Products
Efavirenz is commercially available as film-coated tablets and as an oral solution (Stocrin, combination products, generics). It has been approved in many countries since 2001.
Structure and properties
Efavirenz (C14H9ClF3NO2, Mr = 315.7 g/mol) exists as a white to light pink crystalline powder that is practically insoluble in water. It has a non-nucleoside structure (NNRTI).
Effects
Efavirenz (ATC J05AG03) is antiviral against HIV-1, with effects based on inhibition of viral reverse transcriptase and thus inhibition of viral replication.
Indications
For the treatment of infections with HIV (combination antiretroviral therapy).
Dosage
According to the SmPC. The drug should be taken in the evening, fasting, before sleeping. It has a long half-life and therefore can be administered once daily.
Contraindications
Efavirenz is contraindicated in hypersensitivity and severe liver disease. It must not be combined with CYP3A4 substrates with a narrow therapeutic range, voriconazole, and St. John’s wort. For complete precautions and interactions information, see the Drug Information Leaflet.
Interactions
Efavirenz is metabolized by CYP3A4 and CYP2B6, inhibits CYP3A4, CYP2C9, and CYP2C19, and induces CYP3A4. Accordingly, there is a high potential for drug-drug interactions.
Adverse effects
The most common potential adverse effects include rash, dizziness, nausea, headache, and fatigue.
