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Fidaxomicin Side Effects

Medically reviewed by Last updated on Jul 9, 2022.


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

For the Consumer

Applies to fidaxomicin: oral powder for suspension, oral tablet

Side effects requiring immediate medical attention

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
  • 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

Incidence not known

  • Difficult or labored breathing
  • itching skin or rash
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • tightness in the chest

Side effects not requiring immediate medical attention

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
  • passing gas
  • stomach discomfort or upset
  • sweating
  • troubled breathing
  • unexplained weight loss

For Healthcare Professionals

Applies to fidaxomicin: oral granule for reconstitution, oral tablet


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

Common (1% to 10%): Vomiting, abdominal pain, diarrhea, constipation, gastrointestinal hemorrhage, upper abdominal pain

Uncommon (0.1% to 1%): Abdominal distension, flatulence, dry mouth

Frequency not reported: Abdominal tenderness, dyspepsia, dysphagia, intestinal obstruction, megacolon, lower abdominal pain[Ref]


Common (1% to 10%): Hypokalemia, hyperkalemia, hypomagnesemia

Uncommon (0.1% to 1%): Anorexia, decreased appetite

Frequency not reported: Hyperglycemia, metabolic acidosis[Ref]

Nervous system

Common (1% to 10%): Headache, dizziness

Uncommon (0.1% to 1%): Dysgeusia[Ref]


Common (1% to 10%): Pyrexia, peripheral edema, fatigue

Uncommon (0.1% to 1%): Chills

Frequency not reported: Increased blood alkaline phosphatase, decreased blood bicarbonate[Ref]


Common (1% to 10%): Urinary tract infection[Ref]


Common (1% to 10%): Anemia, neutropenia

Frequency not reported: Decreased platelet count[Ref]


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


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


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


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


Common (1% to 10%): Pruritus

Uncommon (0.1% to 1%): Rash

Frequency not reported: Drug eruption, urticaria, follicular rash, maculopapular rash, exfoliative rash[Ref]


Common (1% to 10%): Back pain[Ref]


Uncommon (0.1% to 1%): Increased ALT

Frequency not reported: Increased hepatic enzymes, increased AST[Ref]


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

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

3. "Product Information. Dificid (fidaxomicin)." Optimer Pharmaceuticals (2011):

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.