Valtrex Special Precautions

Hydration status: Care should be taken to ensure adequate fluid intake in patients who are at risk of dehydration, particularly the elderly.
Use of higher doses of Valaciclovir (Valtrex) in hepatic impairment and liver transplantation: There are no data available on the use of higher doses of Valaciclovir (Valtrex) (4 g or more/day) in patients with liver disease. Caution should therefore be exercised when administering higher doses of Valaciclovir (Valtrex) to these patients. Specific studies of Valaciclovir (Valtrex) have not been conducted in liver transplantation; however high dose aciclovir prophylaxis has been shown to reduce CMV infection and disease.
Use in genital herpes: Suppressive therapy with Valaciclovir (Valtrex) reduces the risk of transmitting genital herpes. It does not cure genital herpes or completely eliminate the risk of transmission. In addition to therapy with Valaciclovir (Valtrex), it is recommended that patients use safer sex practices.
Effects on Ability to Drive and Use Machines: The clinical status of the patient and the adverse event profile of Valaciclovir (Valtrex) 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 valaciclovir 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.
Use in patients with renal impairment and in elderly patients: Aciclovir is eliminated by renal clearance, therefore the dose of valaciclovir must be reduced in patients with renal impairment (see Dosage & Administration). 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).