Xenical

Lipase Inhibitors for Obesity

Oral Administration

Administer with each main meal containing fat; can be administered up to 1 hour after the meal. Patients should be on a reduced-calorie diet with approximately 30% of the calories from fat. Protein, carbohydrate, and fat intake should be balanced over 3 main meals.
May omit a dose when a meal is missed or if a meal contains no fat.
Orlistat decreases the absorption of some fat-soluble vitamins (A, D, E, K) and beta-carotene. To ensure adequate nutrition, patients should take a daily multivitamin supplement that contains these fat-soluble vitamins. Administer the multivitamin at least 2 hours before or after the administration of orlistat. For example, have the patient take the multivitamin once per day at bedtime unless otherwise directed by the prescriber.

Severe

angioedema / Rapid / Incidence not known
anaphylactoid reactions / Rapid / Incidence not known
vasculitis / Delayed / Incidence not known
bronchospasm / Rapid / Incidence not known
hepatic necrosis / Delayed / Incidence not known
hepatic failure / Delayed / Incidence not known
pancreatitis / Delayed / Incidence not known
seizures / Delayed / Incidence not known

Moderate

fecal incontinence / Early / 1.8-7.7
depression / Delayed / 3.4-3.4
cholelithiasis / Delayed / 2.9-2.9
edema / Delayed / 2.8-2.8
vaginitis / Delayed / 2.6-2.6
bullous rash / Early / Incidence not known
elevated hepatic enzymes / Delayed / Incidence not known
hepatitis / Delayed / Incidence not known
hypoglycemia / Early / Incidence not known
hypothyroidism / Delayed / Incidence not known
vitamin D deficiency / Delayed / Incidence not known
hyperoxaluria / Delayed / Incidence not known

Mild

infection / Delayed / 46.0-46.0
headache / Early / 31.0-31.0
abdominal pain / Early / 25.5-25.5
flatulence / Early / 4.4-23.9
fecal urgency / Early / 2.8-22.1
steatorrhea / Delayed / 6.0-20.0
back pain / Delayed / 13.9-13.9
increased defecation / Early / 2.6-10.8
menstrual irregularity / Delayed / 9.8-9.8
nausea / Early / 8.1-8.1
fatigue / Early / 7.2-7.2
diarrhea / Early / 5.3-5.3
dizziness / Early / 5.2-5.2
rash / Early / 4.3-4.3
myalgia / Early / 4.2-4.2
vomiting / Early / 3.1-3.1
anxiety / Delayed / 2.8-2.8
musculoskeletal pain / Early / Incidence not known
hypovitaminosis / Delayed / Incidence not known
pruritus / Rapid / Incidence not known
purpura / Delayed / Incidence not known
urticaria / Rapid / Incidence not known
maculopapular rash / Early / Incidence not known

alli, Xenical

Rx, OTC

Gastrointestinal lipase inhibitor; non-systemically blocks dietary fat absorption; causes weight loss and limits weight regain; significant GI side effects
By prescription, indicated for obese adults and adolescents 12 years and older with a BMI 30 kg/m2 or more OR those with a BMI of 27 kg/m2 or more with 1 or more obesity-related risk factors
Non-prescription product used to help promote weight loss in overweight adults

For the treatment of obesity and for chronic weight management as an adjunct to reduced-calorie diet and lifestyle modifications.
NOTE: Orlistat is indicated in persons with an initial body mass index (BMI) of 30 kg/m2 or more or 27 kg/m2 or more in the presence of other risk factors (e.g., hypertension, diabetes mellitus, or dyslipidemia).[27971]
Oral dosage (orlistat 120 mg capsules, e.g., Xenical) Adults

120 mg PO 3 times daily with each main meal containing fat. May omit dose if a meal is occasionally missed or contains no fat. The patient should be on a nutritionally balanced, reduced-calorie diet that includes approximately 30% of calories from fat. The daily intake of fat, carbohydrate, and protein should be distributed over 3 main meals.[27971] When used under optimal conditions, orlistat can reduce BMI and weight, and reduces the risk for weight regain in chronic use. Pharmacotherapy should be offered as chronic treatment along with lifestyle modifications to persons affected by obesity when the potential benefits outweigh the risks. Short-term pharmacotherapy has not been shown to produce longer-term health benefits and cannot be generally recommended.

