Drug Interactions between amprenavir and deferasirox
This report displays the potential drug interactions for the following 2 drugs:
- amprenavir
- deferasirox
Interactions between your drugs
amprenavir deferasirox
Applies to: amprenavir and deferasirox
MONITOR: Coadministration with deferasirox may decrease the plasma concentrations of drugs that are substrates of the CYP450 3A4 isoenzyme. The mechanism may involve induction of CYP450 3A4 activity by deferasirox, although in vitro, the drug has been shown to inhibit CYP450 3A4. In healthy volunteers, administration of the CYP450 3A4 probe substrate midazolam in combination with deferasirox resulted in a reduction of midazolam peak concentration by 23% and systemic exposure by 17%. In the clinical setting, this effect may be more pronounced.
MANAGEMENT: Caution is advised if deferasirox must be used concomitantly with medications that undergo metabolism by CYP450 3A4, particularly those with a narrow therapeutic range. Dosage adjustments as well as clinical and laboratory monitoring may be appropriate for some drugs whenever deferasirox is added to or withdrawn from therapy.
References
- (2005) "Product Information. Exjade (deferasirox)." Novartis Pharmaceuticals
- Skerjanec A, Wang J, Maren K, Rojkjaer L (2010) "Investigation of the pharmacokinetic interactions of deferasirox, a once-daily oral iron chelator, with midazolam, rifampin, and repaglinide in healthy volunteers." J Clin Pharmacol, 50, p. 205-13
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
deferasirox food
Applies to: deferasirox
ADJUST DOSING INTERVAL: According to product labeling, the bioavailability of deferasirox was variably increased when taken with a meal.
MANAGEMENT: To ensure consistent plasma drug levels, deferasirox should be taken on an empty stomach 30 minutes before eating preferably at the same time everyday.
References
- (2005) "Product Information. Exjade (deferasirox)." Novartis Pharmaceuticals
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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