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Fidaxomicin Side Effects

In Summary

More frequently reported side effects include: vomiting. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to fidaxomicin: oral tablet

Along with its needed effects, fidaxomicin 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 fidaxomicin:

Less Common

  • Abdominal or stomach pain
  • bloating
  • bloody or black, tarry stools
  • chills
  • confusion
  • constipation
  • cough
  • drowsiness
  • fever
  • loss of appetite
  • lower back or side pain
  • muscle tremors
  • nausea
  • painful or difficult urination
  • pale skin
  • rapid, deep breathing
  • restlessness
  • severe constipation
  • shortness of breath
  • sore throat
  • stomach cramps
  • troubled breathing with exertion
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting
  • vomiting of blood or material that looks like coffee grounds

Some side effects of fidaxomicin 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:

Less Common

  • Abdominal or stomach distension or tenderness
  • acid or sour stomach
  • belching
  • blurred vision
  • difficulty with swallowing
  • dry mouth
  • excess air or gas in the stomach or intestines
  • flushed, dry skin
  • fruit-like breath odor
  • full feeling
  • heartburn
  • increased hunger
  • increased thirst
  • increased urination
  • indigestion
  • itching skin
  • passing gas
  • rash
  • stomach discomfort or upset
  • sweating
  • troubled breathing
  • unexplained weight loss

For Healthcare Professionals

Applies to fidaxomicin: oral tablet


Very common (10% or more): Nausea (11%)

Common (1% to 10%): Vomiting (7%), abdominal pain (6%), gastrointestinal hemorrhage (4%), abdominal distension (less than 2%), abdominal tenderness (less than 2%), dyspepsia (less than 2%), dysphagia (less than 2%), flatulence (less than 2%), intestinal obstruction (less than 2%), megacolon (less than 2%)[Ref]


Common (1% to 10%): Anemia (2%), neutropenia (2%), decreased platelet count (less than 2%)[Ref]


Common (1% to 10%): Drug eruption (less than 2%), pruritus (less than 2%), rash (less than 2%)[Ref]


Common (1% to 10%): Increased hepatic enzymes (less than 2%)[Ref]


Common (1% to 10%): Hyperglycemia (less than 2%), metabolic acidosis (less than 2%), increased blood alkaline phosphatase (less than 2%), decreased blood bicarbonate (less than 2%)[Ref]


Postmarketing reports: Hypersensitivity reactions (dyspnea, angioedema, rash, pruritus)


1. "Product Information. Dificid (fidaxomicin)." Optimer Pharmaceuticals, San Diego, CA.

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.