Children and Adolescents 12 to 17 years

120 mg PO 3 times daily with each main meal containing fat. May omit dose if a meal is occasionally missed or contains no fat. The patient should be on a nutritionally balanced, reduced-calorie diet that includes approximately 30% of calories from fat. The daily intake of fat, carbohydrate, and protein should be distributed over 3 main meals.[27971] When used under optimal conditions, orlistat can reduce BMI and weight, and reduces the risk for weight regain in chronic use; however, in pediatric patients, adherence at meal (e.g., school days) may be problematic.  Pharmacotherapy is usually reserved for pediatric patients with a BMI at the 95th percentile or more or meeting the adult BMI recommendations for use. Reserve pharmacotherapy for overweight children (BMI 85th to 94th percentile) for those with significant, severe comorbidities who have not responded to lifestyle modification.

Oral dosage (OTC orlistat 60 mg capsules, e.g., Alli) Adults

60 mg PO 3 times daily with each main meal containing fat. May omit dose if a meal is occasionally missed or contains no fat. Max: 180 mg/day.[60877] When used under optimal conditions, orlistat can reduce BMI and weight, and reduces the risk for weight regain in chronic use. Pharmacotherapy should be offered as chronic treatment along with lifestyle modifications to persons affected by obesity when the potential benefits outweigh the risks. Short-term pharmacotherapy has not been shown to produce longer-term health benefits and cannot be generally recommended.

Hepatic Impairment

No dosage adjustments are needed. During treatment, if signs or symptoms of liver injury occur, discontinue treatment. Some guidelines suggest avoidance of orlistat and other weight-loss medications in patients with severe hepatic disease.

Renal Impairment

No dosage adjustments are needed.

