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Valacyclovir Disease Interactions

There are 3 disease interactions with valacyclovir:

Major

Valacyclovir (Includes valacyclovir) ↔ renal impairment

Major Potential Hazard, High plausibility. Applies to: Renal Dysfunction

Valacyclovir is almost completely converted in vivo to acyclovir, which is primarily eliminated by the kidney. Patients with renal impairment may be at greater risk for neuro- and nephrotoxicity (including further deterioration in renal function, tubular damage and acute renal failure) from acyclovir due to decreased drug clearance. Therapy with valacyclovir should be administered cautiously in patients with renal impairment. Dosage adjustments are recommended in patients with moderate to severe renal dysfunction.

References

  1. "Product Information. Valtrex (valacyclovir)." Glaxo Wellcome, Research Triangle Park, NC.
  2. Laskin OL, Longstreth JA, Whelton A, et al "Acyclovir kinetics in end-stage renal disease." Clin Pharmacol Ther 31 (1982): 594-600
  3. Laskin OL, Longstreth JA, Whelton A, et al "Effect of renal failure on the pharmacokinetics of acyclovir." Am J Med 73 (1982): 197-201
Major

Valacyclovir (Includes valacyclovir) ↔ TTP/HUS

Major Potential Hazard, Low plausibility. Applies to: Organ Transplant, Immunodeficiency, Bone Marrow Transplantation, Neutropenia

Cases of thrombotic thrombocytopenic purpura/hemolytic uremia have been reported in patients with advanced HIV disease and in allogeneic bone marrow transplant and renal transplant recipients given valacyclovir 8 g/day during clinical trials. Although a causal relationship has not been established, therapy with valacyclovir should be administered cautiously in immunocompromised patients.

References

  1. "Product Information. Valtrex (valacyclovir)." Glaxo Wellcome, Research Triangle Park, NC.
Moderate

Valacyclovir (Includes valacyclovir) ↔ hemodialysis

Moderate Potential Hazard, High plausibility. Applies to: hemodialysis

Valacyclovir is almost completely converted in vivo to acyclovir, which is substantially removed by hemodialysis. Plasma levels of acyclovir have been shown to reduce by 60% following 6 hours of dialysis. Valacyclovir should be administered after hemodialysis. Otherwise, an additional dose may be given after each hemodialysis session.

References

  1. Krasny HC, Liao SH, de Miranda P, Laskin OL, Whelton A, Lietman PS "Influence of hemodialysis on acyclovir pharmacokinetics in patients with chronic renal failure." Am J Med 73 (1982): 202-4
  2. Laskin OL, Longstreth JA, Whelton A, et al "Acyclovir kinetics in end-stage renal disease." Clin Pharmacol Ther 31 (1982): 594-600
  3. "Product Information. Valtrex (valacyclovir)." Glaxo Wellcome, Research Triangle Park, NC.

Valacyclovir drug interactions

There are 58 drug interactions with valacyclovir

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.