Drug Interactions between amprenavir and fosamprenavir
This report displays the potential drug interactions for the following 2 drugs:
- amprenavir
- fosamprenavir
Interactions between your drugs
No interactions were found between amprenavir and fosamprenavir. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.
amprenavir
A total of 513 drugs are known to interact with amprenavir.
- Amprenavir is in the drug class protease inhibitors.
- Amprenavir is used to treat HIV Infection.
fosamprenavir
A total of 489 drugs are known to interact with fosamprenavir.
- Fosamprenavir is in the drug class protease inhibitors.
- Fosamprenavir is used to treat the following conditions:
Drug and food interactions
amprenavir food
Applies to: amprenavir
GENERALLY AVOID: Administration with a high-fat meal may decrease the oral bioavailability of amprenavir. The mechanism is unknown. In healthy volunteers, consumption of a standardized high-fat meal decreased the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of amprenavir (1200 mg single oral dose) by 36% and 21%, respectively, compared to administration in the fasted state. The time to reach Cmax (Tmax) was increased 44% following a high-fat meal.
Grapefruit juice does not appear to significantly affect the pharmacokinetics of amprenavir. In 12 healthy volunteers, administration with grapefruit juice (200 mL) decreased the mean peak plasma concentration (Cmax) of amprenavir (1200 mg single oral dose) by 22% compared to water. The median time to reach Cmax (Tmax) was prolonged from 0.75 to 1.13 hours. These pharmacokinetic changes are not thought to be clinically significant, since antiretroviral response is more closely associated with systemic exposure (AUC) and trough plasma concentration (Cmin), which were not affected in the study.
MANAGEMENT: Amprenavir may be taken with or without food, but should not be taken with a high-fat meal.
References
- (2001) "Product Information. Agenerase (amprenavir)." Glaxo Wellcome
- Demarles D, Gillotin C, Bonaventure-Paci S, Vincent I, Fosse S, Taburet AM (2002) "Single-dose pharmacokinetics of amprenavir coadministered with grapefruit juice." Antimicrob Agents Chemother, 46, p. 1589-1590
fosamprenavir food
Applies to: fosamprenavir
ADJUST DOSING INTERVAL: Food may reduce the systemic bioavailability of amprenavir from fosamprenavir oral suspension. The mechanism of interaction has not been described. According to the product labeling, administration of fosamprenavir oral suspension (1400 mg single dose) with a high-fat meal (967 kcal, 67 g fat, 33 g protein, 58 g carbohydrate) reduced amprenavir peak plasma concentration (Cmax) by 46% and systemic exposure (AUC) by 28% compared to administration in a fasted state. The time to reach peak plasma level (Tmax) was delayed by 0.72 hours. In contrast, the same high-fat meal did not affect the pharmacokinetics of amprenavir from fosamprenavir tablets.
MANAGEMENT: Fosamprenavir suspension should be administered on an empty stomach in adults, but with food in pediatric patients to aid palatability and compliance. If emesis occurs within 30 minutes after dosing the suspension, the dose should be repeated. Fosamprenavir tablets may be taken with or without food.
References
- (2003) "Product Information. Lexiva (fosamprenavir)." GlaxoSmithKline
Therapeutic duplication warnings
Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.
Protease inhibitors
Therapeutic duplication
The recommended maximum number of medicines in the 'protease inhibitors' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'protease inhibitors' category:
- amprenavir
- fosamprenavir
Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.
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
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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