Abacavir: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Abacavir; Dolutegravir; Lamivudine: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Abacavir; Lamivudine, 3TC: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Acitretin: (Moderate) Due the effect of orlistat on fat absorption and the lower serum levels of fat-soluble vitamins noted during clinical trials, the bioavailability of acitretin may be decreased. Close monitoring of patients receiving acitretin with orlistat is recommended.
Alogliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Alogliptin; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Alogliptin; Pioglitazone: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Alpha-glucosidase Inhibitors: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Amiodarone: (Major) In one pharmacokinetic study of healthy volunteers, administration of orlistat 120 mg three times daily for 13 days and a single orlistat dose of 120 mg on the morning of Day 14 in addition to a single dose of 1200 mg amiodarone on Day 4 resulted in a 23% to 27% reduction in the systemic exposure to amiodarone and its metabolite desethylamiodarone. The effect of initiating treatment with orlistat in patients stable on amiodarone therapy has not been studied; however, a reduced therapeutic effect of amiodarone is possible. The clinical response to amiodarone should be monitored closely if orlistat is initiated during chronic amiodarone therapy.
Apixaban: (Moderate) Patients on chronic stable doses of anticoagulants, like apixaban, should be monitored closely for changes in coagulation parameters when orlistat is prescribed. Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Atazanavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Atazanavir; Cobicistat: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Bexarotene: (Moderate) Due the effect of orlistat on fat absorption and the lower serum levels of fat-soluble vitamins noted during clinical trials, the bioavailability of orally administered retinoids, such as bexarotene may also be decreased.
Bictegravir; Emtricitabine; Tenofovir Alafenamide: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Canagliflozin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Canagliflozin; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Cranberry, Vaccinium macrocarpon Ait.: (Moderate) Administer vitamin E at least 2 hours before or after the administration of orlistat to limit effects on oral absorption. Orlistat has been shown to inhibit the absorption of a vitamin E acetate supplement by 60%.
Cyclosporine: (Major) Orlistat decreases the absorption of fat by inhibiting gastrointestinal lipases and as cyclosporine is dependent on lipid absorption, especially the Sandimmune formulation, the absorption of cyclosporine is inhibited. Caution is advised with the concomitant use of orlistat and cyclosporine therapy. More frequent cyclosporine concentration monitoring may be needed. To reduce the chance of a drug-drug interaction, cyclosporine should be administered at least 2 hours before or after orlistat in patients taking both drugs; although, as noted, separation of administration times may not always alter the course of the interaction.
Dabigatran: (Moderate) Patients on chronic stable doses of anticoagulants, like dabigatran, should be monitored closely for changes in coagulation parameters when orlistat is prescribed. Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Dalteparin: (Moderate) Patients on chronic stable doses of anticoagulants, like dalteparin, should be monitored closely for changes in coagulation parameters when orlistat is prescribed. Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Dapagliflozin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Dapagliflozin; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Dapagliflozin; Saxagliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Darunavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Darunavir; Cobicistat: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Delavirdine: (Major) Monitor HIV RNA concentrations frequently during concurrent use of orlistat and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Discontinue orlistat if an increased HIV viral load is confirmed. Loss of virological control has been reported in persons with HIV infection taking orlistat with antiretrovirals, including NNRTIs. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the antiretroviral agent.
Didanosine, ddI: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Dipeptidyl Peptidase-4 Inhibitors: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Dolutegravir; Lamivudine: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Doravirine; Lamivudine; Tenofovir disoproxil fumarate: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Dulaglutide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Edoxaban: (Moderate) Patients on chronic stable doses of anticoagulants like edoxaban should be monitored closely for changes in coagulation parameters when orlistat is prescribed. Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Efavirenz: (Major) Monitor HIV RNA concentrations frequently during concurrent use of orlistat and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Discontinue orlistat if an increased HIV viral load is confirmed. Loss of virological control has been reported in persons with HIV infection taking orlistat with antiretrovirals, including NNRTIs. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the antiretroviral agent.
Efavirenz; Emtricitabine; Tenofovir Disoproxil Fumarate: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Major) Monitor HIV RNA concentrations frequently during concurrent use of orlistat and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Discontinue orlistat if an increased HIV viral load is confirmed. Loss of virological control has been reported in persons with HIV infection taking orlistat with antiretrovirals, including NNRTIs. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the antiretroviral agent. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Major) Monitor HIV RNA concentrations frequently during concurrent use of orlistat and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Discontinue orlistat if an increased HIV viral load is confirmed. Loss of virological control has been reported in persons with HIV infection taking orlistat with antiretrovirals, including NNRTIs. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the antiretroviral agent. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Empagliflozin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Empagliflozin; Linagliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Empagliflozin; Linagliptin; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Empagliflozin; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Emtricitabine: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Emtricitabine; Rilpivirine; Tenofovir alafenamide: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Emtricitabine; Rilpivirine; Tenofovir Disoproxil Fumarate: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Emtricitabine; Tenofovir alafenamide: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Emtricitabine; Tenofovir Disoproxil Fumarate: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Enoxaparin: (Moderate) Patients on chronic stable doses of anticoagulants, like enoxaparin, should be monitored closely for changes in coagulation parameters when orlistat is prescribed. Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Entecavir: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Ertugliflozin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Ertugliflozin; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Ertugliflozin; Sitagliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Etravirine: (Major) Monitor HIV RNA concentrations frequently during concurrent use of orlistat and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Discontinue orlistat if an increased HIV viral load is confirmed. Loss of virological control has been reported in persons with HIV infection taking orlistat with antiretrovirals, including NNRTIs. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the antiretroviral agent.
Exenatide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Fish Oil, Omega-3 Fatty Acids (Dietary Supplements): (Moderate) Administer vitamin E at least 2 hours before or after the administration of orlistat to limit effects on oral absorption. Orlistat has been shown to inhibit the absorption of a vitamin E acetate supplement by 60%.
