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Bezlotoxumab Side Effects

Medically reviewed by Last updated on Oct 15, 2022.

Applies to bezlotoxumab: intravenous solution.

Serious side effects of Bezlotoxumab

Along with its needed effects, bezlotoxumab 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 or nurse immediately if any of the following side effects occur while taking bezlotoxumab:

More common

  • Back pain
  • chest pain
  • chest tightness
  • chills
  • decreased urine output
  • dilated neck veins
  • extreme fatigue
  • fever
  • flushing
  • headache
  • irregular breathing
  • irregular heartbeat
  • nausea and vomiting
  • swelling of face, fingers, feet, or lower legs
  • tightness in the chest
  • troubled breathing
  • weakness
  • weight gain

Other side effects of Bezlotoxumab

Some side effects of bezlotoxumab 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:

Incidence not known

  • Bleeding, blistering, burning, coldness, discoloration of the skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration, or warmth at the injection site

For Healthcare Professionals

Applies to bezlotoxumab: intravenous solution.


Common (1% to 10%): Dyspnea[Ref]


Common (1% to 10%): Heart failure, hypertension[Ref]


Common (1% to 10%): Nausea[Ref]

Nervous system

Common (1% to 10%): Headache, fatigue, dizziness[Ref]


Common (1% to 10%): Pyrexia[Ref]


1. "Product Information. Zinplava (bezlotoxumab)." Merck & Company Inc (2016):

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.