Efavirenz (Sustiva) Drug for AIDS/HIV: Use, Side Effects, Interactions

Efavirenz
(Sustiva, United States)

Use:

Efavirenz or Sustiva is an anti retroviral drug used in conditions such as HIV infections and AIDS.

How It Works:

Efavirenz or Sustiva is a non-nucleoside reverse transcriptase inhibitor. It inhibits the same viral enzyme that AZT does, and can be used in combination with AZT.
It is used as second line therapy after initial therapy with AZT. An increased survival rate is seen because with prolonged use of AZT, resistance develops.
Examples of other drugs for HIV infections: nucleoside analogs - didanosine, lamivudine, stavudine, zalcitabine, zidovudine (AZT); protease inhibitors - indinavir, ritonavir, saquinavir.

Side Effects:

The most common side effects of Efavirenz or Sustiva have been dizziness, headache, insomnia, inability to concentrate, and rash. Vivid dreams, nightmares, and hallucinations can occur. With time these side effects diminish.

Cautions for People:

Efavirenz or Sustiva has been associated with birth defects, thus should not be used by pregnant individuals.

Drug Interactions:

Efavirenz or Sustiva is often used in combination regimes for the treatment of HIV infections. However, because it can increase the metabolism of some drugs, the dose of protease inhibitor indinavir needs to be increased. Efavirenz or Sustiva also decreases the concentrations of clarithromycin, but not azithromycin.

Further Reading:

Medical Letter 1998;40(1041):114

Added to Virtual Drugstore May 1999.

The relevant product monographs must be regarded as the appropriate sources of prescribing information.