Symptoms & Signs: Overdosage of IV acyclovir has resulted in elevations of serum creatinine, blood urea nitrogen and subsequent renal failure. Neurological effects including confusion, hallucinations, agitation, seizures and coma have been described in association with IV overdosage.
Tablet: Acyclovir is only partly absorbed in the gastrointestinal tract. Patients have ingested overdoses of up to acyclovir 20 g on a single occasion, usually without toxic effects. Accidental repeated overdoses of oral acyclovir over several days have been associated with GI effects (eg, nausea and vomiting) and neurological effects (headache and confusion).
Treatment: Patients should be observed closely for signs of toxicity. Hemodialysis significantly enhances the removal of acyclovir from the blood and may therefore, be considered a management option in the event of symptomatic overdose.