DRUG INTERACTIONS
Acetaminophen; Butalbital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Acetaminophen; Butalbital; Caffeine: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Acetaminophen; Butalbital; Caffeine; Codeine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants. (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Acetaminophen; Caffeine; Dihydrocodeine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants.
Acetaminophen; Caffeine; Magnesium Salicylate; Phenyltoloxamine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Acetaminophen; Caffeine; Phenyltoloxamine; Salicylamide: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Acetaminophen; Chlorpheniramine; Phenylephrine; Phenyltoloxamine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Acetaminophen; Codeine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants.
Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Acetaminophen; Dichloralphenazone; Isometheptene: (Moderate) Additive CNS depression is possible if skeletal muscle relaxants are used concomitantly with other CNS depressants. Dosage adjustments of one or both medications may be necessary.
Acetaminophen; Diphenhydramine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Acetaminophen; Hydrocodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Acetaminophen; Oxycodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 oxycodone or oxycodone; naloxone is initiated in a patient taking a skeletal muscle relaxant, use an initial dose of oxycodone at one-third to one-half the usual dosage and titrate to clinical response; reduced initial doses of oxycodone; naltrexone, aspirin, ASA; oxycodone, and ibuprofen; oxycodone are also recommended. If a decision is made to start treatment with acetaminophen; oxycodone extended-release tablets, start with 1 tablet PO every 12 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Acetaminophen; Pentazocine: (Moderate) Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity. Coadministration of pentazocine with skeletal muscle relaxants may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation.
Acetaminophen; Tramadol: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Acrivastine; Pseudoephedrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Alfentanil: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Aliskiren; Amlodipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Alprazolam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Amitriptyline: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Amitriptyline; Chlordiazepoxide: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression. (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Amlodipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Amlodipine; Atorvastatin: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Amlodipine; Benazepril: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Amlodipine; Hydrochlorothiazide, HCTZ; Olmesartan: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Amlodipine; Hydrochlorothiazide, HCTZ; Valsartan: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Amlodipine; Olmesartan: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Amlodipine; Telmisartan: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Amlodipine; Valsartan: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Amobarbital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Amoxapine: (Moderate) Skeletal muscle relaxants should be combined cautiously with cyclic antidepressants like maprotiline because they could cause additive CNS depressant effects. Depending on the specific agent (e.g., cyclobenzaprine, and orphenadrine), additive anticholinergic effects may also be seen. Clinicians should note that antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. Patients should be monitored for excessive adverse effects from either agent.
Anxiolytics; Sedatives; and Hypnotics: (Moderate) Simultaneous use of dantrolene and other CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase CNS depression (e.g., drowsiness). A reduction in the dose of these medications may be considered to minimize additive sedative effects, if they occur. With hypnotic medications, the risk of next-day psychomotor impairment is increased during co-administration of other CNS depressants, which may decrease the ability to perform tasks requiring full mental alertness such as driving.
Apomorphine: (Moderate) Apomorphine causes significant somnolence. Concomitant administration of apomorphine and CNS depressants could result in additive depressant effects.
Aspirin, ASA; Butalbital; Caffeine: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Aspirin, ASA; Butalbital; Caffeine; Codeine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants. (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Aspirin, ASA; Caffeine; Dihydrocodeine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants.
Aspirin, ASA; Carisoprodol; Codeine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants.
Aspirin, ASA; Oxycodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 oxycodone or oxycodone; naloxone is initiated in a patient taking a skeletal muscle relaxant, use an initial dose of oxycodone at one-third to one-half the usual dosage and titrate to clinical response; reduced initial doses of oxycodone; naltrexone, aspirin, ASA; oxycodone, and ibuprofen; oxycodone are also recommended. If a decision is made to start treatment with acetaminophen; oxycodone extended-release tablets, start with 1 tablet PO every 12 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Atracurium: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Atropine; Difenoxin: (Moderate) Concurrent administration of diphenoxylate/difenoxin with dantrolene can potentiate the CNS-depressant effects of diphenoxylate/difenoxin. Use caution during coadministration.
Atropine; Diphenoxylate: (Moderate) Concurrent administration of diphenoxylate/difenoxin with dantrolene can potentiate the CNS-depressant effects of diphenoxylate/difenoxin. Use caution during coadministration.
