Abacavir Side Effects

Not all side effects for abacavir 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 abacavir: oral solution, oral tablet

In addition to its needed effects, some unwanted effects may be caused by abacavir. 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 abacavir:

Less common
  • Abdominal or stomach pain
  • cough
  • diarrhea
  • difficult or labored breathing
  • fever
  • headache
  • joint or muscle pain
  • nausea
  • numbness or tingling of the hands, feet, or face
  • redness and soreness of the eyes
  • skin rash
  • sore throat
  • sores in the mouth
  • swelling of the feet or lower legs
  • unusual feeling of discomfort or illness
  • unusual tiredness
  • vomiting
  • Abdominal or stomach swelling
  • decreased appetite
  • fast, shallow breathing
  • sleepiness
Incidence not known
  • Blistering, peeling, or loosening of the skin
  • chest pain or discomfort
  • chills
  • dark urine
  • itching
  • light-colored stools
  • pain or discomfort in the arms, jaw, back, or neck
  • red, irritated eyes
  • red skin lesions, often with a purple center
  • sores, ulcers, or white spots in the mouth or on the lips
  • sweating
  • unusual weakness
  • upper right abdominal or stomach pain
  • yellow eyes and skin

Some of the side effects that can occur with abacavir 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
  • Headache
Less common
  • Trouble sleeping
Incidence not known
  • Breast enlargement
  • buffalo hump
  • central obesity
  • facial wasting
  • gaining weight around your neck, upper back, breast, face, or waist
  • peripheral wasting

For Healthcare Professionals

Applies to abacavir: oral solution, oral tablet


Patients receiving once-daily abacavir had a significantly higher incidence of severe hypersensitivity reactions and severe diarrhea than patients on the twice-daily regimen.[Ref]


Common (1% to 10%): Drug hypersensitivity (Grades 2 to 4; 9%), hypersensitivity reaction (Grades 2 to 4; 8%)
Rare (less than 0.1%): Abacavir hypersensitivity reaction presenting as acute fibrinous and organizing pneumonia (at least 1 case)
Frequency not reported: Serious and sometimes fatal hypersensitivity reactions (including fever, skin rash [maculopapular, urticarial, or variable appearance], malaise, fatigue, achiness, nausea, vomiting, diarrhea, abdominal pain, pharyngitis, dyspnea, cough, lethargy, myolysis, edema, abnormal chest X-ray [infiltrates], paresthesia, anaphylaxis, liver failure, renal failure, hypotension, adult respiratory distress syndrome, respiratory failure, death, lymphadenopathy, mucous membrane lesions [conjunctivitis and stomatitis], elevated liver function tests, elevated creatine phosphokinase, elevated creatinine, lymphopenia)[Ref]

Serious and sometimes fatal hypersensitivity reactions have been reported. Frequently observed signs and symptoms have included, but were not limited to, fever, skin rash (maculopapular, urticarial, or variable appearance), malaise, fatigue, achiness, nausea, vomiting, diarrhea, abdominal pain, pharyngitis, dyspnea, and cough. Other symptoms of abacavir hypersensitivity have included lethargy, myolysis, edema, abnormal chest X-ray (infiltrates), paresthesia, anaphylaxis, liver failure, renal failure, hypotension, adult respiratory distress syndrome, respiratory failure, death, lymphadenopathy, mucous membrane lesions (conjunctivitis and stomatitis), elevated liver function tests, elevated creatine phosphokinase, elevated creatinine, and lymphopenia.

In one case report a 57-year-old HIV positive male presented to medical attention with a 2-day history of fever, malaise, and diarrhea related to initiation of abacavir. Six days prior to the onset of symptoms the patient's antiretroviral therapy was switched from efavirenz and lamivudine-zidovudine to zidovudine, abacavir, and lopinavir-ritonavir after a drop in his CD4 cell count. The patient developed acute dyspnea and severe hypoxemia, hemoptysis, and diffuse bilateral pulmonary infiltrates within 72 hours of admission and abacavir was discontinued due to suspicion of a hypersensitivity reaction. Three days following discontinuation of abacavir the patient's status improved and chest films showed resolution of infiltrates.