Fondaparinux: (Moderate) Patients on chronic stable doses of anticoagulants, like fondaparinux, should be monitored closely for changes in coagulation parameters when orlistat is prescribed. Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Fosamprenavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Glipizide; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Glyburide; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Heparin: (Moderate) Patients on chronic stable doses of anticoagulants, like heparin, should be monitored closely for changes in coagulation parameters when orlistat is prescribed. Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Incretin Mimetics: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Indinavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Insulin Degludec; Liraglutide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Insulin Glargine; Lixisenatide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Insulins: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of insulins or other medicines for diabetes may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Isotretinoin: (Moderate) The bioavailability of orally administered retinoids may be decreased during coadministration with isotretinoin. In patients receiving orally-administered retinoids along with orlistat, close monitoring is recommended. In addition, the manufacturer recommends that fat-soluble vitamin analogues be administered at least 2 hours before or after the administration of orlistat to limit effects on oral absorption.
Lamivudine, 3TC: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Lamivudine; Tenofovir Disoproxil Fumarate: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued. (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Levothyroxine: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of orlistat. Concurrent use may reduce the efficacy of thyroid hormones by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Monitor TSH while orlistat is used concurrently. Hypothyroidism has been reported in patients treated concomitantly with orlistat and levothyroxine postmarketing.
Levothyroxine; Liothyronine (Porcine): (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of orlistat. Concurrent use may reduce the efficacy of thyroid hormones by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Monitor TSH while orlistat is used concurrently. Hypothyroidism has been reported in patients treated concomitantly with orlistat and levothyroxine postmarketing.
Levothyroxine; Liothyronine (Synthetic): (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of orlistat. Concurrent use may reduce the efficacy of thyroid hormones by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Monitor TSH while orlistat is used concurrently. Hypothyroidism has been reported in patients treated concomitantly with orlistat and levothyroxine postmarketing.
Linagliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Linagliptin; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Liothyronine: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of orlistat. Concurrent use may reduce the efficacy of thyroid hormones by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Monitor TSH while orlistat is used concurrently. Hypothyroidism has been reported in patients treated concomitantly with orlistat and levothyroxine postmarketing.
Liraglutide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Lixisenatide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Lopinavir; Ritonavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Lorcaserin: (Moderate) The safety and efficacy of coadministration of lorcaserin with other products intended for weight loss including prescription drugs (e.g., phentermine, fenfluramine, dexfenfluramine, orlistat, phendimetrazine, amphetamines), over-the-counter drugs (e.g., orlistat, phenylpropanolamine, ephedrine), and herbal preparations (ephedra, Ma huang) have not been established. Some of these agents (fenfluramine, dexfenfluramine) are known to increase the risk for cardiac valvulopathy and pulmonary hypertension. Co-use of sibutramine with other serotonergic medications is contraindicated due to the risk for serotonin-related adverse effects, such as serotonin syndrome.
Meglitinides: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Metformin; Repaglinide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Metformin; Rosiglitazone: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Metformin; Saxagliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Metformin; Sitagliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Nelfinavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Nevirapine: (Major) Monitor HIV RNA concentrations frequently during concurrent use of orlistat and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Discontinue orlistat if an increased HIV viral load is confirmed. Loss of virological control has been reported in persons with HIV infection taking orlistat with antiretrovirals, including NNRTIs. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the antiretroviral agent.
Nirmatrelvir; Ritonavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Non-nucleoside reverse transcriptase inhibitors: (Major) Monitor HIV RNA concentrations frequently during concurrent use of orlistat and non-nucleoside reverse transcriptase inhibitors (NNRTIs). Discontinue orlistat if an increased HIV viral load is confirmed. Loss of virological control has been reported in persons with HIV infection taking orlistat with antiretrovirals, including NNRTIs. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the antiretroviral agent.
Nucleoside reverse transcriptase inhibitors: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Phentermine: (Moderate) The safety and efficacy of coadministration of phentermine with other products intended for weight loss has not been established.
Phentermine; Topiramate: (Moderate) The safety and efficacy of coadministration of phentermine with other products intended for weight loss has not been established.
Phytonadione, Vitamin K1: (Moderate) Several drugs can interfere with the oral bioavailability of vitamin K including orlistat. In patients receiving orlistat routinely for a prolonged period of time (i.e., more than 2 weeks), vitamin K intake may need to be increased.
Pioglitazone: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Pioglitazone; Glimepiride: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Pioglitazone; Metformin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Pramlintide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of pramlintide or other medicines for diabetes may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Pravastatin: (Moderate) Serum concentrations of pravastatin increased by approximately 30% when administered with orlistat in a parallel study of 24 normal-weight, mildly hypercholesterolemic subjects. Orlistat produced additive lipid-lowering effects when used concomittantly with pravastatin. However, another study failed to show any changes in pravastatin pharmacokinetics when coadministered with orlistat. Use caution and monitor patients carefully if using these drugs together.
Propafenone: (Major) Orlistat may limit the fraction of propafenone available for absorption. In post-marketing reports, abrupt cessation of orlistat in patients stabilized on propafenone therapy has resulted in severe adverse events including convulsions, AV block and acute circulatory failure.
Protease inhibitors: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Ritonavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Rivaroxaban: (Moderate) Patients on chronic stable doses of anticoagulants like rivaroxaban should be monitored closely for changes in coagulation parameters when orlistat is prescribed. Reports of decreased prothrombin, increased INR, and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants.
Rosiglitazone: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Saquinavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Saxagliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Semaglutide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
SGLT2 Inhibitors: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Sitagliptin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Sotagliflozin: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Stavudine, d4T: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not

