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Zovirax (acyclovir) Disease Interactions

There are 4 disease interactions with Zovirax (acyclovir):


Acyclovir (Includes Zovirax) ↔ Renal Dysfunction

Severe Potential Hazard, High plausibility

Applies to: Renal Dysfunction

Acyclovir 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 acyclovir should be administered cautiously in patients with renal impairment. Dosage adjustments are recommended in patients with moderate to severe renal dysfunction.


  1. Laskin OL, Longstreth JA, Whelton A, et al "Effect of renal failure on the pharmacokinetics of acyclovir." Am J Med 73 (1982): 197-201
  2. Johnson GL, Limon L, Trikha G, Wall H "Acute renal failure and neurotoxicity following oral acyclovir." Ann Pharmacother 28 (1994): 460-3
  3. Laskin OL, Longstreth JA, Whelton A, et al "Acyclovir kinetics in end-stage renal disease." Clin Pharmacol Ther 31 (1982): 594-600
View all 13 references

Acyclovir (Includes Zovirax) ↔ Dehydration

Moderate Potential Hazard, High plausibility

Applies to: Dehydration

Acyclovir crystals may precipitate in the renal tubules, particularly when the drug is injected intravenously as a bolus. Abnormal renal function may occur, which is usually reversible but may infrequently progress to tubular damage and acute renal failure. Patients who are dehydrated may be at increased risk for nephrotoxicity from acyclovir administration. Intravenous acyclovir should be administered over a one-hour period accompanied by adequate hydration. The urine flow should be monitored, especially within the first two hours following infusion when maximum urine concentration occurs. The recommended urine output is a minimum of 500 mL per gram of drug infused.


  1. "Product Information. Zovirax (acyclovir)." Mylan Pharmaceuticals Inc, Morgantown, WV.

Acyclovir (Includes Zovirax) ↔ Hemodialysis

Moderate Potential Hazard, High plausibility

Applies to: hemodialysis

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


  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. "Product Information. Zovirax (acyclovir)." Mylan Pharmaceuticals Inc, Morgantown, WV.

Acyclovir (Includes Zovirax) ↔ Neurotoxicity

Moderate Potential Hazard, Low plausibility

Applies to: Liver Disease, Electrolyte Abnormalities, Hypernatremia, Phosphate Imbalance, Magnesium Imbalance, Asphyxia, CNS Disorder, Hyponatremia, Dehydration, Hypocalcemia, Hypercalcemia, Acidosis, Alkalosis

Acyclovir, particularly when administered intravenously in higher dosages, may occasionally produce neurotoxicity characterized by lethargy, obtundation, tremors, confusion, hallucinations, agitation, seizures, or coma. Therapy with acyclovir should be administered cautiously in the elderly and in patients with underlying neurologic abnormalities, severe renal or liver disease, or significant electrolyte abnormalities or hypoxia.


  1. Feldman S, Rodman J, Gregory B "Excessive serum concentrations of acyclovir and neurotoxicity." J Infect Dis 157 (1988): 385-8
  2. Jones PG, Beier-Hanratty SA "Acyclovir: neurologic and renal toxicity." Ann Intern Med 104 (1986): 892
  3. Rashiq S, Briewa L, Mooney M, Giancarlo T, Khatib R, Wilson FM "Distinguishing acyclovir neurotoxicity from encephalomyelitis." J Intern Med 234 (1993): 507-11
View all 12 references

Zovirax (acyclovir) drug Interactions

There are 76 drug interactions with Zovirax (acyclovir)

Drug Interaction Classification

The classifications below are a general guideline only. It is difficult to determine the relevance of a particular drug interaction to any individual given the large number of variables.
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 information available.

Do not stop taking any medications without consulting your healthcare provider.

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