Abstract
Acyclovir is highly useful for treatment of herpes virus infection. It is excreted primarily by kidneys. Therefore it gets accumulated in patients with renal dysfunction. There are reports to suggest that acyclovir usage could lead to neurotoxicity characterized by disorientation, decreased level of consciousness, dysarthria, tremors, seizures, hallucinations and coma. Acyclovir induced neurotoxicity has been found with patients on dialysis or not on dialysis. We present here five cases of CKD who developed neurotoxicity after use of acyclovir for herpes zoster. They had disorientation, decreased level of consciousness, dysarthria, tremors, seizures and hallucinations 2-4 days after administration of acyclovir. Acyclovir induced neurotoxicity was suspected because we could not find any other cause for neurological symptoms in these patients. Acyclovir was discontinued in all cases and haemodialysis sessions were given. One patient was managed by increasing number of exchanges of peritoneal dialysis. All patients recovered in 3-5 days after discontinuation of drug. Main factors for acyclovir induced neurotoxicity are advance age , renal failure, inappropriate dose of acyclovir in relation to creatinine clearance. Acyclovir induced neurotoxicity should be suspected in patients with renal dysfunction those present with neurological symptoms 2=4 days after taking of drug. These patients should be treated with discontinuation of acyclovir and judicious use of haemodialysis. Physicians should adjust the dose of acyclovir according to creatinine clearance to minimize toxicity.

Key words: Dialysis, herpes zoster, dose adjustment, decreased consciousness