Maraviroc is the first co-receptor antagonist to be approved for use in HIV infected patient. In a phase II trial, in which the drug was administered as a single therapy, the most suitable maintenance dose was 300 mg, once or twice per day. The MOTIVATE double blind, placebo-compared studies, were carried out on patients infected by HIV-1 with R5 tropism and resistant to drugs from three families of retrovirals. Maraviroc two times per day achieved < 50 copies/mL in 45.5% of the patients compared to 16.7% in the placebo group (p < 0.001). The CD4+ lymphocyte count had a mean of 63 cells/mm(3) higher with Maraviroc. The drug was shown to be superior in all patient groups regardless of the baseline viral load, the baseline CD4+ lymphocyte count or the number of accompanying active drugs. In the study on patients infected by HIV with X4/dual/mixed tropism, Maraviroc, was not virologically effective, but did produce a CD4 increase higher than the placebo. Maraviroc was compared with Efavirenz in the study on patients with no previous treatment and with R5-tropic virus. At 48 weeks, the percentage of patients with a viral load of <50 copies/mL was 69.3% in the group that received Efavirenz and 65.3% in the Maraviroc group. In conclusion, Maraviroc has demonstrated its increased efficacy in patients with CCR5-tropic virus and a long history of antiretroviral use and failure, and in patients with no previous treatment.