alosetron vs rifaximin
Side-by-side comparison of alosetron and rifaximin Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS). It helps to reduce diarrhea and stomach pain.
Xifaxan is an antibiotic medicine. It helps treat traveler's diarrhea and irritable bowel syndrome with diarrhea (IBS-D). It also lowers the risk of hepatic encephalopathy (HE) coming back.
Alosetron is used to treat severe diarrhea-predominant irritable bowel syndrome (IBS) in women. It is for women whose IBS symptoms have lasted for 6 months or longer. You should have already ruled out other possible causes of your symptoms. This medicine is only for you if other treatments have not worked well enough.
Xifaxan can treat traveler's diarrhea caused by certain germs in adults and kids 12 and older. It can also lower the risk of hepatic encephalopathy (HE) returning in adults. Xifaxan is also used to treat irritable bowel syndrome with diarrhea (IBS-D) in adults.
Alosetron blocks a substance called serotonin in your gut. Serotonin can speed up bowel movements. By blocking serotonin, alosetron slows down your bowel and reduces diarrhea.
Xifaxan is an antibiotic that works in your gut. It stops the growth of certain bacteria that can cause diarrhea or other problems. It also reduces the amount of ammonia in your body, which can help with HE.
- • Constipation
- • Abdominal discomfort and pain
- • Nausea
- • Gastrointestinal discomfort and pain
- • Headache
- • Swelling in your legs or ankles
- • Nausea
- • Constipation
- • Dizziness
- Medicine not working 11
- Diarrhea 10
- Feeling sick to your stomach 8
- Using the medicine for something it's not approved for 7
- Stomach pain 6
- Death 3,982
- Hospitalization 1,704
- Diarrhea 1,193
- Using the medicine for a condition it is not approved for 1,133
- Treatment stopped 989
Alosetron can cause serious gut problems, like ischemic colitis (reduced blood flow to the bowel) and severe constipation. These problems can lead to hospitalization, surgery, or even death. Stop taking alosetron right away if you get constipated or have symptoms of ischemic colitis, like bloody diarrhea or bad stomach pain. Call your doctor immediately.
Xifaxan may not work if you have a fever or blood in your stool. It may also not work for diarrhea caused by germs other than E. coli. If your diarrhea gets worse or lasts more than 1-2 days, stop taking Xifaxan and talk to your doctor. Diarrhea caused by C. difficile can happen with almost all antibiotics, including Xifaxan. Use Xifaxan with caution if you have severe liver problems.
It is not known if alosetron can harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if alosetron passes into breast milk. Talk to your doctor about the best way to feed your baby if you take alosetron.
Xifaxan may harm your unborn baby. Tell your doctor if you are pregnant or plan to become pregnant. It is not known if Xifaxan passes into breast milk, so talk to your doctor about the best way to feed your baby if you take Xifaxan.
How to Read This alosetron vs rifaximin Comparison
alosetron is classified in the 5-HT3 Antagonist (IBS-D) drug class, while rifaximin sits within the Non-Systemic Antibiotic (IBS-D) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, alosetron has 42 submissions while rifaximin has 9,001. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between alosetron and rifaximin — always consult your physician or pharmacist first.
Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.