Retrovir Side Effects

Generic Name: zidovudine

Note: This page contains side effects data for the generic drug zidovudine. It is possible that some of the dosage forms included below may not apply to the brand name Retrovir.

It is possible that some side effects of Retrovir may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

For the Consumer

Applies to zidovudine: oral capsule, oral syrup, oral tablet

Other dosage forms:

As well as its needed effects, zidovudine (the active ingredient contained in Retrovir) may cause unwanted side effects that require medical attention.

If any of the following side effects occur while taking zidovudine, check with your doctor immediately:

More common
  • Fever, chills, or sore throat
  • pale skin
  • unusual tiredness or weakness
  • Abdominal or stomach discomfort
  • confusion
  • convulsions (seizures)
  • diarrhea
  • fast, shallow breathing
  • general feeling of discomfort
  • loss of appetite
  • mood or mental changes
  • muscle pain, tenderness, weakness, or cramping
  • nausea
  • shortness of breath
  • sleepiness

Some zidovudine side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common
  • Difficulty having a bowel movement (stool)
  • general feeling of discomfort or illness
  • headache (severe)
  • lack or loss of strength
  • muscle soreness
  • trouble with sleeping
  • vomiting
  • weight loss
Less common
  • Bluish-brown colored bands on nails
  • changes in skin color
Incidence not known
  • Acid or sour stomach
  • belching
  • burning, tingling, numbness, or pain in the hands, arms, feet, or legs
  • heartburn
  • indigestion
  • muscle or bone pain
  • sensation of pins and needles, stabbing pain
  • stomach cramps
  • stomach pain
  • yellow eyes or skin

For Healthcare Professionals

Applies to zidovudine: intravenous solution, oral capsule, oral syrup, oral tablet


The adverse effects of zidovudine (the active ingredient contained in Retrovir) are sometimes difficult to distinguish from the symptomatology observed during the clinical course of AIDS, as well as from the possible adverse effects of other drugs used in the treatment of HIV-1 infection. Many of the side effects associated with nucleoside reverse transcriptase inhibitor therapy (myopathy, pancreatitis, liver failure, lactic acidosis, etc.) are attributable to their direct toxic effect on mitochondria which causes decreased mitochondrial energy-generating capacity.

Nervous system

Nervous system side effects have included headache (up to 63%), insomnia (5% or greater), neuropathy (5% or greater), and numbness. Status epilepticus and Wernicke's syndrome have been rarely reported. Seizures, confusion, dizziness, paresthesia, somnolence, vertigo, hearing loss, and loss of mental acuity have been reported during postmarketing experience.


Bone marrow suppression, the most common reason for cessation of zidovudine (the active ingredient contained in Retrovir) therapy, appears to be dose-dependent and may be seen as early as 2 to 6 weeks after initiation of therapy. Recombinant GM-CSF (sargramostim), G-CSF (filgrastim), and erythropoietin (epoetin alfa) have been used to control the hematologic toxicity of zidovudine.

Zidovudine should be used with extreme caution in patients with bone marrow suppression indicated by a granulocyte count below 1000 cells/mm3 or hemoglobin less than 9.5 g/dL. Routine blood counts are recommended, and generally should occur more frequently in patients with advanced disease. If bone marrow toxicity occurs, an interruption or discontinuation of zidovudine therapy may be necessary.

Hematologic side effects have included granulocytopenia (less than 750 cells/mm3; up to 2%), anemia (hemoglobin less than 8 g/dL; up to 1.1%), and increased hemoglobin A2 percentage. Hematologic toxicity, including neutropenia and severe anemia, has been reported, mostly in patients with advanced HIV-1 disease. Exacerbation of anemia due to ribavirin has been reported when zidovudine was part of the HIV-1 regimen. Aplastic anemia, hemolytic anemia, leukopenia, lymphadenopathy, pancytopenia with marrow hypoplasia, and pure red cell aplasia have been reported during postmarketing experience.


Gastrointestinal side effects have included nausea (up to 51.4%), anorexia (up to 20.1%), vomiting (up to 17.2%), constipation (up to 6.4%), dyspepsia (5% or greater), abdominal cramps (5% or greater), abdominal pain (5% or greater), diarrhea, stomatitis, and splenomegaly. Dysphagia, constipation, flatulence, oral mucosa pigmentation, mouth ulcer, and pancreatitis have been reported during postmarketing experience.