Abacavir hypersensitivity is a clinical syndrome affecting multiple organs generally characterized by a sign or symptom in two or more of the following groups:
(1) Fever
(2) Rash
(3) Gastrointestinal (including nausea, vomiting, diarrhea, or abdominal pain)
(4) Constitutional (including generalized malaise, fatigue, or achiness)
(5) Respiratory (including dyspnea, cough, or pharyngitis)

A strong predictor of hypersensitivity reaction may be the presence of human leukocyte antigen subtype B*5701 (HLA-B*5701). Analyzing past studies, patients testing positive for the HLA-B*5701 allele had a greater risk (61% to about 70%) of developing hypersensitivity reactions with abacavir, while patients without the HLA-B*5701 allele had a low risk (less than 1% to 4%); therefore, screening for the HLA-B*5701 allele is recommended prior to starting abacavir treatment. Therapy with an abacavir-containing regimen is not recommended for HLA-B*5701-positive patients and should be considered only with close medical supervision under exceptional conditions where potential benefit outweighs the risk. Considerably less frequently, HLA-B*5701-negative patients may experience hypersensitivity reaction with abacavir.

Abacavir should be permanently discontinued as soon as a hypersensitivity reaction is suspected. Severe or fatal hypersensitivity reactions can also occur within hours after restarting abacavir in patients who have no identified history or unrecognized symptoms of this reaction. It should be permanently discontinued if hypersensitivity cannot be ruled out, even when other diagnoses are possible, to minimize the risk of a life-threatening hypersensitivity reaction.[Ref]


The reported frequencies were similar to those observed during clinical trials with zidovudine and lamivudine administration.

Increased gamma-glutamyltransferase was observed in the expanded access program.

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs alone or in combination with other antiretroviral agents.[Ref]

Common (1% to 10%): Elevated ALT (greater than 5 times ULN; 6%), elevated AST (greater than 5 times ULN; up to 6%)
Frequency not reported: Increased gamma-glutamyltransferase, severe hepatomegaly with steatosis
Postmarketing reports: Lactic acidosis, hepatic steatosis[Ref]


Pancreatitis was observed in the expanded access program.[Ref]

Very common (10% or more): Nausea (at least moderate intensity: up to 19%), nausea and vomiting (at least moderate intensity: 10%)
Common (1% to 10%): Diarrhea (at least moderate intensity: 7%), abdominal pain/gastritis/gastrointestinal signs and symptoms (at least moderate intensity: 6%), vomiting (at least moderate intensity: 2%)
Frequency not reported: Loss of appetite/anorexia, pancreatitis[Ref]

Nervous system

Very common (10% or more): Headache (at least moderate intensity: 13%)
Common (1% to 10%): Headaches/migraine (at least moderate intensity: 7%), dizziness (at least moderate intensity: 6%)
Frequency not reported: Insomnia, other sleep disorders[Ref]


Very common (10% or more): Malaise and fatigue (at least moderate intensity: 12%)
Common (1% to 10%): Fatigue/malaise (at least moderate intensity: 7%), fever and/or chills (at least moderate intensity: 6%), ear/nose/throat infections (at least moderate intensity: 5%)
Uncommon (0.1% to 1%): Non-site-specific pain (at least moderate intensity: less than 1%)
Frequency not reported: Asthenia, reduced alcohol tolerance, disulfiram-like reaction[Ref]

In one case report, a 31-year-old HIV-infected male patient switched to abacavir and experienced a disulfiram-like reaction with nausea, facial flushing, and tachycardia following alcohol consumption. When the patient was rechallenged with a shot of vodka, the same reaction occurred.

In another case, a 27-year-old HIV-infected male patient switched to abacavir and noticed reduced alcohol tolerance. The patient reported that he felt as if he had ingested 1.5 bottles of wine following 3 glasses, with loss of memory until the next morning and vomiting. The patient was able to tolerate small quantities of alcohol or alcohol consumed with food.[Ref]


Very common (10% or more): Dreams/sleep disorders (at least moderate intensity: 10%)
Common (1% to 10%): Depressive disorders (at least moderate intensity: 6%), anxiety (at least moderate intensity: 5%)
Frequency not reported: Mania, worsening of preexisting depression, lethargy[Ref]


