Indications: Traveler's Diarrhea. Hepatic Encephalopathy. Irritable Bowel Syndrome (Off-label) Cautions: Not effective in diarrhea complicated by fever, hematochezia, or diarrhea due to pathogens other than Escherichia coli Not effective against traveler's diarrhea due to Campylobacter jejuni Clostridium difficile-associated diarrhea has been reported Efficacy against traveler's diarrhea due to Shigella spp and Salmonella spp not proven Discontinue if symptoms worsen or persist >24-48 hr Possibility of pseudomembranous colitis Monitor patients with severe hepatic impairment for increased systemic exposure Co administration with P-gp inhibitors substantially increases systemic exposure to rifaximin; co administration of cyclosporine with rifaximin resulted in 83-fold and 124-fold increases in rifaximin mean Cmax and AUC in healthy subjects.

Hepatic impairment: manufacturer advises caution when used for hepatic encephalopathy in patients with severe hepatic impairment.

Pregnancy: manufacturer advises avoid—toxicity in animal studies.

Breast-feeding: unlikely to be present in milk in significant amounts, but manufacturer advises avoid.

Contra-indications: Hypersensitivity to rifamycin antibiotics.

Side Effects: nausea, vomiting, abdominal pain, flatulence, diarrhoea, dyspnea, headache, depression, dizziness, muscle spasm, rash, pruritus; less commonly anorexia, taste disturbances, dry mouth, peripheral oedema, sleep disturbances, anxiety, memory impairment, convulsions, hypoaesthesia, paraesthesia, antibiotic- associated colitis, influenza-like symptoms, dysuria, polyuria, glycosuria, polymenorrhoea, blood disorders, hyperkalaemia; rarely blood pressure changes, constipation; also reported syncope.

Dose: For Adult: Traveler's Diarrhea: 200 mg PO q8hr for 3 days Hepatic Encephalopathy Maintenance of remission: Table Of Content 550 mg PO q12hr Irritable Bowel Syndrome (Offlabel) 550 mg PO q8hr for 14 days Dosing Considerations: 2 trials (n >600 in each) in patients with IBS without constipation showed rifaximin to be more effective than placebo in providing adequate symptom relief Can take with or without food For pediatric: <12 years: Safety and efficacy not established.

≥12 years: 200 mg PO q8hr for 3 days, with or without food.