Acyclovir. Pharmacology and clinical experience.

Acyclovir is a selective antiherpes agent. Its selective activity is by exploitation of differences between the herpes-specific and host cell enzymes. The major route of elimination of acyclovir is via the kidney by glomerular filtration and renal tubular secretion. In immunocompromised patients, acyclovir is effective for the prophylaxis and therapy of herpes simplex virus infections and for the treatment of herpes zoster and varicella. In nonimmunocompromised patients, acyclovir is beneficial in the therapy of herpes keratoconjunctivitis and in the therapy of genital herpes, with maximal benefit seen in those patients who have primary genital herpes. There is some benefit from acyclovir administration in patients with herpes zoster who are otherwise normal. The toxic reactions to acyclovir consist of phlebitis, local irritation, and occasionally, reversible renal dysfunction. Dose reduction is recommended in patients with impaired renal function.