known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Sulfonylureas: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Tenofovir Alafenamide: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Tenofovir Alafenamide: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Tenofovir Disoproxil Fumarate: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with tenofovir, PMPA. Loss of virological control has been reported in HIV-infected patients taking orlistat with tenofovir disoproxil fumarate and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Thiazolidinediones: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Thyroid hormones: (Moderate) Oral thyroid hormones should be administered at least 4 hours before or after a dose of orlistat. Concurrent use may reduce the efficacy of thyroid hormones by binding and delaying or preventing oral absorption, potentially resulting in hypothyroidism. Monitor TSH while orlistat is used concurrently. Hypothyroidism has been reported in patients treated concomitantly with orlistat and levothyroxine postmarketing.
Tipranavir: (Major) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral protease inhibitors. Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.
Tirzepatide: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
Tretinoin, ATRA: (Moderate) The bioavailability of orally administered retinoids may be decreased if coadministered with orlistat. In patients receiving orally-administered retinoids along with orlistat, close monitoring is recommended. In addition, the manufacturer recommends that fat-soluble vitamin analogues be administered at least 2 hours before or after the administration of orlistat to limit effects on oral absorption.
Triheptanoin: (Major) Avoid coadministration of triheptanoin with orlistat. Coadministration with a pancreatic lipase inhibitor, such as orlistat, may reduce exposure to the triheptanoin metabolite, heptanoate, and reduce the efficacy of triheptanoin.
Vitamin A: (Moderate) Due to orlistat's mechanism of action, the potential exists for the malabsorption of drugs and dietary supplements. Patients should be advised to take a multivitamin supplement once per day that contains fat soluble vitamins A, D, E, K and beta-carotene. The manufacturer recommends that fat-soluble vitamin supplements be administered at least 2 hours before or after the administration of orlistat to limit effects on oral absorption.
Vitamin D analogs: (Moderate) Orlistat reduced the absorption of fat-soluble vitamins absorption during clinical trials. The bioavailability of orally administered vitamin D analogs may also be decreased. In patients receiving orally-administered vitamin D analogs along with orlistat, close monitoring is recommended. In addition, the manufacturer recommends that fat-soluble vitamin analogs be administered at least 2 hours before or after the administration of orlistat to limit effects on oral absorption.
Vitamin D: (Moderate) Administer vitamin E at least 2 hours before or after the administration of orlistat to limit effects on oral absorption. Orlistat has been shown to inhibit the absorption of a vitamin E acetate supplement by 60%.
Vitamin D: (Moderate) Orlistat reduced the absorption of fat-soluble vitamins during clinical trials. The bioavailability of orally administered vitamin D may also be decreased. In patients receiving orally-administered vitamin D with orlistat, close monitoring is recommended. In addition, the manufacturer recommends that fat-soluble vitamins be administered at least 2 hours before or after the administration of orlistat to limit effects on oral absorption.
Vitamin E: (Moderate) Administer vitamin E at least 2 hours before or after the administration of orlistat to limit effects on oral absorption. Orlistat has been shown to inhibit the absorption of a vitamin E acetate supplement by 60%.
Vitamin E: (Moderate) Administer vitamin E at least 2 hours before or after the administration of orlistat to limit effects on oral absorption. Orlistat has been shown to inhibit the absorption of a vitamin E acetate supplement by 60%.
Warfarin: (Moderate) Warfarin therapy can be affected by changes in dietary intake of vitamin K. Since vitamin K absorption may be affected by orlistat, patients on chronic stable doses of warfarin should be monitored closely for changes in coagulation parameters when orlistat is prescribed; some experts recommend that the INR be monitored weekly during the first month of orlistat therapy. Reports of decreased prothrombin, increased INR and unbalanced anticoagulant treatment resulting in change of hemostatic parameters have been reported in patients treated concomitantly with orlistat and anticoagulants. Orlistat 120 mg PO 3 times per day administered orally for 16 days in 12 normal-weight subjects did not appear to alter vitamin K nutritional status. No changes in the pharmacokinetics or pharmacodynamics (PT and serum Factor VII) of warfarin were noted following a single 30 mg dose of warfarin in a placebo-controlled, randomized, third-party blind, 2-way crossover study. However, vitamin K levels decreased.
Zidovudine, ZDV: (Moderate) According to the manufacturer of orlistat, HIV RNA levels should be frequently monitored in patients receiving orlistat while being treated for HIV infection with anti-retroviral nucleoside reverse transcriptase inhibitors (NRTIs). Loss of virological control has been reported in HIV-infected patients taking orlistat with atazanavir, ritonavir, tenofovir disoproxil fumarate, emtricitabine, lopinavir; ritonavir, and emtricitabine; efavirenz; tenofovir disoproxil fumarate. The exact mechanism for this interaction is not known, but may involve inhibition of systemic absorption of the anti-retroviral agent. If an increased HIV viral load is confirmed, orlistat should be discontinued.

