Dosing & Uses
Dosage Forms & Strengths
tablet
- 200mg
- 550mg
Traveler's Diarrhea
Indicated for travelers' diarrhea caused by noninvasive strains of Escherichia coli (E coli)
200 mg PO q8hr for 3 days
Hepatic Encephalopathy
Maintenance of remission
550 mg PO q12hr
Irritable Bowel Syndrome
Indicated for irritable bowel syndrome with diarrhea (IBS-D) in adult men and women
550 mg PO q8hr for 14 days; recurrence of symptoms can be retreated with a 14 day treatment course, up to 2 times
Available in unit-dose package containing 42 tablets (ie, 2 week supply) for this indication
Dosing Considerations
Limitations of use: Not indicated or shown effective in patients with traveler's diarrhea complicated by fever or bloody stool or due to pathogens other than non-invasive strains of E coli
To reduce the development of drug-resistant bacteria and maintain effectiveness of antibiotics, rifamycin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria
Dosage Forms & Strengths
tablet
- 200mg
- 550mg
Traveler's Diarrhea
Indicated for travelers' diarrhea caused by noninvasive strains of Escherichia coli (E coli)
<12 years: Safety and efficacy not established
≥12 years: 200 mg PO q8hr for 3 days, with or without food
Dosing Considerations
Limitations of use: Not indicated or shown effective in patients with traveler's diarrhea complicated by fever or bloody stool or due to pathogens other than non-invasive strains of E coli
To reduce the development of drug-resistant bacteria and maintain effectiveness of antibiotics, rifamycin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (0)
Serious - Use Alternative (6)
- BCG intravesical live
rifaximin decreases effects of BCG intravesical live by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Suspend BCG intravesical live therapy during antibiotic therapy.
- cholera vaccine
rifaximin, cholera vaccine. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Avoid coadministration of cholera vaccine with systemic antibiotics since these agents may be active against the vaccine strain. Do not administer cholera vaccine to patients who have received oral or parenteral antibiotics within 14 days prior to vaccination.
- lasmiditan
lasmiditan increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug.
- microbiota oral
rifaximin decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores. Antibacterial agents may decrease efficacy if coadministered. Complete antibiotic regimens 2-4 days before initiating microbiota oral. .
- sotorasib
sotorasib will decrease the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If use is unavoidable, refer to the prescribing information of the P-gp substrate for dosage modifications.
- tepotinib
tepotinib will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Avoid or Use Alternate Drug. If concomitant use unavoidable, reduce the P-gp substrate dosage if recommended in its approved product labeling.
Monitor Closely (62)
- abiraterone
abiraterone increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- afatinib
afatinib increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- amiodarone
amiodarone increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- azithromycin
azithromycin increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- berotralstat
berotralstat will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.
- carvedilol
carvedilol increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- clarithromycin
clarithromycin increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- crizotinib
crizotinib increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- cyclosporine
cyclosporine increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Coadministration of cyclosporine with rifaximin resulted in 83-fold and 124-fold increases in rifaximin mean Cmax and AUC in healthy subjects.
- darunavir
darunavir increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- dipyridamole
dipyridamole increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- dronedarone
dronedarone increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- elagolix
elagolix will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- eliglustat
eliglustat increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Monitor therapeutic drug concentrations, as indicated, or consider reducing the dosage of the P-gp substrate and titrate to clinical effect.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- erythromycin base
erythromycin base increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- erythromycin ethylsuccinate
erythromycin ethylsuccinate increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- erythromycin lactobionate
erythromycin lactobionate increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- erythromycin stearate
erythromycin stearate increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- etravirine
etravirine increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- fostamatinib
fostamatinib will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Concomitant use of fostamatinib may increase concentrations of P-gp substrates. Monitor for toxicities of the P-gp substrate drug that may require dosage reduction when given concurrently with fostamatinib.
- glecaprevir/pibrentasvir
glecaprevir/pibrentasvir will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- grapefruit
grapefruit increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- istradefylline
istradefylline will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.
- itraconazole
itraconazole increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- ivacaftor
ivacaftor increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Ivacaftor and its M1 metabolite has the potential to inhibit P-gp; may significantly increase systemic exposure to sensitive P-gp substrates with a narrow therapeutic index.
- ketoconazole
ketoconazole increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- lapatinib
lapatinib increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- letermovir
letermovir increases levels of rifaximin by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- levoketoconazole
levoketoconazole increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- lomitapide
lomitapide increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- lonafarnib
lonafarnib will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Lonafarnib is a weak P-gp inhibitor. Monitor for adverse reactions if coadministered with P-gp substrates where minimal concentration changes may lead to serious or life-threatening toxicities. Reduce P-gp substrate dose if needed.
- lopinavir
lopinavir increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- mefloquine
mefloquine increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- metoclopramide intranasal
rifaximin will decrease the level or effect of metoclopramide intranasal by Other (see comment). Use Caution/Monitor. Coadministration of metoclopramide intranasal with drugs that impair GI motility may decrease systemic absorption of metoclopramide. Monitor for reduced therapeutic effect.
- nelfinavir
nelfinavir increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- nicardipine
nicardipine increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- nifedipine
nifedipine increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- nilotinib
nilotinib increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- paliperidone
paliperidone increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- ponatinib
ponatinib increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- posaconazole
posaconazole increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- progesterone micronized
progesterone micronized increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- propafenone
propafenone increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- propranolol
propranolol increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- quinidine
quinidine increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- quinine
quinine increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- ranolazine
ranolazine increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- ritonavir
ritonavir increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- saquinavir
saquinavir increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- sarecycline
sarecycline will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor for toxicities of P-gp substrates that may require dosage reduction when coadministered with P-gp inhibitors.
