Drug interactions of HIV protease inhibitors.

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Malaty LI, Kuper JJ

Drug interactions of HIV protease inhibitors.

Drug Saf. 1999 Feb;20(2):147-69. doi: 10.2165/00002018-199920020-00005.

PubMed ID

10082072 [ View in PubMed

]

Abstract

All the currently available protease inhibitors are metabolised by the cytochrome P450 (CYP) enzyme system. All are inhibitors of CYP3A4, ranging from weak inhibition for saquinavir to very potent inhibition for ritonavir. Thus, they are predicted to have numerous drug interactions, although few such interactions have actually been documented either in pharmacokinetic studies or in clinical reports. This article reviews the published literature with an emphasis on the magnitude of interactions and on practical recommendations for management. Many of the drugs commonly taken by patients with HIV have a strong potential to interact with the protease inhibitors. In particular, the non-nucleoside reverse transcriptase inhibitors are also metabolised by CYPand have been shown to interact with protease inhibitors. Delaviridine is an inhibitor of CYP3A4, but nevirapine and efavirenz are inducers of CYP3A4. The protease inhibitors also interact with each other, and these interactions are being explored for their potential therapeutic benefits. Other commonly used drugs are also known to affect protease inhibitor metabolism, including inhibitors such as clarithromycin and the azole antifungals and inducers such as the rifamycins. Drugs that are known to be significantly affected by the protease inhibitors include ethinylestradiol and terfenadine; many other drugs have lesser or potential interactions. Although little specific data is available on the drug interactions of protease inhibitors, this lack of data should not be interpreted as a lack of interaction. Retrospective chart reviews have demonstrated that potentially severe drug interactions are frequently overlooked. Much more clinical data is needed, but pharmacists and physicians must always be vigilant for drug interactions, both those that are already documented and those that are predictable from pharmacokinetic profiles, in patients receiving protease inhibitors.

DrugBank Data that Cites this Article

Drug Enzymes

Drug	Enzyme	Kind	Organism	Pharmacological Action	Actions
Efavirenz	Cytochrome P450 3A4	Protein	Humans	Unknown	Substrate Inhibitor Inducer	Details

Drug Interactions

• Approved
• Vet approved
• Nutraceutical
• Illicit
• Withdrawn
• Investigational
• Experimental
• All Drugs

Drugs	Interaction
Integrate drug-drug interactions in your software
Ketoconazole Saquinavir	The serum concentration of Ketoconazole can be increased when it is combined with Saquinavir.
Voriconazole Amprenavir	The serum concentration of Voriconazole can be increased when it is combined with Amprenavir.
Voriconazole Fosamprenavir	The serum concentration of Voriconazole can be increased when it is combined with Fosamprenavir.
Voriconazole Tipranavir	The serum concentration of Voriconazole can be increased when it is combined with Tipranavir.
Voriconazole Asunaprevir	The serum concentration of Voriconazole can be increased when it is combined with Asunaprevir.