alosetron vs diphenoxylate/atropine
Side-by-side comparison of alosetron and diphenoxylate/atropine Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Lotronex
Lomotil
Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS). It helps to reduce diarrhea and stomach pain.
Lomotil is a drug that helps manage diarrhea. It contains two medicines, diphenoxylate and atropine, to slow down your bowels.
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.
Lomotil is used to treat diarrhea in people 13 years and older. It is used along with other treatments. Make sure you drink enough fluids and get electrolytes while taking Lomotil.
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.
Lomotil works by slowing down the movement of your intestines. Diphenoxylate reduces bowel contractions. Atropine is added to discourage people from taking too much of this medicine.
- • Constipation
- • Abdominal discomfort and pain
- • Nausea
- • Gastrointestinal discomfort and pain
- • Numbness in your arms and legs
- • Feeling of well-being
- • Depression
- • Feeling tired or weak
- • Confusion
- 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
No adverse event reports.
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.
Lomotil can cause serious side effects, including breathing problems and nervous system issues. Dehydration and electrolyte imbalance can also occur. If you have an infection causing your diarrhea, Lomotil can make it worse. Do not use if you are under 6 years old.
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.
It is not known if Lomotil can harm your unborn baby. Talk to your doctor if you are pregnant or plan to become pregnant. It is also not known if Lomotil passes into breast milk, so talk to your doctor if you are breastfeeding.
How to Read This alosetron vs diphenoxylate/atropine Comparison
alosetron is classified in the 5-HT3 Antagonist (IBS-D) drug class, while diphenoxylate/atropine sits within the Antidiarrheal Combination 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 diphenoxylate/atropine has 0. 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 diphenoxylate/atropine — 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.