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Zidovudine Side Effects

Medically reviewed by Drugs.com. Last updated on Feb 20, 2025.

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

Other dosage forms:

Important warnings This medicine can cause some serious health issues

Oral route (capsule; tablet; syrup)

Zidovudine has been associated with hematologic toxicity, including neutropenia and severe anemia, particularly in patients with advanced HIV disease.

Prolonged use of zidovudine has been associated with symptomatic myopathy. Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported.

Suspend treatment if clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity occur.

Serious side effects of zidovudine

Along with its needed effects, zidovudine 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 zidovudine:

More common side effects

  • black, tarry stools
  • chills
  • cough
  • feeling of fullness
  • fever
  • lower back or side pain
  • painful or difficult urination
  • pale skin
  • right upper abdominal pain and fullness
  • sore throat
  • stomach pain
  • swelling or inflammation of the mouth
  • swollen lymph nodes
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Rare side effects

  • confusion
  • diarrhea
  • fast, shallow breathing
  • general feeling of discomfort
  • loss of appetite
  • mood or mental changes
  • muscle pain, tenderness, weakness, or cramping
  • nausea
  • seizures
  • sleepiness
  • stomach discomfort

Incidence not known

  • back or leg pain
  • bleeding gums
  • blistering, peeling, or loosening of the skin
  • bloating
  • blood in the urine
  • blurred vision or other change in vision
  • bone pain
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • clay-colored stools
  • constipation
  • dark urine
  • decreased appetite
  • decreased urine output
  • difficult or labored breathing
  • difficulty in moving
  • difficulty in swallowing
  • dilated neck veins
  • dizziness
  • extreme tiredness or weakness
  • fainting
  • fast, irregular, or pounding heartbeat
  • general body swelling
  • general tiredness and weakness
  • headache
  • high fever
  • hives, skin rash
  • hoarseness
  • increased need to urinate
  • indigestion
  • irregular breathing
  • irritation or soreness of the mouth
  • joint or muscle pain
  • lack of coordination
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or genitals
  • light-colored stools
  • muscle pain, cramp, spasm, or stiffness
  • nosebleeds
  • pains in the stomach, side, or abdomen, possibly radiating to the back
  • passing urine more often
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • redness, soreness, or itching skin
  • runny nose
  • shakiness in the legs, arms, hands, or feet
  • shivering
  • sores, welts, or blisters
  • stabbing pain
  • sweating
  • swollen joints
  • swollen or painful glands
  • tightness in the chest
  • trouble sleeping
  • unexplained bleeding or bruising
  • unpleasant breath odor
  • vomiting
  • vomiting of blood
  • weight gain
  • yellow eyes or skin

Other side effects of zidovudine

Some side effects of zidovudine 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 side effects

  • difficulty having a bowel movement
  • headache (severe)
  • lack or loss of strength
  • muscle soreness
  • weight loss

Less common side effects

  • bluish-brown colored bands on nails
  • changes in skin color

Incidence not known

  • belching
  • heartburn
  • stomach cramps

Managing side effects (general information)

For healthcare professionals

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

General adverse events

The most common side effects reported during adult clinical trials were headache, malaise, nausea, anorexia, and vomiting; side effects reported most often with IV administration were anemia and neutropenia. The most common side effects reported during pediatric clinical trials were fever and cough. In the prevention of maternal-fetal transmission clinical trial, the most common side effects reported in neonates were anemia and neutropenia.[Ref]

Hematologic

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 this drug was part of the HIV-1 regimen.[Ref]

Nervous system

Other

Antiretroviral therapy:

In 1 case of drug-associated fever, no source of infection was found after an extensive evaluation, but an anti-zidovudine immunoglobulin was isolated, indicating a possible hypersensitivity reaction.

This drug has been associated with lower levels of vitamins B2 and C, folate, and zinc despite adequate dietary intake.[Ref]

Gastrointestinal

Metabolic

Antiretroviral therapy:

Lactic acidosis and severe hepatomegaly with steatosis (including fatal cases) have been reported with the use of nucleoside analogs.[Ref]

Hepatic

A patient with preexisting hepatitis B developed acute hepatic failure 2 weeks after starting this drug.

Lactic acidosis and severe hepatomegaly with steatosis (including fatal cases) have been reported with the use of nucleoside analogs.

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.[Ref]

Musculoskeletal

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.

In 1 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. Dose 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 this drug.[Ref]

Psychiatric

Dermatologic

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

Cardiovascular

Hypersensitivity

Respiratory

Immunologic

Ocular

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

Genitourinary

Endocrine

Local

Local reaction, pain, and slight irritation were reported infrequently during IV administration.

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Further information

Zidovudine side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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