Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 7/2/2021
Dificid Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

What Is Dificid?

Dificid (fidaxomicin) is a macrolide antibacterial drug used to reduce the development of drug-resistant bacteria and to treat Clostridium difficile-associated diarrhea (CDAD) in adults over the age of 18. Dificid should only be used to treat infections that are proven or strongly suspected to be caused by Clostridium difficile (also called C. difficile). Dificid is not an effective treatment for systemic infections.

What Are Side Effects of Dificid?

Common side effects of Dificid are:

Dosage for Dificid

Dificid (fidaxomicin) is available only as 200 mg strength tablets. The recommended dose is one 200 mg Dificid tablet orally twice daily for 10 days with or without food. Serious side effects are GI bleeding and intestinal obstruction.

What Drugs, Substances, or Supplements Interact with Dificid?

Dificid is known to react with Cyclosporine. There are no adequate and well-controlled studies in pregnant women or in children under age 18.

Dificid During Pregnancy or Breastfeeding

This drug should be used during pregnancy only if clearly needed. It is not known whether fidaxomicin is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Dificid is administered to a nursing woman.

Additional Information

Our Dificid (fidaxomicin) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Dificid Consumer Information

Stop taking fidaxomicin and get emergency medical help if you have signs of an allergic reaction: hives, rash, itching; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • inflammation in your colon--stomach pain and bloating, painful or bloody stools, fast heartbeats, cool or clammy skin, feeling like you might pass out;
  • low blood cell counts--fever, chills, tiredness, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath; or
  • signs of stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds.

Common side effects may include:

  • nausea, vomiting, stomach pain;
  • diarrhea, constipation;
  • stomach bleeding;
  • fever;
  • low blood cell counts;
  • abnormal liver function tests; or
  • rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Read the entire detailed patient monograph for Dificid (Fidaxomicin Tablets for Oral Administration)


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Dificid Professional Information


Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The safety of DIFICID 200 mg tablets taken twice a day for 10 days was evaluated in 564 patients with CDAD in two active-comparator controlled trials with 86.7% of patients receiving a full course of treatment.

Thirty-three patients receiving DIFICID (5.9%) withdrew from trials as a result of adverse reactions (AR). The types of AR resulting in withdrawal from the study varied considerably. Vomiting was the primary adverse reaction leading to discontinuation of dosing; this occurred at an incidence of 0.5% in both the fidaxomicin and vancomycin patients in Phase 3 studies.

Table 1: Selected Adverse Reactions with an Incidence of ≥2% Reported in DIFICID Patients in Controlled

System Organ Class
Preferred Term
(N=564) n (%)
(N=583) n (%)
Blood and Lymphatic System Disorders
Anemia 14 (2%) 12 (2%)
Neutropenia 14 (2%) 6 (1%)
Gastrointestinal Disorders
Nausea 62 (11%) 66 (11%)
Vomiting 41 (7%) 37 (6%)
Abdominal Pain 33 (6%) 23 (4%)
Gastrointestinal Hemorrhage 20 (4%) 12 (2%)

The following adverse reactions were reported in <2% of patients taking DIFICID tablets in controlled trials:

Gastrointestinal Disorders: abdominal distension, abdominal tenderness, dyspepsia, dysphagia, flatulence, intestinal obstruction, megacolon

Investigations: increased blood alkaline phosphatase, decreased blood bicarbonate, increased hepatic enzymes, decreased platelet count

Metabolism and Nutrition Disorders: hyperglycemia, metabolic acidosis

Skin and Subcutaneous Tissue Disorders: drug eruption, pruritus, rash

Post Marketing Experience

Adverse reactions reported in the post marketing setting arise from a population of unknown size and are voluntary in nature. As such, reliability in estimating their frequency or in establishing a causal relationship to drug exposure is not always possible.

Hypersensitivity reactions (dyspnea, angioedema, rash, and pruritus) have been reported.

Read the entire FDA prescribing information for Dificid (Fidaxomicin Tablets for Oral Administration)

© Dificid Patient Information is supplied by Cerner Multum, Inc. and Dificid Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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