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Rifaximin Side Effects

Medically reviewed by Last updated on May 12, 2021.

In Summary

Commonly reported side effects of rifaximin include: flatulence. Other side effects include: abdominal pain, bowel urgency, headache, nausea, and rectal tenesmus. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to rifaximin: oral tablet

Side effects requiring immediate medical attention

Along with its needed effects, rifaximin 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 rifaximin:

More common

  • Black, tarry stools
  • dizziness or lightheadedness
  • muscle spasm
  • rapid breathing
  • shortness of breath
  • trouble sleeping

Less common

  • Blood in the urine
  • bloody nose
  • chest pain
  • continuing ringing or buzzing or other unexplained noise in the ears
  • fainting
  • feeling of constant movement of self or surroundings
  • increased heart rate
  • sensation of spinning
  • sunken eyes
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Incidence not known

  • Cracks in the skin
  • hives or welts, itching skin, or rash
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • loss of heat from the body
  • red, swollen skin
  • redness of the skin
  • scaly skin

Side effects not requiring immediate medical attention

Some side effects of rifaximin 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:

More common

  • Bloated
  • difficulty with moving
  • excess air or gas in the stomach or intestines
  • fever
  • frequent urge to defecate
  • full feeling
  • headache
  • lower back or side pain
  • muscle pain or stiffness
  • pain in the joints
  • passing gas
  • stomach pain
  • straining while passing stool
  • swelling of the hands, ankles, feet, or lower legs

Less common

  • Abnormal dreams
  • blurred vision
  • chills
  • confusion
  • cough
  • decreased urination
  • difficulty having a bowel movement (stool)
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • dry lips
  • dry mouth
  • ear pain
  • feeling of warmth
  • hearing loss
  • lightheadedness
  • loss of appetite
  • loss of taste
  • nausea
  • painful or difficult urination
  • pale skin
  • redness of the face, neck, arms, and occasionally, upper chest
  • sore throat
  • sweating
  • swollen glands
  • thirst
  • vomiting
  • wrinkled skin

For Healthcare Professionals

Applies to rifaximin: oral tablet


When used for the treatment of travelers' diarrhea, the most common side effect was headache. This drug was discontinued due to side effects in 0.4% of patients; such side effects were taste loss, dysentery, decreased weight, anorexia, nausea, and nasal passage irritation.

When used for reduction in risk of overt hepatic encephalopathy recurrence, the most common side effects were peripheral edema, nausea, dizziness, fatigue, and ascites.

When used for the treatment of irritable bowel syndrome with diarrhea, the most common side effects were nausea and increased ALT.[Ref]


Very common (10% or more): Nausea (up to 14.3%), ascites (11.4%), flatulence (up to 11%)

Common (1% to 10%): Abdominal pain, abdominal distension, rectal tenesmus, upper abdominal pain, defecation urgency, constipation, stomach discomfort, vomiting, lower abdominal pain, abdominal tenderness, dry mouth, esophageal variceal bleed, diarrhea, bloating and distension, nausea and vomiting symptoms

Uncommon (0.1% to 1%): Dry lips, dyspepsia, gastrointestinal motility disorder, hard feces, hematochezia, mucous stools, taste disorders

Frequency not reported: Blood in stool, dysentery, fecal abnormality, gingival disorder, inguinal hernia, straining, bad taste in mouth, Clostridium colitis

Postmarketing reports: Clostridioides difficile-associated colitis[Ref]


Very common (10% or more): Peripheral edema (15%), fatigue (up to 12.1%)

Common (1% to 10%): Pyrexia, chest pain, pain, generalized edema, influenza-like illness, contusion, fall, procedural pain

Uncommon (0.1% to 1%): Ear pain, candidiasis, hot flush, edema, herpes simplex, asthenic conditions, pain and discomfort, chills

Rare (less than 0.1%): Asthenia

Frequency not reported: Motion sickness, malaise, hot flashes

Postmarketing reports: Clostridial infections (C difficile)[Ref]

Nervous system

Very common (10% or more): Dizziness (up to 13%), headache (10%)

Common (1% to 10%): Vertigo, amnesia, disturbance in attention, hypoesthesia, memory impairment, tremor

Uncommon (0.1% to 1%): Balance disorders, convulsion, attention disorders, migraine, paresthesia, sinus headache, somnolence