Atropine; Hyoscyamine; Phenobarbital; Scopolamine: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Azelastine: (Moderate) An enhanced CNS depressant effect may occur when azelastine is combined with other CNS depressants including skeletal muscle relaxants.
Azelastine; Fluticasone: (Moderate) An enhanced CNS depressant effect may occur when azelastine is combined with other CNS depressants including skeletal muscle relaxants.
Bacitracin: (Minor) Use skeletal muscle relaxants cautiously in patients receiving systemic bacitracin. If bacitracin is administered parenterally during surgery, there may be increased skeletal muscle relaxation, and postoperative use may reinstate neuromuscular blockade.
Barbiturates: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Belladonna Alkaloids; Ergotamine; Phenobarbital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Belladonna; Opium: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Benzodiazepines: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Botulinum Toxins: (Moderate) Excessive neuromuscular weakness may be exacerbated by coadministration of a botulinum toxin with skeletal muscle relaxants. Advise patients to seek medical assistance if they develop any unusual symptoms (including difficulty with swallowing, speaking, or breathing or walking), or if any existing symptom worsens during use of a botulinum toxin.
Brompheniramine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Brompheniramine; Carbetapentane; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Brompheniramine; Dextromethorphan; Guaifenesin: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Brompheniramine; Guaifenesin; Hydrocodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Brompheniramine; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Brompheniramine; Pseudoephedrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Buprenorphine: (Moderate) Concomitant use of buprenorphine with other CNS depressants can lead to additive CNS depressive effects. Hypotension, profound sedation, coma, respiratory depression, or death may occur; examples of other CNS depressants can include skeletal muscle relaxants. Prior to concurrent use of buprenorphine 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. Consider the patient's use of alcohol or illicit drugs. A dose reduction of one or both drugs may be warranted. It is recommended that the injectable buprenorphine dose be halved for patients who receive other drugs with CNS depressant effects; for the buprenorphine transdermal patch, start with the 5 mcg/hour patch. Monitor patients for sedation or respiratory depression.
Buprenorphine; Naloxone: (Moderate) Concomitant use of buprenorphine with other CNS depressants can lead to additive CNS depressive effects. Hypotension, profound sedation, coma, respiratory depression, or death may occur; examples of other CNS depressants can include skeletal muscle relaxants. Prior to concurrent use of buprenorphine 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. Consider the patient's use of alcohol or illicit drugs. A dose reduction of one or both drugs may be warranted. It is recommended that the injectable buprenorphine dose be halved for patients who receive other drugs with CNS depressant effects; for the buprenorphine transdermal patch, start with the 5 mcg/hour patch. Monitor patients for sedation or respiratory depression.
Buspirone: (Moderate) Concomitant use of skeletal muscle relaxants with buspirone can result in additive CNS depression. Dosage adjustments of either or both medications may be necessary.
Butabarbital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Butorphanol: (Moderate) Concomitant use of butorphanol with other CNS depressants, such as dantrolene, can potentiate the effects of butorphanol on respiratory depression, CNS depression, and sedation.
Calcium-channel blockers: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Cannabidiol: (Moderate) Monitor for excessive sedation and somnolence during coadministration of cannabidiol and dantrolene. CNS depressants can potentiate the effects of cannabidiol.
Carbetapentane; Chlorpheniramine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbetapentane; Chlorpheniramine; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbetapentane; Diphenhydramine; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbetapentane; Guaifenesin: (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbetapentane; Guaifenesin; Phenylephrine: (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbetapentane; Phenylephrine: (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbetapentane; Phenylephrine; Pyrilamine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbetapentane; Pseudoephedrine: (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbetapentane; Pyrilamine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants. (Moderate) Drowsiness has been reported during administration of carbetapentane. An enhanced CNS depressant effect may occur when carbetapentane is combined with other CNS depressants including skeletal muscle relaxants.
Carbidopa; Levodopa; Entacapone: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including skeletal muscle relaxants, due to the possibility of additive sedation.
Carbinoxamine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Carbinoxamine; Hydrocodone; Phenylephrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Carbinoxamine; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Carbinoxamine; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Carbinoxamine; Pseudoephedrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chloral Hydrate: (Moderate) Simultaneous use of dantrolene and other CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase CNS depression (e.g., drowsiness). A reduction in the dose of these medications may be considered to minimize additive sedative effects, if they occur. With hypnotic medications, the risk of next-day psychomotor impairment is increased during co-administration of other CNS depressants, which may decrease the ability to perform tasks requiring full mental alertness such as driving.
