Coming therapies: abacavir.

Abacavir is a nucleoside analogue reverse transcriptase inhibitor (NRTI). It has a good oral availability and penetrates the CNS. The metabolism of abacavir is not dependent on cytochrome P450 thus avoiding significant drug-drug interactions. It has an antiviral potency comparable to that of protease inhibitors (PIs) or to dual nucleoside combinations. In addition, evidence has shown that it is effective in decreasing viral load and increasing CD4 count in HIV-infected patients, especially NRTI-naïve patients. Abacavir has an acceptable tolerability profile, although hypersensitivity reactions lead to discontinuation of therapy in approximately 3% of patients. Abacavir has a potential role in first- and second-line combination regimens and as part of a PI-sparing regimen.