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Acyclovir Side Effects

Not all side effects for acyclovir may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to acyclovir: capsule, powder for solution, solution, suspension, tablet

Other dosage forms:

In addition to its needed effects, some unwanted effects may be caused by acyclovir. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking acyclovir:

More common - For acyclovir injection only
  • Pain, swelling, or redness at place of injection
Less common
  • Abdominal or stomach pain
  • decreased frequency of urination or amount of urine
  • increased thirst
  • loss of appetite
  • nausea or vomiting
  • unusual tiredness or weakness
Rare
  • Black, tarry stools
  • blood in urine or stools
  • chills, fever, or sore throat
  • confusion
  • convulsions (seizures)
  • hallucinations (seeing, hearing, or feeling things that are not there)
  • hives
  • pinpoint red spots on skin
  • trembling
  • unusual bleeding or bruising
Frequency not determined
  • Bleeding or oozing from puncture sites or mucous membranes (bowel, mouth, nose, or urinary bladder), continuing
  • blistering, peeling, or loosening of skin
  • bluish coloring, especially of the hands and feet
  • blurred vision
  • bruising at the place of injection
  • changes in facial skin color
  • changes in vision
  • clumsiness
  • coughing
  • decreased consciousness
  • difficulty in breathing or swallowing
  • dizziness or feeling faint, severe
  • fast heartbeat
  • irritability
  • itching or skin rash
  • large hive-like swelling on face, eyelids, lips, tongue, throat, hands, legs, feet, sex organs
  • mood or mental changes
  • muscle cramps, pain, or weakness
  • pale skin
  • red or irritated eyes
  • sense of agitation or uneasiness
  • shakiness and unsteady walk
  • sores, ulcers, or white spots in mouth or on lips
  • swelling of eyelids, face, feet, hands, lower legs or lips
  • swollen, painful, or tender lymph nodes (glands) in neck, armpit, or groin
  • unsteadiness or other problems with muscle control or coordination
  • yellow eyes or skin

Some of the side effects that can occur with acyclovir may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common - Especially seen with high doses
  • General feeling of discomfort or illness
Less common - Especially seen with long-term use or high doses
  • Diarrhea
  • headache
Frequency not determined
  • Burning, prickling, or tingling sensations
  • drowsiness
  • loss of hair

For Healthcare Professionals

Applies to acyclovir: buccal tablet, compounding powder, intravenous powder for injection, intravenous solution, oral capsule, oral suspension, oral tablet

Gastrointestinal

Gastrointestinal side effects have been the most frequently reported side effects, and include nausea, vomiting, abdominal pain, and diarrhea.

Nausea and vomiting have been reported with oral and intravenous administration, and have preceded neurotoxicity and nephrotoxicity. Gagging and anorexia have also been reported.[Ref]

Renal

Renal side effects have included renal failure, renal pain (may be associated with renal failure), elevated blood urea nitrogen, elevated serum creatinine, and hematuria. Renal effects generally are transient and resolve over several days following discontinuation of therapy; however fatal renal failure has occurred. Renal damage is most commonly due to crystallization of the drug in the renal tubules. Acute tubular necrosis and interstitial nephritis have also been reported.[Ref]

Transient renal dysfunction has been reported with both oral and intravenous acyclovir therapy. Crystallization of the drug in renal tubules is thought to be the mechanism for the development of renal dysfunction, based on findings of crystalluria in several case reports and at least one prospective study.

Elderly or renally impaired patients are at greater risk for developing neurotoxicity and further deterioration in renal function.[Ref]

Nervous system

Nervous system side effects have included aggressive behavior, agitation, ataxia, coma, confusion, decreased consciousness, delirium, delusions, disorientation, dizziness, EEG changes, abnormal cerebrospinal fluid findings, encephalopathy, focal neurological signs, hallucinations, headache, insomnia, irritability, lightheadedness, major depression, mania, myoclonus, obtundation, paresthesia, psychosis, seizure, somnolence, tremors, and Cotard's syndrome. Neurotoxicity generally develops early in acyclovir treatment and has most commonly been reported in patients with renal failure, the elderly, and in patients following bone marrow transplant. It is thought to be associated with high serum concentrations of acyclovir. Guillain Barre syndrome has been reported in at least one patient receiving acyclovir prophylaxis following allogeneic marrow transplantation.[Ref]

Acyclovir neurotoxicity is almost exclusively seen in patients with renal failure. These patients may have longstanding chronic renal failure or acute failure associated with acyclovir. Although more commonly seen with intravenous administration of larger doses, neurotoxicity has also been reported in patients receiving oral doses of acyclovir. Following discontinuation of acyclovir, mental status recovers within about a week. Several patients with chronic renal failure exhibiting neurotoxicity improved dramatically following hemodialysis. In one study of renal transplant patients receiving oral acyclovir therapy, one patient developed neurotoxicity, manifested as disorientation, confusion and myoclonus. The symptoms responded to a decrease in dosage. Three other case reports have also described neurologic symptoms, including visual hallucinations, delusions, mania, tremors, myoclonus and EEG changes, which improved following discontinuation of intravenous acyclovir. Rechallenge in one case using a lower dosage resulted in no sequelae.[Ref]

