Open study of 2-amino-9-(hydroxyethoxymethyl)-9H-purine (desciclovir) in the treatment of herpes zoster.

An oral pro-drug of acyclovir, 2-amino-9-(2-hydroxyethoxymethyl)-9H-purine (desciclovir) was evaluated in an open study comprising of 20 patients with herpes zoster. The clinical effects were comparable to those obtained with oral and intravenous acyclovir, even with a dosage of only 125 mg thrice daily. There was adequate absorption though considerable individual variation occurred. No effects of concomitant food intake were demonstrated. The finding of possible impaired conversion of desciclovir to acyclovir in one patient was unexplained and deserves attention in future studies. Likewise, more studies are needed to understand the occurrence of transient high peak plasma concentrations of acyclovir. Side-effects other than those already known with the use of acyclovir, namely reversible tubular damage, were not observed.