Optimal use of maraviroc in clinical practice

Maraviroc belongs to a new class of anti-HIV drugs named CCR5 antagonists, which block HIV entry into cells. It has proven potent efficacy in treatment-experienced patients with multiple drug failure. Its favourable toxicity profile makes the drug attractive for consideration in other clinical scenarios, including patients with earlier stages of disease, cardiovascular risk and viral hepatitis coinfection. Because of its unique mechanism of action-blocking viral entry, studies in patients with primary HIV infection and in the context of preexposure and postexposure prophylaxis are particularly warranted. However, given its exclusive activity against CCR5 tropic strains, viral tropism testing is mandatory before using CCR5 antagonists in the clinic. Efforts to improve the reliability of viral tropism assessment using genotypic tests are underway, and it is likely that these tools will soon replace phenotypic assays, which are more expensive, difficult to perform and take a long time. © 2008 Wolters Kluwer Health Lippincott Williams & Wilkins.