More frequently reported side effects include: nausea, phlebitis, vomiting, and inflammation at injection site. See below for a comprehensive list of adverse effects.
Applies to acyclovir: capsule, powder for solution, solution, suspension, tablet
Other dosage forms:
Along with its needed effects, acyclovir may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking acyclovir:
More common- For acyclovir injection only
Frequency not determined
Some side effects of acyclovir may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common- Especially seen with high doses
Less common- Especially seen with long-term use or high doses
Frequency not determined
Applies to acyclovir: buccal tablet, compounding powder, intravenous powder for injection, intravenous solution, oral capsule, oral suspension, oral tablet
The more commonly reported adverse reactions include malaise, nausea, vomiting, diarrhea, and headache.
Nausea and vomiting are more frequent in elderly subjects.
Common (1% to 10%): Nausea, vomiting, diarrhea, abdominal pain, gingival pain (buccal tablet), aphthous stomatitis (buccal tablet)
Uncommon (0.1% to 1%): Sore throat
Postmarketing reports: Gastrointestinal distress
Rare (0.01% to 0.1%): Elevated blood urea nitrogen, elevated creatinine,
Very rare (less than 0.01%): Acute renal failure, renal pain
Frequency not reported: Crystalluria, renal impairment
Postmarketing reports: Renal failure, hematuria
Renal pain may be associated with renal failure and crystalluria. Renal impairment is generally reversible but may progress to acute renal failure.
Common (1% to 10%): Application site pain and application site irritation, local inflammation at injection site, phlebitis
Frequency not reported: Tissue necrosis
Severe local inflammatory reactions, including tissue necrosis, have occurred following infusion into extravascular tissues. Application site pain and application site irritation have occurred with the buccal tablets.
Dizziness, somnolence, and coma more frequent in elderly subjects.
Common (1% to 10%): Headache, dizziness
Very rare (less than 0.01%): Ataxia, coma, convulsions, encephalopathy, dysarthria
Frequency not reported: Giddiness, shaking, taste disturbance, medication taste
Postmarketing reports: Decreased consciousness, delirium, paresthesia, seizure, tremors
Common (1% to 10%): Erythema, rashes (including photosensitivity), pruritus, hives
Uncommon (0.1% to 1%): Urticaria, accelerated diffuse hair loss
Frequency not reported: Diaphoresis
Postmarketing reports: Alopecia, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis
Frequency not reported: Palpitation, chest pain
Postmarketing reports: Hypotension, peripheral edema
Very rare (less than 0.01%): Anemia, leukopenia, thrombocytopenia, neutropenia
Frequency not reported: Hematologic changes including megaloblastic anemia
Postmarketing reports: Leukocyclastic vasculitis, lymphadenopathy, disseminated intravascular coagulation, hemolysis
Rare (0.01% to 0.1%): Reversible bilirubin and liver related enzymes
Very rare (less than 0.01%): Hepatitis, jaundice
Postmarketing reports: Hyperbilirubinemia
Rare (0.01% to 0.1%): Anaphylaxis
Frequency not reported: Angioedema
Frequency not reported: Pars planitis
Postmarketing reports: Visual abnormalities
Uncommon (0.1% to 1%): Leg pain
Postmarketing reports: Myalgia
Common (1% to 10%): Lethargy, fatigue, fever
Frequency not reported: Vertigo
Postmarketing reports: Fever
Frequency not reported: Menstrual abnormalities, abnormal urinalysis (characterized by an increase in formed elements in urine sediment) anuria, dysuria, hematuria
Uncommon (0.1% to 1%): Anorexia
Frequency not reported: Thirst
Hallucinations, psychosis, confusion, aggressive behavior, agitation may be more marked in older adults and those with renal impairment.
Very rare (less than 0.01%): Agitation, confusion, hallucinations, psychotic symptoms
Frequency not reported: Depression, insomnia
Postmarketing reports: Aggressive behavior
Rare (0.01% to 0.1%): Dyspnea
Medically reviewed by BestRx Medical Team Last updated on 1/1/2020.
Source: Drugs.com Acyclovir