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Mebendazole Side Effects

Medically reviewed by Drugs.com. Last updated on May 14, 2020.

For the Consumer

Applies to mebendazole: oral tablet chewable

Side effects requiring immediate medical attention

Along with its needed effects, mebendazole 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 mebendazole:

Rare

  • Black, tarry stools
  • chills
  • convulsions
  • cough or hoarseness
  • dark urine
  • fever with or without chills
  • general feeling of tiredness or weakness
  • hives or welts, itching, or skin rash
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • light-colored stools
  • lower back or side pain
  • nausea and vomiting
  • painful or difficult urination
  • pale skin
  • redness of the skin
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • upper right abdominal or stomach pain
  • yellow eyes and skin

Incidence not known

  • Blistering, peeling, or loosening of the skin
  • diarrhea
  • difficulty with swallowing
  • dizziness
  • fast heartbeat
  • joint or muscle pain
  • red skin lesions, often with a purple center
  • red, irritated eyes
  • tightness in the chest

Side effects not requiring immediate medical attention

Some side effects of mebendazole 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:

Rare

  • Abdominal or stomach pain or upset

Incidence not known

  • Bloated
  • excess air or gas in the stomach or intestines
  • full feeling
  • hair loss or thinning of the hair
  • loss of appetite
  • passing gas
  • weight loss

For Healthcare Professionals

Applies to mebendazole: compounding powder, oral tablet chewable

General

At the recommended dose, this drug was generally well tolerated; however, patients with high parasitic burdens reported diarrhea and abdominal pain.[Ref]

Gastrointestinal

Common (1% to 10%): Abdominal pain

Uncommon (0.1% to 1%): Abdominal discomfort, diarrhea, flatulence

Frequency not reported: Nausea, vomiting[Ref]

Dermatologic

Rare (0.01% to 0.1%): Rash

Frequency not reported: Pruritus

Postmarketing reports: Toxic epidermal necrolysis, Stevens-Johnson syndrome, exanthema, alopecia, angioedema, urticaria[Ref]

Metabolic

Frequency not reported: Anorexia[Ref]

Hepatic

Frequency not reported: Transient changes in liver function tests, granulomatous hepatitis

Postmarketing reports: Hepatitis, abnormal liver function tests[Ref]

Hematologic

Frequency not reported: Profound leukopenia, anemia, thrombocytopenia, pancytopenia

Postmarketing reports: Agranulocytosis, neutropenia[Ref]

Nervous system

Frequency not reported: Weakness, drowsiness

Postmarketing reports: Convulsions/seizures, dizziness[Ref]

Renal

Postmarketing reports: Glomerulonephritis[Ref]

Other

Frequency not reported: Chills, drug fever, flushing[Ref]

Hypersensitivity

Postmarketing reports: Hypersensitivity (including anaphylactic reaction, anaphylactoid reaction)[Ref]

References

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

2. Barrett-Connor E "Drugs for the treatment of parasitic infection." Med Clin North Am 66 (1982): 245-55

3. Bekhti A, Pirotte J "Hepatotoxicity of mebendazole: relationship with serum concentrations of the drug." Gastroenterol Clin Biol 11 (1987): 701-3

4. "Product Information. Vermox (mebendazole)." Janssen Pharmaceutica, Titusville, NJ.

5. Kammerer WS, Schantz PM "Long term follow-up of human hydatid disease (echinococcus granulosus) treated with a high-dose mebendazole regimen." Am J Trop Med Hyg 33 (1984): 132-7

6. Miskovitz PF, Javitt NB "Leukopenia associated with mebendazole therapy of hydatid disease." Am J Trop Med Hyg 29 (1980): 1356-8

7. Witassek F, Bircher "Chemotherapy of larval echinococcosis with mebendazole: microsomal liver function and cholestasis as determinants of plasma drug level." Eur J Clin Pharmacol 25 (1983): 85-90

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

9. Braithwaite PA, Thomas RJ, Thompson RC "Hydatid disease, the alveolar variety in australia: a case report with comment on the toxicity of mebendazole." Aust N Z J Surg 55 (1985): 519-23

10. Colle I, Naegels S, Hoorens A, Hautekeete M "Granulomatous hepatitis due to mebendazole." J Clin Gastroenterol 28 (1999): 44-5

11. Levin MH, Weinstein RA, Axelrod JL, Schantz PM "Severe, reversible neutropenia during high-dose mebendazole therapy for echinococcosis." JAMA 249 (1983): 2929-31

12. Fernandez-Banares F, Gonzalez-Huix F, Xiol X, et al "Marrow aplasia during high dose mebendazole treatment." Am J Trop Med Hyg 35 (1986): 350-1

13. Murray-Lyon IM, Reynolds KW "Complication of mebendazole treatment for hydatid disease." Br Med J 2 (1979): 1111-2

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.