Australia - Valaciclovir is an antiviral prodrug of aciclovir used in the treatment of herpes infections.

The Adverse Drug Reactions Advisory Committee has received 69 reports of minor reactions including headache, nausea, rash, dizziness. However, 13 more severe neuropsychiatric reactions have been reported and include hallucination, confusion, delirium, ataxia, dysarthria, convulsions, psychosis and stupor. Of these, all but one occurred in patients with chronic renal failure or age-related renal impairment. Although this is consistent with the product information physicians should be made aware of the possibility of these risks.

Reference: Australian Adverse Drug Reactions Bulletin, 19: 2 (2000).