General Information

Sustiva was approved in 1998 in capsule formulation, for the treatment of human immunodeficiency virus (HIV) infection, in combination with other anti-retroviral agents.

Mechanism of Action

Sustiva (efavirenz) is a non-nucleoside reverse transcriptase (RT) inhibitor of HIV type 1. It acts predominantly through the non-competitive inhibition of HIV-1 RT. The drug does not inhibit HIV-2 RT or human cellular DNA polymerases alpha, beta, gamma and delta.

Side Effects

Adverse events associated with the use of Sustiva may include (but are not limited to) the following:

• skin rash (more common in children)
• dizziness
• depression
• anxiety
• nausea
• fatigue
• impaired concentration
• abnormal dreaming

Dosing/Administration

In February 2002, the tablet formulation of the drug was approved. It is now possible, instead of taking three 200 mg capsules once-daily, to take a single 600 mg tablet once-daily. Sustiva is listed by United States Department of Health and Human Services as the only non-nucleoside reverse transcriptase inhibitor "strongly recommended" for use in combination with nucleoside reverse transciptase inhibitors for HIV treatment.

Close to 1 million Americans are now infected with HIV, the virus that causes acquired immunodeficiency syndrome (AIDS). Each year only a little over one third of those infected receive anti-HIV treatments regimens. Most of those that do get treatment are forced to take numerous pills, often throughout the day. Innovations in drug formulations, such as single once-daily doses of Sustiva, can help simplify daily dosing regimens.

Clinical Trial Results

The approval of Sustiva 600 mg tablets is supported by two studies conducted in 1,462 HIV infected subjects. Both compared Sustiva, in combination with other anti-retroviral agents, to other anti-retroviral drug combinations. The regimens that included Sustiva 600 mg tablets elicited comparable and superior increases in CD4 cell counts from baseline to post-treatment.