Acyclovir tolerance in humans.

Acyclovir tolerance has been explored in a broad range of human populations and dosage regimens with intravenous, topical, and oral formulations. Phase I pharmacokinetic/tolerance studies assured safety in special populations at unique risk of complicated herpes infections who were simultaneously at increased risk of toxicity to anti-DNA chemotherapeutic agents. Further safety evaluations accompanied placebo-controlled Phase II studies in infected patients who represent future users of acyclovir. These studies confirm acyclovir as the safest antiherpes agent to be explored in clinical studies to date.