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alosetron vs metoclopramide

Side-by-side comparison of alosetron and metoclopramide Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

Drug Class
alosetron 5-HT3 Antagonist (IBS-D)
metoclopramide Prokinetic / Antiemetic
Type
alosetron Prescription
metoclopramide Prescription
Summary
alosetron

Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS). It helps to reduce diarrhea and stomach pain.

metoclopramide

Metoclopramide is a drug that helps with stomach problems. It can help food move faster through your stomach and reduce nausea.

What It Treats
alosetron

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.

metoclopramide

This medicine treats heartburn caused by acid reflux when other treatments don't work. It also helps with symptoms of slow stomach emptying in people with diabetes, like nausea, vomiting, and feeling full. This medicine is for adults and should not be used for more than 12 weeks.

How It Works
alosetron

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.

metoclopramide

Metoclopramide helps your stomach muscles move faster. This helps food empty from your stomach more quickly. It also blocks a chemical in your brain that causes nausea.

Common Side Effects
alosetron
  • Constipation
  • Abdominal discomfort and pain
  • Nausea
  • Gastrointestinal discomfort and pain
metoclopramide
  • Restlessness
  • Drowsiness
  • Fatigue
  • Feeling tired
FAERS Reports
alosetron
  • 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
metoclopramide
  • Uncontrollable muscle movements 13,205
  • Movement problems 11,628
  • Problem with the brain or nerves 7,175
  • Muscle spasms 6,661
  • Pain 4,665
Serious Warnings
alosetron

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.

metoclopramide

Metoclopramide can cause a serious movement disorder called tardive dyskinesia. This may not go away even after you stop taking the medicine. The risk of tardive dyskinesia increases with long-term use and high doses. Call your doctor right away if you have uncontrolled muscle movements.

Pregnancy
alosetron

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.

metoclopramide

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if this medicine will harm your unborn baby. Talk to your doctor about the risks and benefits of taking this medicine while breastfeeding.

How to Read This alosetron vs metoclopramide Comparison

alosetron is classified in the 5-HT3 Antagonist (IBS-D) drug class, while metoclopramide sits within the Prokinetic / Antiemetic 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 metoclopramide has 43,334. 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 metoclopramide — 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.