What role for hydroxyurea?
Much interest has developed around hydroxyurea, and further studies will continue to evaluate its potential role as an adjunct to antiretroviral therapy. Hydroxyurea has been used as a component of several HAART regimens, especially those containing didanosine (ddI), with which it has synergistic anti-HIV effects.45,46 This novel approach to antiretroviral therapy exploits hydroxyurea’s selective inhibition of cellular ribonucleotide reductase. Inhibition of ribonucleotide reductase dramatically decreases intracellular deoxyribonucleoside triphosphate (dNTP) pools. As such, although hydroxyurea is not a primary antiretroviral agent, it inhibits HIV replication by indirectly blocking reverse transcriptase, which depends on intracellular dNTPs as substrates.47-49 Several clinical studies have demonstrated the in vitro and in vivo efficacy of hydroxyurea in inhibiting HIV replication when combined with ddI and other nucleoside reverse transcriptase inhibitors. Research also suggests that
