Infusion: In patients receiving Zovirax IV for infusion at higher doses (eg, for herpes encephalitis), specific care regarding renal function should be taken, particularly when patients are dehydrated or have any renal impairment. Reconstituted Acyclovir Zovirax IV for infusion has a pH of approximately 11 and should not be administered by mouth.
Hydration Status: Tablet: Care should be taken to maintain adequate hydration in patients receiving high oral doses of acyclovir.
Renal Impairment: Tablet: Acyclovir is eliminated by renal clearance; therefore the dose must be reduced in patients with renal impairment (see Dosage & Administration).
Effects on the Ability to Drive or Operate Machinery: Tablet: The clinical status of the patient and the adverse event profile of Zovirax should be borne in mind when considering the patient's ability to drive or operate machinery. There have been no studies to investigate the effect of acyclovir on driving performance or the ability to operate machinery. Further, a detrimental effect on such activities cannot be predicted from the pharmacology of the active substance.
Infusion: Zovirax IV for infusion is generally used in an in-patient hospital population and information on ability to drive and operate machinery is not usually relevant. There have been no studies to investigate the effect of acyclovir on driving performance or the ability to operate machinery.
Use in Elderly: Elderly patients are likely to have reduced renal function and therefore, the need for dose reduction must be considered in this group of patients. Both elderly patients and patients with renal impairment are at increased risk of developing neurological side effects and should be closely monitored for evidence of these effects. In the reported cases, these reactions were generally reversible on discontinuation of treatment (see Adverse Reactions).