Delavirdine is an anti-AIDS drug approved for use in the United States in 1997. It is produced by Pharmacia and Upjohn under the brand name of Rescriptor®. Delavirdine is taken orally and is meant to be used in conjunction with other anti-AIDS therapies to improve their effectiveness.

Delavirdine is a non-nucleoside reverse transcriptase inhibitor that works to prevent reverse transcriptase from replicating the HIV genome. This drug acts early in the infection of a cell to prevent the viral genome from being turned into DNA. Without this vital step, HIV cannot carry out its replication cycle.

Delavirdine binds to a cleft in the p66 subunit of the polymerase to inhibit polymerization at this site. The RNA-dependent DNA polymerase of HIV has been described as a right handed fist, and the binding site of this drug can be thought of as in the ?palm? of this fist. Once binding of the drug has occurred, the polymerase can no longer bind to the viral RNA.

Delavirdine is a pill taken three times daily. It must be used in conjunction with other anti-HIV drugs (such as zidovudine, didanosine, lamivudine, protease inhibitors or interferon-a) or resistant viruses will develop quite quickly.

FDA clearance of this drug was given under the provisions of accelerated approval regulations for anti-AIDS drugs as clinical trials have not shown an large increase in lifespan or reduced incidence of the virus when this drug is used.

In studies done where this drug was part of a three-drug therapy (the other two drugs were zidovudine and didanosine), there was not shown to be a statistically significant difference in the levels of plasma HIV RNA or in CD4 counts. However, when delavirdine was used in a two-drug therapy with a protease inhibitor, subjects were found to have a decreased viral load even if they had previously failed Indinavir combination therapy.

Rescriptor® is taken in a 400mg dose three times daily. It may be dissolved in liquid or taken as a solid pill. It must be used in a multi-drug therapy. Absorbency is fairly rapid and peak levels occur in the blood approximately an hour after the drug is taken. Amount of food in stomach makes no difference to absorption of the drug.

The most common side effect is a diffuse maculopapular rash that concentrates on the upper body (observed in 18% of subjects in clinical trials). The rash typically occurs within 1-3 weeks of beginning the therapy and will last for about 2 weeks.

Pharmacia and Upjohn Website
http://www.pnuaids.com/

ACTG Study Presented at Second International Workshop on Salvage Therapy for HIV Infection. "Study Finds Twice Daily RESCRIPTOR® Enhances PI Effect, Decreases Viral Load Among HIV Patients Who Fail Indinavir Combination Therapy." May 20, 1999.

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Created: March 1st, 2000
Updated: March 5th, 2000