Local

Local adverse effects associated with intravenous administration of acyclovir have included inflammation or phlebitis at the injection site. Phlebitis is more common when concentrated solutions (greater than 7 mg/mL) are administered. Skin eruptions have been reported at venipuncture sites and tissue necrosis has occurred after infiltration into extravascular tissues.[Ref]

Cardiovascular

Cardiovascular side effects have included hypotension.[Ref]

Dermatologic

Dermatologic side effects have included alopecia, erythema multiforme, hives, photosensitive rash, pruritus, rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, and urticaria.[Ref]

Hematologic

Hematologic and lymphatic side effects have included anemia, disseminated intravascular coagulation, hemolysis, leukocytoclastic vasculitis, leukocytosis, leukopenia, lymphadenopathy, neutropenia, neutrophilia, thrombocytosis, thrombocytopenia, and pancytopenia.[Ref]

Hepatic

Hepatic side effects have included elevated liver function tests, hepatitis, hyperbilirubinemia, and jaundice.[Ref]

Hypersensitivity

Hypersensitivity reactions have included anaphylaxis.[Ref]

Ocular

Ocular side effects have included visual abnormalities.[Ref]

Musculoskeletal

Musculoskeletal side effects reported have included myalgia and dysarthria.[Ref]

Other

Other side effects have included angioedema, fever, malaise, pain, fatigue, peripheral edema, and increased lactate dehydrogenase.[Ref]

Genitourinary

Genitourinary side effects have included crystalluria.[Ref]

References

1. Yang HH, Hsiao YP, Shih HC, Yang JH "Acyclovir-induced neuropsychosis successfully recovered after immediate hemodialysis in an end-stage renal disease patient." Int J Dermatol 46 (2007): 883-4

2. Goldberg LH, Kaufman R, Conant MA, et al "Oral acyclovir for episodic treatment of recurrent genital herpes." J Am Acad Dermatol 15 (1986): 256-64

3. Bean B, Aeppli D "Adverse effects of high-dose intravenous acyclovir in ambulatory patients with acute herpes zoster." J Infect Dis 151 (1985): 362-5

4. Jen SP, Sharma R, Kochar S "Probable acyclovir-induced angioedema in a patient with HIV infection and suspected varicella-zoster virus encephalitis." Am J Health Syst Pharm 68 (2011): 2257-60

5. Krieble BF, Rudy DW, Glick MR, Clayman MD "Case report: acyclovir neurotoxicity and nephrotoxicity--the role for hemodialysis." Am J Med Sci 305 (1993): 36-9

6. Boeckh M, Kim HW, Flowers ME, Meyers JD, Bowden RA "Long-term acyclovir for prevention of varicella zoster virus disease after allogeneic hematopoietic cell transplantation - a randomized double-blind placebo controlled study." Blood 107 (2005): 1800-5

7. Dworkin RH, Johnson RW, Breuer J, et al. "Recommendations for the management of herpes zoster." Clin Infect Dis 44 Suppl 1 (2007): S1-S26

8. Kimberlin DF, Weller S, Whitley R, Andrews WW, Hauth JC, Lakeman F, Miller G "Pharmacokinetics of oral valacyclovir and acyclovir in late pregnancy." Am J Obstet Gynecol 179 (1998): 846-51

9. Tyring S, Belanger R, Bezwoda W, Ljungman P, Boon R, Saltzman RL "A randomized, double-blind trial of famciclovir versus acyclovir for the treatment of localized dermatomal herpes zoster in immunocompromised patients." Cancer Invest 19 (2001): 13-22

10. "Product Information. Zovirax (acyclovir)." Glaxo Wellcome, Research Triangle Park, NC.

11. Cohen SM, Minkove JA, Zebley JW, Mulholland JH "Severe but reversible neurotoxicity from acyclovir." Ann Intern Med 100 (1984): 920

12. Johnson GL, Limon L, Trikha G, Wall H "Acute renal failure and neurotoxicity following oral acyclovir." Ann Pharmacother 28 (1994): 460-3

13. Roling J, Schmid H, Fischereder M, Draenert R, Goebel FD "HIV-Associated Renal Diseases and Highly Active Antiretroviral Therapy-Induced Nephropathy." Clin Infect Dis 42 (2006): 1488-95

14. Rashed A, Asadeh B, Romeh SHA "Acyclovir-induced acute tubulo-interstitial nephritis." Nephron 56 (1990): 436-8

15. Lopez PF, Davis JL, Pare R, Kinota S, Lambert HM "Acyclovir induced renal failure in the treatment of presumed viral retinitis." Ann Ophthalmol 27 (1995): 75-84

16. Hernandez JO, Norstrom J, Wysock G "Acyclovir-induced renal failure in an obese patient." Am J Health Syst Pharm 66 (2009): 1288-91

17. Lawson AF, Green PA, Brett AS "Acute renal insufficiency due to oral acyclovir in a man with sickle cell trait." South Med J 92 (1999): 1093-4