Chlorcyclizine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlordiazepoxide: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Chlordiazepoxide; Clidinium: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Chlorpheniramine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Codeine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Dextromethorphan: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Dihydrocodeine; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Guaifenesin; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Hydrocodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Hydrocodone; Phenylephrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpheniramine; Pseudoephedrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Chlorpromazine: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Cisatracurium: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Clemastine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Clevidipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Clomipramine: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Clonazepam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Clorazepate: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Clozapine: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as antipsychotics, can increase CNS depression.
Codeine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants.
Codeine; Guaifenesin: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants.
Codeine; Phenylephrine; Promethazine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants. (Moderate) Because promethazine causes pronounced sedation, an enhanced CNS depressant effect or additive drowsiness may occur when it is combined with other CNS depressants including dantrolene.
Codeine; Promethazine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants. (Moderate) Because promethazine causes pronounced sedation, an enhanced CNS depressant effect or additive drowsiness may occur when it is combined with other CNS depressants including dantrolene.
COMT inhibitors: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including skeletal muscle relaxants, due to the possibility of additive sedation.
Cyclizine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Cyproheptadine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Desipramine: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Deutetrabenazine: (Moderate) Advise patients that concurrent use of deutetrabenazine and drugs that can cause CNS depression, such as dantrolene, may have additive effects and worsen drowsiness or sedation.
Dexchlorpheniramine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Dexmedetomidine: (Moderate) Due to the anesthetic effects of dexmedetomidine, concurrent use with other CNS depressants, such as skeletal muscle relaxants, could result in additive sedative effects and possibly prolong recovery from anesthesia. Dosage adjustments of either or both medications may be necessary.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Dextromethorphan; Promethazine: (Moderate) Because promethazine causes pronounced sedation, an enhanced CNS depressant effect or additive drowsiness may occur when it is combined with other CNS depressants including dantrolene.
Diazepam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Dihydrocodeine; Guaifenesin; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking skeletal muscle relaxants.
Diltiazem: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Dimenhydrinate: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Diphenhydramine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Diphenhydramine; Hydrocodone; Phenylephrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants. (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Diphenhydramine; Ibuprofen: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Diphenhydramine; Naproxen: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Diphenhydramine; Phenylephrine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Doxacurium: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Doxepin: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Doxylamine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Doxylamine; Pyridoxine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Dronabinol: (Moderate) Concomitant use of skeletal muscle relaxants with dronabinol can result in additive CNS depression and dizziness, which can impair the ability to undertake tasks requiring mental alertness. Utilize appropriate caution if these drugs are given together.
Droperidol: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as droperidol, can increase CNS depression.
Enalapril; Felodipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Enflurane: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
Entacapone: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including skeletal muscle relaxants, due to the possibility of additive sedation.
Estazolam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Estrogens: (Moderate) Concomitant use of dantrolene and estrogens may increase the risk of developing hepatotoxicity. While a definite drug interaction with dantrolene and estrogen therapy has not yet been established, caution should be observed if the two drugs are to be given concomitantly. Hepatotoxicity has occurred more often, for example, in women over 35 years of age receiving concomitant estrogen therapy.
Eszopiclone: (Moderate) Simultaneous use of dantrolene and other CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase CNS depression (e.g., drowsiness). A reduction in the dose of these medications may be considered to minimize additive sedative effects, if they occur. With hypnotic medications, the risk of next-day psychomotor impairment is increased during co-administration of other CNS depressants, which may decrease the ability to perform tasks requiring full mental alertness such as driving.
Ethanol: (Moderate) Patients should limit or avoid alcohol during use of dantrolene. Alcohol may have additive effects with dantrolene, which may commonly cause drowsiness and dizziness. Muscle weakness has also been reported following use of dantrolene injection; some of these symptoms may persist for up to 48 hours. Caution should be exercised.
Etomidate: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
Felodipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Fentanyl: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Fluoxetine; Olanzapine: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as antipsychotics, can increase CNS depression.
Fluphenazine: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Flurazepam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Fospropofol: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
General anesthetics: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
Guaifenesin; Hydrocodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Guaifenesin; Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Haloperidol: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as antipsychotics, can increase CNS depression.