Common (1% to 10%): Rashes (at least moderate intensity: 6%), skin rashes (at least moderate intensity: 5%)
Frequency not reported: Sweet's syndrome
Postmarketing reports: Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme[Ref]

Suspected Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported in patients receiving abacavir primarily in combination with medications known to be associated with SJS and TEN, respectively. Due to overlap of clinical signs and symptoms between abacavir hypersensitivity and SJS and TEN, and the possibility of multiple drug sensitivities in some patients, abacavir should be permanently discontinued in such cases.[Ref]


Common (1% to 10%): Elevated creatine phosphokinase (greater than 4 times ULN; up to 8%), hypertriglyceridemia (greater than 750 mg/dL; up to 6%), hyperamylasemia (greater than 2 times ULN; up to 4%)
Uncommon (0.1% to 1%): Hyperglycemia (greater than 13.9 mmol/L; less than 1%)
Rare (less than 0.1%): Hypoglycemia (at least 1 case)
Frequency not reported: Mild elevations of blood glucose
Postmarketing reports: Redistribution/accumulation of body fat (including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement, "cushingoid appearance")[Ref]


The reported frequencies were similar to those observed during clinical trials with zidovudine and lamivudine administration.

Agranulocytosis has been reported after the addition of abacavir to a multi-drug regimen.[Ref]

Common (1% to 10%): Neutropenia (ANC less than 750/mm3; up to 5%), thrombocytopenia (platelets less than 50,000/mm3; 1%)
Uncommon (0.1% to 1%): Anemia (Hgb 6.9 g/dL or less; less than 1%), leukopenia (WBC 1500/mm3 or less; less than 1%)
Rare (less than 0.1%): Eosinophilia
Frequency not reported: Agranulocytosis, increased platelet reactivity[Ref]


Common (1% to 10%): Musculoskeletal pain (at least moderate intensity: up to 6%)[Ref]


Frequency not reported: Immune reconstitution syndrome, autoimmune disorders in the setting of immune reconstitution (e.g., Graves' disease, polymyositis, and Guillain-Barre syndrome)


Common (1% to 10%): Viral respiratory infections (at least moderate intensity: 5%), bronchitis (at least moderate intensity: 4%)
Frequency not reported: Tachypnea, cough, pharyngitis[Ref]


A study investigating the frequency of myocardial infarction (MI) in patients taking combination antiretroviral treatment showed an increased risk of MI with the use of abacavir within the previous 6 months; however, these results are not conclusive. The manufacturer reviewed its own clinical study databases and although the results of the analysis are inconclusive, they did not show an excess risk of MI. A meta-analysis conducted by the FDA showed no statistically significant difference in MI events between patients who received abacavir and those who did not.[Ref]

Rare (less than 0.1%): Peripheral arterial disease (at least 2 cases), coronary bypass surgery (at least 1 case), ischemic stroke (at least 1 case), deep venous thrombosis (at least 1 case), angina (at least 1 case), transient ischemic attack (at least 1 case)
Frequency not reported: Endothelial dysfunction
Postmarketing reports: Myocardial infarction[Ref]


Uncommon (0.1% to 1%): Renal signs/symptoms (at least moderate intensity: less than 1%)
Frequency not reported: Acute renal failure, interstitial nephritis[Ref]


1. AIDSinfo. NIH. National Institutes of Health "Guidelines for the use of antiretroviral agents in pediatric HIV infection. Available from: URL: http://aidsinfo.nih.gov/contentfiles/lvguidelines/pediatricguidelines.pdf." ([2015 Mar 5]):

2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

3. Warnke D, Barreto J, Temesgen Z "Antiretroviral drugs." J Clin Pharmacol 47 (2007): 1570-9

4. Calza L, Dentale N, Piergentili B, et al. "Abacavir-induced febrile agranulocytosis and anaemia." AIDS 22 (2008): 2221-2

5. "Product Information. Ziagen (abacavir)." Glaxo Wellcome, Research Triangle Pk, NC.

