Hydroxyurea in the treatment of HIV-1 infection: toxicity and side effects

Hydroxyurea has been used in numerous clinical trials for the treatment of HIV-1 infection, almost always in combination with didanosine with or without other antiretrovirals. Due to its inhibition of DNA synthesis, the main side effect of hydroxyurea is myelosuppression. When administered at the dosage of 1000 mg/day in asymptomatic, moderately-immunosuppressed HIV-1 infected patients, its tolerability profile appears to be quite favourable, with rare, reversible episodes of peripheral blood cytopenia that seldom require therapy discontinuation. Higher dosages of hydroxyurea and its use in advanced, heavily-pretreated patients may increase the likelihood of more severe side effects or newer toxicities developing. So far hydroxyurea-containing long therapy courses, up to 3 years, have not elicited any significant toxicity and appear to be safe as in onco-hematologic patients.