Frequency not reported: Syncope, tinnitus, loss of taste

Postmarketing reports: Presyncope, syncope[Ref]


Hypersensitivity reactions have occurred as early as within 15 minutes of drug administration.[Ref]

Frequency not reported: Anaphylactic reactions

Postmarketing reports: Hypersensitivity reactions (including exfoliative dermatitis, rash, angioneurotic edema [swelling of face and tongue and difficulty swallowing], urticaria, pruritus, flushing, anaphylaxis), anaphylactic responses, angioedemas, hypersensitivity[Ref]


Common (1% to 10%): Pruritus, rash, cellulitis

Uncommon (0.1% to 1%): Eruptions and exanthemas, sunburn, hyperhidrosis/increased sweating, cold sweat

Frequency not reported: Clamminess

Postmarketing reports: Angioedema, dermatitis, exfoliative dermatitis, eczema, erythemas, pruritus, purpura, urticarias[Ref]


Rhabdomyolysis has been reported in patients with cirrhosis (with and without concurrent statin use).[Ref]

Common (1% to 10%): Muscle spasms, arthralgia, back pain, myalgia, pain in extremity

Uncommon (0.1% to 1%): Neck pain, muscular weakness

Frequency not reported: Increased blood creatine phosphokinase

Postmarketing reports: Rhabdomyolysis[Ref]


Common (1% to 10%): Anemia

Uncommon (0.1% to 1%): Lymphocytosis, monocytosis, neutropenia

Postmarketing reports: Thrombocytopenia, INR abnormalities[Ref]


Common (1% to 10%): Cough, nasopharyngitis, dyspnea, upper respiratory tract infection, rhinitis, pneumonia, epistaxis

Uncommon (0.1% to 1%): Pleural effusion, pharyngitis, oropharyngeal pain, rhinorrhea, dry throat, nasal congestion

Rare (less than 0.1%): Chronic obstructive pulmonary disease

Frequency not reported: Respiratory tract infection, nasal passage irritation, pharyngolaryngeal pain[Ref]


Common (1% to 10%): Depression, insomnia, confusional state

Uncommon (0.1% to 1%): Anxiety, hypersomnia, abnormal dreams, depressed mood, nervousness[Ref]


Common (1% to 10%): Increased weight, anorexia, dehydration, hyperglycemia, hyperkalemia, hypoglycemia, hyponatremia

Uncommon (0.1% to 1%): Decreased appetite

Frequency not reported: Decreased weight[Ref]


Common (1% to 10%): Hypotension

Uncommon (0.1% to 1%): Palpitations, increased blood pressure

Rare (less than 0.1%): Hypertension[Ref]


Uncommon (0.1% to 1%): Urinary tract infection, dysuria, polyuria, proteinuria, pollakiuria, blood in urine present, glycosuria, polymenorrhea

Frequency not reported: Choluria, hematuria, urinary frequency[Ref]


Common (1% to 10%): Increased ALT

Uncommon (0.1% to 1%): Increased AST

Postmarketing reports: Liver function test abnormalities[Ref]


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


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

2. "Product Information. Xifaxan (rifaximin)." Salix Pharmaceuticals, Raleigh, NC.

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

4. Garey KW, Salazar M, Shah D, Rodrigue R, Dupont HL "Rifamycin antibiotics for treatment of Clostridium difficile-associated diarrhea." Ann Pharmacother 42 (2008): 827-35

5. "Rifaximin (Xifaxan 550) for hepatic encephalopathy." Med Lett Drugs Ther 52 (2010): 87

6. Pimentel M, Park S, Mirocha J, Kane SV, Kong Y "The effect of a nonabsorbed oral antibiotic (rifaximin) on the symptoms of the irritable bowel syndrome: a randomized trial." Ann Intern Med 145 (2006): 557-63

7. Juillerat P, Pittet V, Felley C, et al. "Drug safety in Crohn's disease therapy." Digestion 76 (2007): 161-8

8. Trapnell CB, Connolly M, Pentikis H, Forbes B, Bettenhausen DK "Absence of effect of oral rifaximin on the pharmacokinetics of ethinyl estradiol/norgestimate in healthy females." Ann Pharmacother 41 (2007): 222-8

9. Hynicka LM, Silva KN "Probable rifaximin-induced neutropenia." Am J Health Syst Pharm 69 (2012): 583-6

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.