Rifaximin

Indications
Rifaximin is indicated for the treatment of patients with traveler's diarrhea caused by noninvasive strains of Escherichia coli at lower dose. Rifaximin is also indicated for reduction in risk of overt hepatic encephalopathy (HE) at higher dose.

Therapeutic Class
4-Quinolone preparations

Pharmacology
Rifaximin is a non-systemic, rifamycin antibiotic which is structural analog of rifampin. Rifaximin acts by binding to the beta-subunit of bacterial DNA-dependent RNA polymerase resulting in inhibition of bacterial RNA synthesis.

Dosage & Administration
For traveler's diarrhea (>12 years of age): The recommended dose of Rifaximin is 200 mg taken orally three times a day for 3 days.
For hepatic encephalopathy (>18 years of age): The recommended dose of Rifaximin is 550 mg taken orally two times a day.
Rifaximin can be administered orally, with or without food.

Interaction
Rifaximin does not inhibit cytochrome P-450 isoenzymes at concentrations ranging from 2 to 200 ng/ml.

Contraindications
Rifaximin is contraindicated in patients with a hypersensitivity to Rifaximin or any of the components or any of the rifamycin antimicrobial agents. Hypersensitivity reactions include exfoliative dermatitis, angioneurotic edema and anaphylaxis.

Side Effects
Most common side effects in traveler's diarrhea: Flatulence, headache, abdominal pain, rectal tenesmus, defecation urgency and nausea. Most common side effects in hepatic encephalopathy: Peripheral edema, nausea, dizziness, fatigue, ascites, flatulence and headache.

Pregnancy & Lactation
Pregnancy Category C. There are no adequate and well controlled studies in pregnant women. Based on animal data, Rifaximin may cause fetal harm. It should be used during pregnancy only if the potential benefit outweighs the probable risk to the fetus. Discontinue nursing or drug, taking into account the importance of the drug to the mother.

Precautions & Warnings
Rifaximin is not effective in diarrhea complicated by fever or blood in the stool or diarrhea due to pathogens other than Escherichia coli. If diarrhea symptoms get worse or persist for more than 24-48 hours, discontinue Rifaximin and consider alternative antibiotics. Rifaximin should be used with caution in patients with severe hepatic impairment.

Storage Conditions
Keep in a dry place away from light and heat. Keep out of the reach of children.