Halothane: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
Homatropine; Hydrocodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Hydrocodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Hydrocodone; Ibuprofen: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Hydrocodone; Phenylephrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Hydrocodone; Potassium Guaiacolsulfonate: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Hydrocodone; Potassium Guaiacolsulfonate; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Hydrocodone; Pseudoephedrine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with skeletal muscle relaxants 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 acetaminophen; hydrocodone or hydrocodone; ibuprofen is initiated in a patient taking a skeletal muscle relaxant, reduced initial doses are recommended. If a decision is made to start treatment with hydrocodone extended-release tablets or capsules, initiate hydrocodone at 20% to 30% of the usual dosage. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking skeletal muscle relaxants.
Hydromorphone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 hydromorphone is initiated in a patient taking a skeletal muscle relaxant, use an initial dose of hydromorphone at 1/3 to 1/2 the usual dosage and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Hydroxyzine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Ibuprofen; Oxycodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 oxycodone or oxycodone; naloxone is initiated in a patient taking a skeletal muscle relaxant, use an initial dose of oxycodone at one-third to one-half the usual dosage and titrate to clinical response; reduced initial doses of oxycodone; naltrexone, aspirin, ASA; oxycodone, and ibuprofen; oxycodone are also recommended. If a decision is made to start treatment with acetaminophen; oxycodone extended-release tablets, start with 1 tablet PO every 12 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Imipramine: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Isoflurane: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
Isradipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Kava Kava, Piper methysticum: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants, such as kava kava can result in additive CNS depression. Persons taking other CNS-active medications such as, skeletal muscle relaxants, should discuss the use of herbal supplements with their health care professional prior to consuming kava kava. Patients should not abruptly stop taking their prescribed medications.
Ketamine: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
Levorphanol: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 levorphanol is initiated in a patient taking a skeletal muscle relaxant, reduce the initial dose of levorphanol by approximately 50% or more. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Lofexidine: (Moderate) Monitor for additive sedation during coadministration of lofexidine and dantrolene. Lofexidine can potentiate the effects of CNS depressants. Patients should be advised to avoid driving or performing any other tasks requiring mental alertness until the effects of the combination are known.
Lorazepam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Loxapine: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as antipsychotics, can increase CNS depression.
Maprotiline: (Moderate) Skeletal muscle relaxants should be combined cautiously with cyclic antidepressants like maprotiline because they could cause additive CNS depressant effects. Depending on the specific agent (e.g., cyclobenzaprine, and orphenadrine), additive anticholinergic effects may also be seen. Clinicians should note that antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. Patients should be monitored for excessive adverse effects from either agent.
Meclizine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Mepenzolate: (Moderate) CNS depression can be increased when mepenzolate is combined with other CNS depressants such as skeletal muscle relaxants.
Meperidine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Meperidine; Promethazine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. (Moderate) Because promethazine causes pronounced sedation, an enhanced CNS depressant effect or additive drowsiness may occur when it is combined with other CNS depressants including dantrolene.
Mephobarbital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Meprobamate: (Moderate) Simultaneous use of dantrolene and other CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase CNS depression (e.g., drowsiness). A reduction in the dose of these medications may be considered to minimize additive sedative effects, if they occur. With hypnotic medications, the risk of next-day psychomotor impairment is increased during co-administration of other CNS depressants, which may decrease the ability to perform tasks requiring full mental alertness such as driving.
Mesoridazine: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Methadone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 methadone is initiated in a patient taking a skeletal muscle relaxant, reduced dosages are recommended; in opioid-naive adults, use an initial methadone dose of 2.5 mg PO every 12 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Methohexital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Methotrexate: (Moderate) Concomitant administration of methotrexate and dantrolene may result in elevated methotrexate concentrations. Elevated methotrexate concentrations were noted in a girl who received oral dantrolene a day before intravenous methotrexate 12 g/m2 (18 grams). The methotrexate concentration was 418 micromol/L twenty-four hours after the dose. The threshold value of 0.2 micromol/L was reached 324 hours after the start of the methotrexate infusion despite administration of carboxypeptidase-G2, an enzyme that hydrolyzes methotrexate to nontoxic metabolites, at hours 54 and 78. Three weeks later, a methotrexate dose of 10 grams was well-tolerated with a standard decrease in plasma concentrations. The clearance of methotrexate may have been impaired by dantrolene or the metabolite 5-hydroxydantrolene. Also, altered protein binding may have occurred; both dantrolene and methotrexate bind to albumin.