Hepatic side effects have included increased ALT (greater than 5 times ULN; up to 3.1%) and AST (greater than 5 times ULN; up to 1%), hyperbilirubinemia (less than or equal to 0.8%), fulminate hepatitis, and hepatic failure. Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs alone or in combination, including zidovudine (the active ingredient contained in Retrovir) and other antiretrovirals. Hepatic decompensation (some fatal) has been reported in patients coinfected with HIV-1 and hepatitis C receiving combination antiretroviral therapy for HIV-1 and interferon alfa with or without ribavirin. Hepatitis, hepatomegaly with steatosis, lactic acidosis, and jaundice have been reported during postmarketing experience.

One patient with preexisting hepatitis B developed acute hepatic failure two weeks after starting zidovudine therapy.

Patients with a history of liver disease should be monitored for further deterioration in liver function.


In one case of zidovudine-associated fever, no source of infection was found after an extensive evaluation, but an anti-zidovudine (the active ingredient contained in Retrovir) immunoglobulin was isolated, indicating a possible hypersensitivity reaction.

Other side effects have included malaise (up to 53.2%), asthenia (up to 9%), fatigue (5% or greater), chills (5% or greater), and fever. Zidovudine therapy has been associated with lower levels of vitamins B2 and C, folate, and zinc despite adequate dietary intake. Back pain, chest pain, influenza-like syndrome, generalized pain, syncope, and taste perversion have been reported during postmarketing experience.


In one study, myalgias and elevated creatine kinase occurred in 8% of treated patients with a CD4 cell count less than 200/mm3, and in none of the patients with higher CD4 cell counts. Dosage reduction has not affected the course of myopathy, although drug discontinuation sometimes resulted in improvement of symptoms, generally within a month. Muscle biopsy has shown atrophic and sometimes necrotic fibers, ragged-red fibers, and large accumulations of mitochondrial and fibrillar sarcoplasmic inclusions.

Myopathy and myositis with pathological changes, similar to that produced by HIV-1 disease, have been associated with prolonged use of zidovudine (the active ingredient contained in Retrovir)

Musculoskeletal side effects have included arthralgia, myalgia, and musculoskeletal pain in greater than or equal to 5% of patients. Myopathy, myositis, muscle tenderness, and weakness in the arms and legs have been reported and were generally associated with an elevation in serum creatine kinase. Increased creatine phosphokinase, muscle spasm, myopathy and myositis with pathological changes (similar to that produced by HIV-1 disease), rhabdomyolysis, and tremor have been reported during postmarketing experience.


Psychiatric side effects have included isolated cases of depression, mania, anxiety, and grandiosity. Anxiety, depression, and mania have been reported during postmarketing experience.


Dermatologic side effects have included case reports of nailbed hyperpigmentation, particularly in black people. Rarely, nail hyperpigmentation has been accompanied by mucocutaneous pigmentation or hypertrichosis. Skin rashes and leukocytoclastic vasculitis with eosinophilia and fever have also been reported. Changes in skin and nail pigmentation, pruritus, rash, Stevens-Johnson syndrome, toxic epidermal necrolysis, sweat, and urticaria have been reported during postmarketing experience.

Bluish or brownish-black discoloration of nails has developed during the first month or two of zidovudine therapy and usually disappeared within 2 months if the drug was discontinued. Discoloration has occurred as longitudinal streaks or transverse bands.


Cardiovascular side effects have included rare cases of reversible congestive heart failure and vasodilation. Cardiomyopathy and vasculitis have been reported during postmarketing experience.


Hypersensitivity side effects have included allergic skin rash. Sensitization reactions including anaphylaxis and angioedema have been reported during postmarketing experience.


Metabolic side effects have included hyperlipidemia. Redistribution/accumulation of body fat including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement, and "cushingoid appearance" have been observed in patients receiving antiretroviral therapy. Increased lactate dehydrogenase and redistribution/accumulation of body fat have been reported during postmarketing experience.


Respiratory side effects have included cough, dyspnea, rhinitis, and sinusitis during postmarketing experience.


Immunologic side effects have included immune reconstitution syndrome. Autoimmune disorders (e.g., Graves' disease, polymyositis, and Guillain-Barre syndrome) have been reported in the setting of immune reconstitution.


A case of macular edema in a patient with a history of anterior uveitis secondary to syphilis has been reported.

Ocular side effects have included amblyopia, macular edema, and photophobia during postmarketing experience.


Genitourinary side effects have included gynecomastia, urinary frequency, and urinary hesitancy during postmarketing experience.

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