Fact Sheets on Antiretroviral Drugs

<strong>Fact</strong> <strong>Sheets</strong> on Antiretroviral Drugs
Half-life in plasma
From 7.1 to 10.6 hours
Metabolism
Mainly in the liver
Warning
Because of the potential risk of toxicity from the large amount of the excipient
propylene glycol, Amprenavir oral solution is contraindicated in infants and children
below the age of four years, pregnant women, patients with hepatic or renal failure.
Certain ethnic populations, such as Asians, Eskimos, and Native Americans, may be at
increased risk of propylene glycol-associated adverse events because of alcohol
dehydrogenase polymorphisms; however, no data are available on propylene glycol
metabolism in these groups.
Interactions with other drugs
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� Yes; inhibition of CYP3A4 (Cytochrome P450 3A4 isoform)
� If Didanosine or antacids are administered, they should be taken at least
one hour apart.
� Contraindicated drugs (APV not to be taken with these drugs): Astemizole;
Bepridil; Cisapride; Ergotamine and similar alkaloids; Garlic supplements;
Lovastatin; Midazolam; Pimozide, Rifampicin; St. John’s wort (hypericum
perforatum); Simvastatin; Terfenadine and Triazolam.
� Because of the large amount of the excipient propylene glycol, Amprenavir
oral solution should not be co-administered with Disulfiram or
Metronidazole or some cephalosporins, such as Cefamandole or
Cefoperazone.
� Amprenavir levels are increased by Abacavir (§APV); Delavirdine;
Clarithromycin; Indinavir; Ketoconazole; Lopinavir; Nelfinavir; §Ritonavir
(§APV) and Zidovudine.
� Amprenavir levels are decreased by Dexamethasone; Efavirenz (§APV);
§Lopinavir (§APV); Nelfinavir; Nevirapine; Rifampicin; §Rifabutin and
Saquinavir.