Methscopolamine: (Moderate) CNS depression can be increased when methscopolamine is combined with other CNS depressants such as skeletal muscle relaxants.
Midazolam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Mirtazapine: (Moderate) Skeletal muscle relaxants like dantrolene may cause additive CNS depression if used concomitantly with other drugs with CNS depressant properties such as mirtazapine. Combination therapy may amplify sedation and dizziness, which can impair the patient's ability to perform tasks requiring mental alertness. Dosage adjustments of either or both medications may be necessary in some instances.
Mivacurium: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Molindone: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as molindone, can increase CNS depression. In addition, antipsychotics are associated with anticholinergic effects; therefore, additive effects may be seen during concurrent use of molindone and other drugs having anticholinergic activity. Clinicians should note that antimuscarinic effects may be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Morphine: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 morphine is initiated in a patient taking a skeletal muscle relaxant, reduced initial dosages are recommended. For extended-release products, start with the lowest possible dose of morphine (i.e., 15 mg PO every 12 hours, extended-release tablets; 30 mg or less PO every 24 hours, extended-release capsules). Use an initial morphine; naltrexone dose of 20 mg/0.8 mg PO every 24 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Morphine; Naltrexone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 morphine is initiated in a patient taking a skeletal muscle relaxant, reduced initial dosages are recommended. For extended-release products, start with the lowest possible dose of morphine (i.e., 15 mg PO every 12 hours, extended-release tablets; 30 mg or less PO every 24 hours, extended-release capsules). Use an initial morphine; naltrexone dose of 20 mg/0.8 mg PO every 24 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Nabilone: (Moderate) Concomitant use of nabilone with other CNS depressants like skeletal muscle relaxants can potentiate the effects of nabilone on respiratory depression, sedation and dizziness, which can impair the ability to undertake tasks requiring mental alertness.
Nalbuphine: (Moderate) Concomitant use of nalbuphine with other CNS depressants, such as skeletal muscle relaxants, can potentiate the effects of nalbuphine on respiratory depression, CNS depression, and sedation.
Neuromuscular blockers: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Nicardipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Nifedipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Nimodipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Nisoldipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Nortriptyline: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Olanzapine: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as antipsychotics, can increase CNS depression.
Oxazepam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Oxycodone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 oxycodone or oxycodone; naloxone is initiated in a patient taking a skeletal muscle relaxant, use an initial dose of oxycodone at one-third to one-half the usual dosage and titrate to clinical response; reduced initial doses of oxycodone; naltrexone, aspirin, ASA; oxycodone, and ibuprofen; oxycodone are also recommended. If a decision is made to start treatment with acetaminophen; oxycodone extended-release tablets, start with 1 tablet PO every 12 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Oxymorphone: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 oxymorphone is initiated in a patient taking a skeletal muscle relaxant, use an initial dose of oxymorphone at one-third to one-half the usual dosage and titrate to clinical response. If the extended-release oxymorphone tablets are used concurrently with a skeletal muscle relaxant, use an initial dosage of 5 mg PO every 12 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Pancuronium: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Pentazocine: (Moderate) Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity. Coadministration of pentazocine with skeletal muscle relaxants may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation.
Pentazocine; Naloxone: (Moderate) Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity. Coadministration of pentazocine with skeletal muscle relaxants may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation.
Pentobarbital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Perindopril; Amlodipine: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Perphenazine: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Perphenazine; Amitriptyline: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression. (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Phenobarbital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Phenothiazines: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Phenylephrine; Promethazine: (Moderate) Because promethazine causes pronounced sedation, an enhanced CNS depressant effect or additive drowsiness may occur when it is combined with other CNS depressants including dantrolene.
Pimozide: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as antipsychotics, can increase CNS depression.
Primidone: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Prochlorperazine: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Promethazine: (Moderate) Because promethazine causes pronounced sedation, an enhanced CNS depressant effect or additive drowsiness may occur when it is combined with other CNS depressants including dantrolene.
Propofol: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
Protriptyline: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Quazepam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Quetiapine: (Moderate) Simultaneous use of dantrolene and other CNS depressants such as antipsychotics can increase CNS depression (e.g., drowsiness).
