Acyclovir Adverse Reactions
- abdominal pain
- agitation
- alopecia
- anaphylactoid reactions
- anemia
- angioedema
- anorexia
- ataxia
- azotemia
- coma
- confusion
- crystalluria
- delirium
- diarrhea
- dizziness
- dysarthria
- elevated hepatic enzymes
- encephalopathy
- erythema multiforme
- fever
- hallucinations
- headache
- hematuria
- hemolytic-uremic syndrome
- hepatitis
- hyperbilirubinemia
- injection site reaction
- jaundice
- leukopenia
- lymphadenopathy
- myalgia
- nausea/vomiting
- paresthesias
- peripheral edema
- phlebitis
- photosensitivity
- pruritus
- psychosis
- rash (unspecified)
- renal failure (unspecified)
- renal tubular obstruction
- seizures
- skin irritation
- skin ulcer
- Stevens-Johnson syndrome
- thrombocytopenia
- thrombotic thrombocytopenic purpura (TTP)
- tissue necrosis
- toxic epidermal necrolysis
- tremor
- urticaria
Acyclovir Adverse Reactions
Systemic acyclovir is associated with nephrotoxicity, which occurs as a result of crystallization of the drug within the nephron. Acyclovir has low solubility in urine. Low urine volume associated with volume contraction may contribute to crystalluria. Crystalluria can lead to azotemia, renal tubular obstruction, and renal failure leading to death. Crystalluria is more likely to occur during administration of large, parenteral doses or in patients who are dehydrated. Rapid or bolus infusions of acyclovir have been associated with renal toxicity. Acyclovir serum concentrations > 20 mcg/ml seen following intravenous doses of acyclovir 500 mg/m2 have also been correlated with renal toxicity. Maintaining adequate hydration and a high urine flow should minimize the occurrence of crystalluria. In the event of renal failure and anuria, the patient may benefit from hemodialysis until renal function is restored. It is recommended that renal and fluid status be monitored during acyclovir therapy.
Neurotoxicity has been reported during systemic acyclovir administration, especially when administered in high doses and/or in patients with renal impairment. Neurotoxicity can include coma, confusion, delirium, encephalopathy, hallucinations, paresthesias, psychosis, seizures, or tremor. Neurologic adverse reactions usually occur within 1-2 days of achieving the maximum acyclovir concentration and may not be directly correlated with the present acyclovir serum concentrations. Seizures and lethargy have been reported in association with acyclovir overdose. Other neurologic effects reported with acyclovir therapy include headache and lightheadedness.
Injection site reactions can be severe with parenteral acyclovir; phlebitis or vesicular eruptions (skin ulceration) can occur. Avoid using the same IV site if a reaction develops. More concentrated acyclovir solutions (i.e., > 7 mg/ml) are associated with an increased risk of infusion-related reactions; final acyclovir infusion concentrations > 10 mg/ml are not recommended. Severe local inflammatory reactions, including tissue necrosis, have occurred following infusion of acyclovir into extravascular tissues.
Abdominal pain, anorexia, diarrhea, elevated hepatic enzymes, hepatitis, hyperbilirubinemia, jaundice, and nausea/vomiting are reported GI adverse effects of systemic acyclovir therapy. Rarely hematologic reactions including leukopenia, lymphadenopathy, and thrombocytopenia have been reported during acyclovir therapy. Other adverse reactions to acyclovir include anaphylactoid reactions and myalgia.
Dermatologic reactions to acyclovir include alopecia, erythema multiforme, photosensitivity rash, pruritus, rash (unspecified), Stevens-Johnson syndrome, toxic epidermal necrolysis, and urticaria. Skin irritation (e.g., mild pain, stinging, burning) was reported in 30% of patients receiving acyclovir ointment or placebo; localized pruritus was reported in 4% of patients.
Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) have occurred in immunocompromised patients receiving acyclovir therapy; some of these events have resulted in patient death.
Post-marketing adverse events associated with acyclovir have been reported, although estimates of frequency cannot be determined as the reports are from a population of unknown size. Most post-marketing reported adverse events are similar to adverse events reported in clinical trials, except for the following: aggressive behavior, agitation, anemia, angioedema, ataxia, decreased consciousness, dizziness, dysarthria, gastrointestinal distress, fever, hematuria, elevated blood urea nitrogen, elevated creatinine, leukocytoclastic vasculitis, peripheral edema, photosensitive rash, renal failure (unspecified), somnolence, and visual abnormalities.
[ Last revised: 7/26/2004 5:13:00 PM ]
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