alli/Orlistat/Xenical Oral Cap: 60mg, 120mg

Adults

360 mg/day PO (Xenical, Rx-only), 180 mg/day PO (Alli, OTC use).

Geriatric

360 mg/day PO (Xenical, Rx-only), 180 mg/day PO (Alli, OTC use).

Adolescents

360 mg/day PO (e.g., Xenical, Rx-only); OTC use (e.g., Alli) not recommended.

Children

12 years: 360 mg/day PO (Xenical, Rx-only); OTC use (i.e., Alli) not recommended.
1 to 11 years: Safety and efficacy have not been established.

Infants

Not indicated.

Orlistat produces weight loss through inhibition of nutrient absorption. A covalent bond is formed with the active serine residue site of gastric and pancreatic lipases within the lumen of the stomach and the small intestine. As these enzymes become unavailable to hydrolyze dietary triglycerides into free fatty acids and monoglycerides, less fat is absorbed by the body. This results in decreased caloric intake that may result in negative energy balance and weight loss. Therefore, systemic absorption of the drug is not needed to produce a weight-lowering effect. At the recommended therapeutic dose of 120 mg orlistat PO three times per day, dietary fat absorption is inhibited by approximately 30%. Because orlistat may reduce the absorption of fat-soluble vitamins A, D, E, K, and beta-carotene, it is recommended patients take a daily multivitamin containing these vitamins during therapy, with the multivitamin supplement taken at least 2 hours before or after the administration orlistat.

Orlistat is administered orally and has minimal systemic absorption. Sporadic intact amounts of orlistat, low plasma concentration levels (<10 ng/ml), and no evidence of accumulation were observed during therapeutic studies. In vitro, orlistat was > 99% bound to plasma proteins (primarily lipoproteins and albumin) with minimal partitioning into erythrocytes. Metabolism of orlistat to weakly active and inactive metabolites is believed to occur mainly within the gastrointestinal wall. Approximately 83% of a single oral dose of orlistat was excreted unchanged in the feces. Renal excretion was < 2% of the dose. Complete excretion of both urinary and fecal orlistat was reached in 3 to 5 days. The estimated half-life of the absorbed portion of orlistat was approximately 1 to 2 hours.

Oral Route

Peak plasma concentrations of orlistat (<5 ng/ml) occurred approximately 8 hours after a 360 mg dose. Based on fecal fat measurements, the effect of orlistat may be seen within 24 to 48 hours.

Pregnancy

Orlistat is contraindicated for use during pregnancy because weight loss offers no potential benefit to a pregnant woman and weight loss, coupled with reduced absorption of fat-soluble vitamins (A, D, E, K) may result in fetal harm. A minimum weight gain and no weight loss is currently recommended for all pregnant women, including those who are already overweight or obese, due to the obligatory weight gain that occurs in maternal tissues during pregnancy and the need to provide appropriate nutrition to the developing fetus. No embryotoxicity or teratogenicity was seen in animals that received orlistat at doses much higher than the recommended human dose. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard of maternal weight loss to the fetus.[27971] Pregnant women must also avoid nonprescription use of the drug.[60877] According to the American Association of Clinical Endocrinologists and American College of Endocrinology (AACE/ACE) Obesity Clinical Practice Guidelines, weight loss medications must not be used during pregnancy. The AACE/ACE Obesity Guidelines recommend that women of childbearing potential receiving orlistat use adequate contraception and discontinue orlistat if pregnancy occurs.[62881]

The manufacturer recommends caution when administering orlistat to a breast-feeding woman; nonprescription use should be avoided. The minimal systemic bioavailability of orlistat suggests that the drug is not expressed in breast milk; however, it is not known with certainty if orlistat is present in human milk.[27971] [60877] It is not known if the effects of orlistat on maternal availability of fat-soluble vitamins would affect breast milk quality or quantity. Women who are breast-feeding should be encouraged to take proper vitamin supplementation as suggested by orlistat product labeling to avoid deficiencies of fat-soluble vitamins. According to the American Association of Clinical Endocrinologists and American College of Endocrinology (AACE/ACE) Obesity Clinical Practice Guidelines, the use of orlistat in breast-feeding women is generally not recommended.[62881]