18. Straus SE, Dale JK, Tobi M, et al "Acyclovir treatment of the chronic fatigue syndrome: lack of efficacy in a placebo-controlled trial." N Engl J Med 319 (1988): 1692-8

19. Fletcher CV, Chinnock BJ, Chace B, Balfour HH "Pharmacokinetics and safety of high-dose oral acyclovir for suppression of cytomegalovirus disease after renal transplantation." Clin Pharmacol Ther 44 (1988): 158-63

20. Bianchetti MG, Roduit C, Oetliker OH "Acyclovir-induced renal failure: course and risk factors." Pediatr Nephrol 5 (1991): 238-9

21. Hernandez E, Praga M, Moreno F, Montoyo C "Acute renal failure induced by oral acyclovir." Clin Nephrol 36 (1991): 155-6

22. Becker BN, Fall P, Hall C, Milam D, Leonard J, Glick A, Schulman G "Rapidly progressive acute renal failure due to acyclovir: case report and review of the literature." Am J Kidney Dis 22 (1993): 611-5

23. Peterslund NA, Larsen ML, Mygind H "Acyclovir crystalluria." Scand J Infect Dis 20 (1988): 225-8

24. Izzedine H, Launay-Vacher V, Deray G "Antiviral drug-induced nephrotoxicity." Am J Kidney Dis 45 (2005): 804-17

25. Sawyer MH, Webb DE, Balow JE, Straus SE "Acyclovir-induced renal failure." Am J Med 84 (1988): 1067-71

26. Mason WJ, Nickols HH "Images in clinical medicine. Crystalluria from acyclovir use." N Engl J Med 358 (2008): e14

27. Gnann JW, Barton NH, Whitley RJ "Acyclovir: mechanism of action, pharmacokinetics, safety and clinical applications." Pharmacotherapy 3 (1983): 275-83

28. Perazella MA "Drug-induced renal failure: update on new medications and unique mechanisms of nephrotoxicity." Am J Med Sci 325 (2003): 349-62

29. Adair JC, Gold M, Bond RE "Acyclovir neurotoxicity: clinical experience and review of the literature." South Med J 87 (1994): 1227-31

30. Rashiq S, Briewa L, Mooney M, Giancarlo T, Khatib R, Wilson FM "Distinguishing acyclovir neurotoxicity from encephalomyelitis." J Intern Med 234 (1993): 507-11

31. Hellden A, Odar-Cederlof I, Larsson K, Fehrman-Ekholm I, Linden T "Death delusion." BMJ 335 (2007): 1305

32. Jones PG, Beier-Hanratty SA "Acyclovir: neurologic and renal toxicity." Ann Intern Med 104 (1986): 892

33. Ernst ME, Franey RJ "Acyclovir- and ganciclovir-induced neurotoxicity." Ann Pharmacother 32 (1998): 111-3

34. Wade JC, Meyers JD "Neurologic symptoms associated with parenteral acyclovir treatment after marrow transplantation." Ann Intern Med 98 (1983): 921-5

35. MacDiarmaid-Gordon AR, O'Connor M, Beaman M, Ackrill P "Neurotoxicity associated with oral acyclovir in patients undergoing dialysis." Nephron 62 (1992): 280-3

36. Beales P, Almond MK, Kwan JTC "Acyclovir neurotoxicity following oral therapy - prevention and treatment in patients on haemodialysis." Nephron 66 (1994): 362-3

37. Mataix AL, Duarte J, Revuelta K, et al. "Oral acyclovir and neurologic adverse effects in endstage renal disease." Ann Pharmacother 28 (1991): 961-2

38. Slifkin M, Doron S, Snydman DR "Viral prophylaxis in organ transplant patients." Drugs 64 (2004): 2763-92

39. Papadakis M, Fee P, Wilhelm T, Davenport A, Connolly J "Facial weakness in a haemodialysis patient." Lancet 369 (2007): 714

40. Feldman S, Rodman J, Gregory B "Excessive serum concentrations of acyclovir and neurotoxicity." J Infect Dis 157 (1988): 385-8

41. Fukunishi I, Inada T, Horie Y "Manic symptoms caused by acyclovir in a hemodialysis patient." Nephron 67 (1994): 494

42. Gill MJ, Burgess E "Neurotoxicity of acyclovir in end stage renal disease." J Antimicrob Chemother 25 (1990): 300-1

43. Sylvester RK, Ogden WB, Draxler CA, Lewis B "Vesicular eruption: a local complication of concentrated acyclovir infusions." JAMA 255 (1986): 385-6

44. Tomson CR, Goodship TH, Rodger RS "Psychiatric side-effects of acyclovir in patients with chronic renal failure." Lancet 2 (1985): 385-6

45. Mindel A, Carney O. Freris M, Faherty A, Patou G, Williams P "Dosage and safety of long-term suppressive acyclovir therapy for recurrent genital herpes." Lancet Apr (1988): 926-8

46. Fazal BA, Turett GS, Justman JE, Hall G, Telzak EE "Stevens-johnson syndrome induced by treatment with acyclovir." Clin Infect Dis 21 (1995): 1038-9

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