6. Cerner Multum, Inc. "Australian Product Information." O 0

7. Piacenti FJ "An update and review of antiretroviral therapy." Pharmacotherapy 26 (2006): 1111-33

8. HHS Panel on Antiretroviral Guidelines for Adults and Adolescents. Office of AIDS Research Advisory Council (OARAC). NIH. National Institutes of Health "Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents. Available from: URL: http://aidsinfo.nih.gov/contentfiles/lvguidelines/adultandadolescentgl.pdf." ([2015 Apr 8]):

9. Bart PA, Rizzardi GP, Tambussi G, Chave JP, Chapuis AG, Graziois C, Corpataux JM, Halkic N, Meuwly JY, Munoz M, Meylan P, "Immunological and virological responses in HIV-1-infected adults at early stage of established infection treated with highly active antiretroviral therapy." Aids 14 (2000): 1887-97

10. Peyriere H, Dereure O, Breton H, et al. "Variability in the clinical pattern of cutaneous side-effects of drugs with systemic symptoms: does a DRESS syndrome really exist?" Br J Dermatol 155 (2006): 422-8

11. Hetherington S, McGuirk S, Powell G, et al. "Hypersensitivity reactions during therapy with the nucleoside reverse transcriptase inhibitor abacavir." Clin Ther 23 (2001): 1603-14

12. Waters LJ, Mandalia S, Gazzard B, Nelson M "Prospective HLA-B*5701 screening and abacavir hypersensitivity: a single centre experience." AIDS 21 (2007): 2533-2534

13. "Drugs for HIV infection." Med Lett Drugs Ther 43 (2001): 103-8

14. Cutrell AG, Hernandez JE, Fleming JW, et al. "Updated clinical risk factor analysis of suspected hypersensitivity reactions to abacavir." Ann Pharmacother 38 (2004): 2171-2

15. Abel S, Paturel L, Cabie A "Abacavir hypersensitivity." N Engl J Med 358 (2008): 2515; author reply 2515-6

16. Goedken AM, Herman RA "Once-daily abacavir in place of twice-daily administration." Ann Pharmacother 39 (2005): 1302-8

17. Chen SJ, Yang SP, Hung CC, Fung CP "Abacavir-induced agranulocytosis in two Taiwanese patients tested HLA-B*5701-negative." AIDS 24 (2010): 1238-9

18. Fox J, Newton P, Daly R, et al. "An unusual abacavir reaction." AIDS 22 (2008): 1520-2

19. Phillips EJ "Genetic screening to prevent abacavir hypersensitivity reaction: are we there yet?" Clin Infect Dis 43 (2006): 103-5

20. "Drugs for HIV infection." Treat Guidel Med Lett 7 (2009): 11-22

21. Bergersen BM "Cardiovascular Risk in Patients with HIV Infection : Impact of Antiretroviral Therapy." Drugs 66 (2006): 1971-87

22. Yokogawa N, Alcid DV "Acute fibrinous and organizing pneumonia as a rare presentation of abacavir hypersensitivity reaction." AIDS 21 (2007): 2116-2117

23. Strategies for Management of Anti-RetroviralTherapy/Insight; DAD Study Groups "Use of nucleoside reverse transcriptase inhibitors and risk of myocardial infarction in HIV-infected patients." AIDS 22 (2008): F17-F24

24. de Perio MA, Gomez FJ, Frame PT, Fichtenbaum CJ "A truvada hypersensitivity reaction simulating abacavir hypersensitivity." AIDS 21 (2007): 2252-3

25. Toerner JG, Cvetkovich T "Kawasaki-like Syndrome: Abacavir Hypersensitivity?" Clin Infect Dis 34 (2002): 131-2

26. Yuen GJ, Weller S, Pakes GE "A Review of the Pharmacokinetics of Abacavir." Clin Pharmacokinet 47 (2008): 351-371

27. Anderson PL "Pharmacologic perspectives for once-daily antiretroviral therapy." Ann Pharmacother 38 (2004): 1969-70

28. Loeliger AE, Steel H, McGuirk S, Powell WS, Hetherington SV "The abacavir hypersensitivity reaction and interruptions in therapy." Aids 15 (2001): 1325

29. Borras-Blasco J, Navarro-Ruiz A, Borras C, Castera E "Adverse cutaneous reactions associated with the newest antiretroviral drugs in patients with human immunodeficiency virus infection." J Antimicrob Chemother 62 (2008): 879-88

