other CNS depressants than with zolpidem alone. Pentazocine should be used cautiously in any patient receiving zolpidem. If concurrent use is necessary, a dose reduction of one or both medications may be required. For Intermezzo brand of sublingual zolpidem tablets, reduce the dose to 1.75 mg/night.