Drug Interactions between fenfluramine and tipranavir
This report displays the potential drug interactions for the following 2 drugs:
- fenfluramine
- tipranavir
Interactions between your drugs
fenfluramine tipranavir
Applies to: fenfluramine and tipranavir
ADJUST DOSE: Coadministration with potent inhibitors of CYP450 1A2 or 2D6 may increase the plasma concentrations of fenfluramine. Over 75% of fenfluramine is metabolized to its major active metabolite, norfenfluramine, primarily by CYP450 1A2, 2B6 and 2D6. When a single 0.35 mg/kg dose of fenfluramine oral solution was coadministered with 50 mg once daily fluvoxamine (a potent CYP450 1A2 inhibitor) at steady state in healthy volunteers, fenfluramine peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 22% and 102%, respectively, while the Cmax and AUC of norfenfluramine decreased by 44% and 22%, respectively. Coadministration with 30 mg once daily paroxetine (a potent CYP450 2D6 inhibitor) at steady state in healthy volunteers increased the Cmax and AUC of fenfluramine by 13% and 81%, respectively, and decreased Cmax and AUC of norfenfluramine by 29% and 13%, respectively. Elevated plasma levels of fenfluramine may increase the risk of serious adverse effects such as valvular heart disease, pulmonary arterial hypertension, blood pressure increases, and serotonin syndrome.
MANAGEMENT: When coadministered with a potent CYP450 1A2 or 2D6 inhibitor, the manufacturer recommends limiting fenfluramine to a maximum total daily dosage of 20 mg without concomitant stiripentol and 17 mg with concomitant stiripentol. If a potent CYP450 1A2 or 2D6 inhibitor is discontinued during maintenance treatment with fenfluramine, consider a gradual increase to the fenfluramine dosage normally recommended without inhibitors, but not to exceed the maximum daily dosage of fenfluramine specified in the product labeling.
References (2)
- (2020) "Product Information. Fintepla (fenfluramine)." Zogenix, Inc
- (2023) "Product Information. Fintepla (fenfluramine)." UCB Pharma Ltd, SUPPL-13
Drug and food interactions
fenfluramine food
Applies to: fenfluramine
GENERALLY AVOID: Alcohol may potentiate the central nervous system and cardiovascular effects of centrally-acting appetite suppressants. In one study, concurrent administration of methamphetamine (30 mg intravenously) and ethanol (1 gm/kg orally over 30 minutes) increased heart rate by 24 beats/minute compared to methamphetamine alone. This increases cardiac work and myocardial oxygen consumption, which may lead to more adverse cardiovascular effects than either agent alone. Subjective effects of ethanol were diminished in the eight study subjects, but those of methamphetamine were not affected. The pharmacokinetics of methamphetamine were also unaffected except for a decrease in the apparent volume of distribution at steady state.
MANAGEMENT: Concomitant use of centrally-acting appetite suppressants and alcohol should be avoided if possible, especially in patients with a history of cardiovascular disease. Patients should be counselled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.
References (3)
- Mendelson J, Jones RT, Upton R, Jacob P 3rd (1995) "Methamphetamine and ethanol interactions in humans." Clin Pharmacol Ther, 57, p. 559-68
- (2001) "Product Information. Didrex (benzphetamine)." Pharmacia and Upjohn
- (2012) "Product Information. Suprenza (phentermine)." Akrimax Pharmaceuticals
tipranavir food
Applies to: tipranavir
ADJUST DOSING INTERVAL: Food does not appear to substantially alter the pharmacokinetics of tipranavir. When tipranavir capsules or oral solution was coadministered with ritonavir capsules at steady-state, no clinically significant changes in tipranavir peak plasma concentration (Cmax) and systemic exposure (AUC) were observed under fed conditions (500 to 682 kcal, 23% to 25% calories from fat) relative to fasted conditions. The effect of food on tipranavir exposure during coadministration with ritonavir tablets has not been evaluated. High-fat foods may enhance the gastrointestinal absorption of tipranavir. In a multiple-dose study, administration of tipranavir capsules with a high-fat meal (868 kcal, 53% from fat, 31% from carbohydrates) increased the oral bioavailability of tipranavir by 31% compared to administration with toast and skimmed milk, but did not significantly affect tipranavir Cmax. Thus, tipranavir may be safely taken with standard or high-fat meals.
MANAGEMENT: Tipranavir coadministered with low-dose ritonavir should be taken with food to improve the gastrointestinal tolerability of ritonavir. According to the product labeling, tipranavir coadministered with ritonavir capsules or solution can be taken with or without meals, whereas tipranavir coadministered with ritonavir tablets must be taken with meals.
References (4)
- (2005) "Product Information. Aptivus (tipranavir)." Boehringer-Ingelheim
- Cerner Multum, Inc. "UK Summary of Product Characteristics."
- Canadian Pharmacists Association (2006) e-CPS. http://www.pharmacists.ca/function/Subscriptions/ecps.cfm?link=eCPS_quikLink
- Cerner Multum, Inc. "Australian Product Information."
Therapeutic duplication warnings
No warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
See also
Drug Interaction Classification
Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
No interaction information available. |
Further information
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