Maravirok

Maravirok is an antiretroviral medication that acts as a selective antagonist of the CCR5 receptor. It is used to treat HIV-1 infection in adults and in certain pediatric patients who have CCR5-tropic virus, as part of combination antiretroviral therapy. By binding to CCR5 on the surface of CD4+ T cells and macrophages, maravirok blocks the interaction between gp120 and CCR5, thereby preventing viral entry into the cell.

Maravirok’s activity is restricted to CCR5-tropic (R5) HIV-1. It is not effective against CXCR4-tropic (X4) or dual/mixed-tropic viruses. Before starting maravirok, and whenever virologic failure is suspected, tropism testing is required to confirm that the patient’s virus uses CCR5.

The drug is taken orally twice daily, with or without food. The standard adult dose is 300 mg twice daily, but dosing adjustments are required based on drug interactions that affect CYP3A4 metabolism: potent CYP3A4 inhibitors may necessitate a dose reduction (for example to 150 mg twice daily), while potent CYP3A4 inducers may require a higher dose (for example up to 600 mg twice daily). Pediatric dosing exists for children aged 2 years and older and depends on weight and co-medications.

Common adverse effects include fever, upper respiratory tract infections, rash, and abdominal pain. Hepatotoxicity has been reported, so liver function monitoring is advised. Maravirok is marketed under the brand name Selzentry in many markets.