30. Rauch A, Nolan D, Martin A, McKinnon E, Almeida C, Mallal S "Prospective genetic screening decreases the incidence of abacavir hypersensitivity reactions in the Western Australian HIV cohort study." Clin Infect Dis 43 (2006): 99-102

31. Bonta PI, Vermeulen JN, Speelman P, Prins JM "Severe abacavir hypersensitivity reaction in a patient tested HLA-B*5701 negative." AIDS 22 (2008): 1522-3

32. Herring SJ, Krieger AC "Acute respiratory manifestations of the abacavir hypersensitivity reaction." AIDS 20 (2006): 301-2

33. Stekler J, Maenza J, Stevens C, et al. "Abacavir hypersensitivity reaction in primary HIV infection." AIDS 20 (2006): 1269-74

34. Vandekerckhove L, Blot S "Abacavir hypersensitivity." N Engl J Med 358 (2008): 2514-5; author reply 2515-6

35. Hammer SM, Saag MS, Schechter M, et al. "Treatment for adult HIV infection: 2006 recommendations of the International AIDS Society-USA panel." JAMA 296 (2006): 827-43

36. Hervey PS, Perry CM "Abacavir - A review of its clinical potential in patients with HIV infection." Drugs 60 (2000): 447-79

37. Fontaine C, Guiard-Schmid JB, Slama L, et al. "Severe rhabdomyolysis during a hypersensitivity reaction to abacavir in a patient treated with ciprofibrate." AIDS 19 (2005): 1927-8

38. Tozzi V "Pharmacogenetics of antiretrovirals." Antiviral Res 85 (2010): 190-200

39. Hughes CA, Foisy MM, Dewhurst N, et al. "Abacavir hypersensitivity reaction: an update." Ann Pharmacother 42 (2008): 387-96

40. Soriano V, Puoti M, Sulkowski M, et al. "Care of patients coinfected with HIV and hepatitis C virus: 2007 updated recommendations from the HCV-HIV International Panel." AIDS 21 (2007): 1073-89

41. Soni S, Churchill DR, Gilleece Y "Abacavir-induced hepatotoxicity: a report of two cases." AIDS 22 (2008): 2557-8

42. Barber TJ, Marett B, Waldron S, et al. "Are disulfiram-like reactions associated with abacavir-containing antiretroviral regimens in clinical practice?" AIDS 21 (2007): 1823-1824

43. Del Giudice P, Vandenbos F, Perrin C, Bernard E, Marq L, Dellamonica P "Sweet's syndrome following abacavir therapy." J Am Acad Dermatol 51 (2004): 474-5

44. Larios OE, Kasper K, Becker ML "First report of abacavir associated with hypoglycemia." AIDS 24 (2010): 2138-9

45. Sankatsing SU, Prins JM "Agranulocytosis and fever seven weeks after starting abacavir." AIDS 15 (2001): 2464-5

46. Hsue PY, Hunt PW, Wu Y, et al. "Association of abacavir and impaired endothelial function in treated and suppressed HIV-infected patients." AIDS 23 (2009): 2021-7

47. Satchell CS, O'Halloran JA, Cotter AG, et al. "Increased Platelet Reactivity in HIV-1-Infected Patients Receiving Abacavir-Containing Antiretroviral Therapy." J Infect Dis 204 (2011): 1202-10

48. Bedimo RJ, Westfall AO, Drechsler H, Vidiella G, Tebas P "Abacavir use and risk of acute myocardial infarction and cerebrovascular events in the highly active antiretroviral therapy era." Clin Infect Dis 53 (2011): 84-91

49. Cruciani M, Zanichelli V, Serpelloni G, et al. "ABACAVIR use and cardiovascular disease events: a meta-analysis of published and unpublished data." AIDS 25 (2011): 1993-2004

50. Calza L, Manfredi R, Verucchi G "Myocardial infarction risk in HIV-infected patients: epidemiology, pathogenesis, and clinical management." AIDS 24 (2010): 789-802

51. Ribaudo HJ, Benson CA, Zheng Y, et al. "No Risk of Myocardial Infarction Associated With Initial Antiretroviral Treatment Containing Abacavir: Short and Long-Term Results from ACTG A5001/ALLRT." Clin Infect Dis 52 (2011): 929-940

52. 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

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.