Synthetic nucleoside. Two references consider it safe.

Antiviral (herpes) nucleoside with aliphatic side chain. Eliminated in urine as penciclovir and its 6-deoxy precursor. South African list: use. French list: use. Thunell: Given to one female AIP patient, 52 years, without ill effects.

Uneventful use reported in 1 patient with acute porphyria.