Adults and Children: Zovirax Cream should be applied five times daily at approximately four hourly intervals, omitting the night time application. Treatment should be continued for 5 days. If, after 5 days, healing is not complete then treatment may be continued for up to an additional 5 days. Zovirax Cream should be applied to the lesion or impending lesion as early as possible after the start of an infection. It is particularly important to start treatment of recurrent episodes during the prodromal period or when lesions first appear.

Zovirax Cream is not recommended for application to mucous membranes such as in the mouth, eye or vagina, as it may be irritant.

Particular care should be taken to avoid accidental introduction into the eye.

In severely immunocompromised patients (eg AIDS patients or bone marrow transplant recipients) oral Zovirax dosing should be considered. Such patients should be encouraged to consult a physician concerning the treatment of any infection.

Largely reversible adverse effects on spermatogenesis in association with overall toxicity in rats and dogs have been reported only at doses of aciclovir greatly in excess of those employed therapeutically. There has been no experience of the effect of Zovirax cream on human fertility. Two generation studies in mice did not reveal any effect of (orally administered) aciclovir on fertility. Zovirax Tablets have been shown to have no definite effect upon sperm count, morphology or motility in man.

The results of a wide range of mutagenicity tests in vitro and in vivo indicate that aciclovir does not pose a genetic risk to man.

Aciclovir was not found to be carcinogenic in long term studies in the rat and the mouse.

Zovirax Cream contains a specially formulated base and should not be diluted or used as a base for the incorporation of other medicaments.