- sodium picosulfate
rifaximin decreases effects of sodium picosulfate by altering metabolism. Use Caution/Monitor. Coadministration with antibiotics decreases efficacy by altering colonic bacterial flora needed to convert sodium picosulfate to active drug.
- stiripentol
stiripentol will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Consider reducing the dose of P-glycoprotein (P-gp) substrates, if adverse reactions are experienced when administered concomitantly with stiripentol.
- sunitinib
sunitinib increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- tacrolimus
tacrolimus increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- tamoxifen
tamoxifen increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- ticagrelor
ticagrelor increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- tucatinib
tucatinib will increase the level or effect of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Consider reducing the dosage of P-gp substrates, where minimal concentration changes may lead to serious or life-threatening toxicities.
- ulipristal
ulipristal increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- vandetanib
vandetanib increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- vemurafenib
vemurafenib increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- verapamil
verapamil increases levels of rifaximin by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
Minor (0)
Adverse Effects
>10%
Flatulence (11%)
1-10%
Headache (10%)
Rectal tenesmus (7%)
Abdominal pain (7%)
Defecation urgency (6%)
Nausea (5%)
Constipation (4%)
Pyrexia (3%)
Vomiting (2%)
Frequency Not Defined
Hypersensitivity reactions (including allergic dermatitis)
Pruritus
Rash
Rhabdomyolysis (patients with cirrhosis)
Severe cutaneous adverse reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in patients with cirrhosis
Warnings
Contraindications
Hypersensitivity to rifamycin antibiotics
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
Coadministration with P-gp inhibitors substantially increases systemic exposure to rifaximin; coadministration of cyclosporine with rifaximin resulted in 83-fold and 124-fold increases in rifaximin mean Cmax and AUC in healthy subjects
Pregnancy & Lactation
Pregnancy category: C
Lactation: Do not use if nursing or do not nurse
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Antimicrobial action is a result of binding to the beta-subunit of bacterial DNA-dependent RNA polymerase, resulting in inhibition of transcription
Hepatic encephalopathy: Inhibits growth of enteric ammonia-producing bacteria to indirectly reduce serum ammonia level
Irritable bowel syndrome with diarrhea: The exact mechanism of action for IBS-D is not known, but is thought to be related to changes in the bacterial content in the gastrointestinal tract and reduction of gas
Absorption
Bioavailability: <0.4%
Peak plasma time: 1 hr
Distribution
Gut: 80-90%
Metabolism
Induces CYP3A4 in hepatocytes in vitro
Elimination
Half-life: 2-5 hr
Excretion: Feces (>90%)
Administration
Instructions
May take with or without food
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| Xifaxan oral - | 200 mg tablet |  | |
| Xifaxan oral - | 550 mg tablet |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
rifaximin oral
RIFAXIMIN - ORAL
(rif-AX-i-min)
COMMON BRAND NAME(S): Xifaxan
USES: This medication is used to treat diarrhea caused by the common bacteria known as E. coli ("traveler's diarrhea"). Rifaximin should not be used if you have a fever or bloody diarrhea. It works by stopping the growth of bacteria.This antibiotic treats only bacterial infections. It will not work for viral infections (such as common cold, flu). Using any antibiotic when it is not needed can cause it to not work for future infections.Rifaximin is also used to treat irritable bowel syndrome with diarrhea. It is also used to prevent a brain problem caused by liver disease (hepatic encephalopathy). It may help you think more clearly.
HOW TO USE: Read the Patient Information Leaflet if available from your pharmacist before you start taking rifaximin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.The dosage is based on your medical condition and response to treatment.To treat traveler's diarrhea, take this medication by mouth with or without food as directed by your doctor, usually 3 times a day (every 8 hours) for 3 days.To treat irritable bowel syndrome with diarrhea, take this medication by mouth with or without food as directed by your doctor, usually 3 times a day for 14 days.To prevent hepatic encephalopathy, take this medication by mouth with or without food as directed by your doctor, usually 2 times a day (every 12 hours).For the best effect, take this antibiotic at evenly spaced times. To help you remember, take this medication at the same time(s) every day.For traveler's diarrhea, continue to take this medication until the full prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may result in a return of the infection.Tell your doctor if you are still having diarrhea after 1 to 2 days, if you have bloody diarrhea, or if you have a fever along with the diarrhea. Tell your doctor if your condition does not improve or if it worsens.
SIDE EFFECTS: Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.This medication may rarely cause a severe intestinal condition due to a bacteria called C. difficile. This condition may occur during treatment or weeks to months after treatment has stopped. Tell your doctor right away if you develop: diarrhea that doesn't stop, abdominal or stomach pain/cramping, blood/mucus in your stool.If you have these symptoms, do not use anti-diarrhea or opioid products because they may make symptoms worse.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking rifaximin, tell your doctor or pharmacist if you are allergic to it; or to other rifamycins (rifampin, rifabutin); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history.Rifaximin may cause live bacterial vaccines (such as typhoid vaccine) to not work well. Tell your health care professional that you are using rifaximin before having any immunizations/vaccinations.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.It is unknown if this drug passes into breast milk. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: Do not share this medication with others.This medication has been prescribed for your current condition only. Do not use it later for another infection unless your doctor tells you to.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised October 2021. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
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