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Drugs and diseases reference index

Drugs reference index «Rifaximin»



Pronunciation: (riff-AX-ih-min)Class: Anti-infective agent

Trade Names:Xifaxan- Tablets 200 mg


Inhibits bacterial RNA synthesis.



Systemic absorption is low. Mean C max 4.3 ng/mL; median T max is 1.25 h; mean AUC 19.5 ng•h/mL.


Induces CYP3A4 in in vitro studies; however, because of low systemic absorption, clinically important interactions are unlikely.


The t ½ is 5.9 h. Excreted primarily in feces (97% of administered dose) and 0.32% unchanged in the urine.

Indications and Usage

Treatment of travelers' diarrhea by noninvasive strains of Escherichia coli .


Hypersensitivity to any rifamycins or any component of product.

Dosage and Administration

Adults and children 12 yr of age and older

PO 200 mg 3 times daily for 3 days.


Store tablets at controlled room temperature (59° to 86°F).

Drug Interactions

None well documented.

Laboratory Test Interactions

None well documented.

Adverse Reactions


Headache (10%); abnormal dreams, dizziness, migraine, syncope, loss of taste, insomnia fatigue (less than 2%).


Sunburn, clamminess, rash, increased sweating (less than 2%).


Ear pain, motion sickness, tinnitus, nasal passage irritation, nasopharyngitis, pharyngitis, pharyngolaryngeal pain, rhinitis, rhinorrhea (less than 2%).


Constipation (4%); vomiting (2%); abdominal distension, diarrhea, dry throat, fecal abnormality, gingival disorder, inguinal hernia, dry lips, stomach discomfort, dysentery, blood in stool, anorexia (less than 2%).


Blood in urine, choluria, dysuria, hematuria, polyuria, proteinuria, urinary frequency (less than 2%).


Lymphocytosis, monocytosis, neutropenia (less than 2%).


Allergic dermatitis, rash, angioneurotic edema, urticaria, pruritus (postmarketing).

Lab Tests

Increased aspartate aminotransferase (less than 2%).


Weight loss, dehydration (less than 2%).


Arthralgia, muscle spasms, myalgia, neck pain (less than 2%).


Respiratory tract infection, upper respiratory tract infection, dyspnea (less than 2%).


Chest pain, malaise, pain, weakness, hot flashes (less than 2%).



Category C .




Safety and efficacy not established in children less than 12 yr of age.


Use may result in bacterial or fungal overgrowth.

Clostridia overgrowth

Treatment with rifaximin may permit overgrowth of Clostridia .


Not found to be effective in treating travelers' diarrhea caused by pathogens other than E. coli .

Pseudomembranous colitis

Should be considered in patients in whom diarrhea develops subsequent to treatment.

Patient Information

  • Advise patient to read patient information leaflet before starting therapy.
  • Review the following decision-making skills that reduce the chances of getting travelers' diarrhea: eat only thoroughly cooked foods; drink bottled water, boiled water, or beverages made with boiled water; drink carbonated beverages in bottles or cans; avoid tap water, fountain drinks, and beverages containing ice.
  • Review dosing schedule and prescribed length of therapy with patient.
  • Caution patient that medication is to be taken only if they get diarrhea while traveling, but not to take in an effort to prevent diarrhea.
  • Instruct patient not to take rifaximin if they have diarrhea and a fever, or have blood in their stools. Instruct patient to seek medical care if either of these occurs.
  • Advise patient to take prescribed dose without regard to meals but to take with food if stomach upset occurs.
  • Instruct patient to complete entire course of therapy, even if symptoms of travelers' diarrhea have disappeared.
  • Advise patient that diarrhea should resolve within 24 to 48 h after starting therapy. Instruct patient to notify health care provider if diarrhea symptoms worsen or persist more than 48 h.
  • Caution patient that although this medication is an antibiotic, it does not get into the bloodstream and will not work to treat other infections such as chest, sinus, or lung infections caused by bacteria.
  • Advise patient to report the following signs of superinfection to health care provider: black “furry” tongue, white patches in mouth, foul-smelling stools, vaginal itching or discharge.
  • Warn patient that diarrhea containing blood or pus may be a sign of a serious disorder and to seek medical care if noted and not treat at home.
  • Advise patient that drug may cause dizziness and to use caution while driving or performing other tasks requiring mental alertness until tolerance is determined.

Copyright © 2009 Wolters Kluwer Health.

  • Rifaximin MedFacts Consumer Leaflet (Wolters Kluwer)
  • Rifaximin Detailed Consumer Information (PDR)
  • rifaximin Advanced Consumer (Micromedex) - Includes Dosage Information
  • Xifaxan Prescribing Information (FDA)
  • Xifaxan Consumer Overview

See Also...

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