Rapacuronium: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Remifentanil: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Riluzole: (Moderate) Monitor for signs and symptoms of hepatic injury during coadministration of riluzole and dantrolene. Concomitant use may increase the risk for hepatotoxicity. Discontinue riluzole if clinical signs of liver dysfunction are present.
Risperidone: (Moderate) Simultaneous use of skeletal muscle relaxants and other CNS depressants, such as antipsychotics, can increase CNS depression.
Rocuronium: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Secobarbital: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Sedating H1-blockers: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Sevoflurane: (Moderate) General anesthetics potentiate the effects of other CNS depressants, including skeletal muscle relaxants.
Sodium Oxybate: (Major) Sodium oxybate should not be used in combination with CNS depressant anxiolytics, sedatives, and hypnotics or other sedative CNS depressant drugs. Additive CNS depressant effects may be possible when sodium oxybate is used concurrently with skeletal muscle relaxants.
Succinylcholine: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Sufentanil: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Tapentadol: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 tapentadol is initiated in a patient taking a skeletal muscle relaxant, a reduced initial dosage of tapentadol is recommended. If the extended-release tapentadol tablets are used concurrently with a skeletal muscle relaxant, use an initial tapentadol dose of 50 mg PO every 12 hours. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Temazepam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Thalidomide: (Major) Avoid the concomitant use of thalidomide with other central nervous system depressants such as skeletal muscle relaxants due to the potential for additive sedative effects.
Thiethylperazine: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Thiopental: (Moderate) Additive CNS depression may occur if barbiturates are used concomitantly with skeletal muscle relaxants. Caution should be exercised during concomitant use of skeletal muscle relaxants and barbiturates; dosage reduction of one or both agents may be necessary.
Thioridazine: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Thiothixene: (Moderate) Thiothixene can potentiate the CNS-depressant action of other drugs, such skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Tolcapone: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including skeletal muscle relaxants, due to the possibility of additive sedation.
Tramadol: (Major) Concomitant use of opiate agonists with skeletal muscle relaxants may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with skeletal muscle relaxants 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 an opiate agonist is initiated in a patient taking a skeletal muscle relaxant, use a lower initial dose of the opiate and titrate to clinical response. If a skeletal muscle relaxant is prescribed for a patient taking an opiate agonist, use a lower initial dose of the skeletal muscle relaxant and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Trandolapril; Verapamil: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Trazodone: (Moderate) CNS depressants, such as skeletal muscle relaxants, should be used cautiously in patients receiving trazodone because of additive CNS-depressant effects, including possible respiratory depression or hypotension. A dose reduction of one or both drugs may be warranted.
Triazolam: (Moderate) Concomitant use of skeletal muscle relaxants with benzodiazepines can result in additive CNS depression. The severity of this interaction may be increased when additional CNS depressants are given.
Tricyclic antidepressants: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Trifluoperazine: (Moderate) Phenothiazines can potentiate the CNS-depressant action of other drugs such as skeletal muscle relaxants. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Trimipramine: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Triprolidine: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Tubocurarine: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Vecuronium: (Moderate) Concomitant use of skeletal muscle relaxants with other CNS depressants can result in additive CNS depression. Also, dantrolene may potentiate neuromuscular block.
Verapamil: (Moderate) Concurrent use with skeletal muscle relaxants and antihypertensive agents may result in additive hypotension. Dosage adjustments of the antihypertensive medication may be required.
Zaleplon: (Moderate) Simultaneous use of dantrolene and other CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase CNS depression (e.g., drowsiness). A reduction in the dose of these medications may be considered to minimize additive sedative effects, if they occur. With hypnotic medications, the risk of next-day psychomotor impairment is increased during co-administration of other CNS depressants, which may decrease the ability to perform tasks requiring full mental alertness such as driving.
Ziprasidone: (Moderate) Ziprasidone has the potential to impair cognitive and motor skills. Additive CNS depressant effects are possible when ziprasidone is used concurrently with any CNS depressant, including dantrolene.
Zolpidem: (Moderate) Simultaneous use of dantrolene and other CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase CNS depression (e.g., drowsiness). A reduction in the dose of these medications may be considered to minimize additive sedative effects, if they occur. With hypnotic medications, the risk of next-day psychomotor impairment is increased during co-administration of other CNS depressants, which may decrease the ability to perform tasks requiring full mental alertness such as driving.