Valacyclovir warnings and precautions

Valacyclovir
VALTREX® FDA Package Insert
Description
Clinical Pharmacology
Microbiology
Indications and Usage
Contraindications
Warnings and Precautions
Adverse Reactions
Overdosage
Clinical Studies
Dosage and Administration
How Supplied
Labels and Packages

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sheng Shi, M.D. [2]

Warnings And Precautions

Thrombotic Thrombocytopenic Purpura/Hemolytic Uremic Syndrome (TTP/HUS)

TTP/HUS, in some cases resulting in death, has occurred in patients with advanced HIV─1 disease and also in allogeneic bone marrow transplant and renal transplant recipients participating in clinical trials of VALTREX at doses of 8 grams per day. Treatment with VALTREX should be stopped immediately if clinical signs, symptoms, and laboratory abnormalities consistent with TTP/HUS occur.

Acute Renal Failure

Cases of acute renal failure have been reported in:

• Elderly patients with or without reduced renal function. Caution should be exercised when administering VALTREX to geriatric patients, and dosage reduction is recommended for those with impaired renal function [see Dosage and Administration (2.4), Use in Specific Populations (8.5)].
• Patients with underlying renal disease who received higher-than-recommended doses of VALTREX for their level of renal function. Dosage reduction is recommended when administering VALTREX to patients with renal impairment [see Dosage and Administration (2.4), Use in Specific Populations (8.6)].
• Patients receiving other nephrotoxic drugs. Caution should be exercised when administering VALTREX to patients receiving potentially nephrotoxic drugs.
• Patients without adequate hydration. Precipitation of acyclovir in renal tubules may occur when the solubility (2.5 mg/mL) is exceeded in the intratubular fluid. Adequate hydration should be maintained for all patients.

In the event of acute renal failure and anuria, the patient may benefit from hemodialysis until renal function is restored [see Dosage and Administration (2.4), Adverse Reactions (6.3)].

Central Nervous System Effects

Central nervous system adverse reactions, including agitation, hallucinations, confusion, delirium, seizures, and encephalopathy, have been reported in both adult and pediatric patients with or without reduced renal function and in patients with underlying renal disease who received higher-than-recommended doses of VALTREX for their level of renal function. Elderly patients are more likely to have central nervous system adverse reactions. VALTREX should be discontinued if central nervous system adverse reactions occur [see Adverse Reactions (6.3), Use in Specific Populations (8.5, 8.6)].

References

Adapted from the FDA Package Insert.