Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) for the treatment of HIV infection in adults. It was developed and is marketed by Gilead Sciences with the brand name Emtriva.

Mode of action

The drug works by inhibiting reverse transcriptase, the enzyme that copies HIV RNA into new viral DNA. By interfering with this process, which is central to the replication of HIV, emtricitabine can help to lower the amount of HIV, or "viral load", in a patient's body and can indirectly increase the number of immune system cells (called T cells or CD4+ T-cells). Both of these changes are associated with healthier immune systems and decreased likelihood of serious illness.

Indications

Emtricitabine is indicated in combination with other antiretroviral agents for the treatment of HIV infection in adults. This indication is based on the analyses of plasma HIV RNA levels and CD4 cell counts in two Phase III clinical trials of Emtriva of 48 weeks duration.

It is not indicated for the treatment of chronic hepatitis B virus infection and the safety and efficacy of emtricitabine have not been established in patients co-infected with HBV and HIV. Severe acute exacerbations of hepatitis B have been reported in patients after the discontinuation of emtricitabine. The drug is however being evaluated as a potential treatment for chronic hepatitis B. These studies are ongoing.

Side-effects

In clinical practise, toxicity with emtricitabine is unusual. The most common treatment-related adverse events are diarrhoea, headache, nausea, and rash. These symptoms are generally mild to moderate severity, but they caused 1% of clinical trial patients to give up treatment. Skin discolouration, which is typically reported as hyperpigentation and usually affecting either the palms of the hands or the soles of the feet, is reported in under 2% of individuals and is almost exclusive to patients of African origin.

External links

• Emtriva web site