PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

alosetron vs lansoprazole

Side-by-side comparison of alosetron and lansoprazole 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)
lansoprazole Proton Pump Inhibitor (PPI)
Type
alosetron Prescription
lansoprazole Over-the-Counter
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.

lansoprazole

Lansoprazole is a medicine that reduces the amount of acid in your stomach. It belongs to a class of drugs called proton pump inhibitors (PPIs).

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.

lansoprazole

Lansoprazole can treat several conditions caused by too much stomach acid. It can heal duodenal and gastric ulcers. It also treats heartburn (GERD) and a damaged esophagus (erosive esophagitis).

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.

lansoprazole

Lansoprazole works by blocking the enzyme in the stomach that produces acid. This helps to lower the amount of acid made. Lowering acid helps to heal damage and relieve symptoms.

Common Side Effects
alosetron
  • Constipation
  • Abdominal discomfort and pain
  • Nausea
  • Gastrointestinal discomfort and pain
lansoprazole
  • Diarrhea
  • Abdominal pain
  • Nausea
  • Constipation
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
lansoprazole
  • Long-term kidney disease 32,775
  • Sudden kidney damage 18,670
  • Kidney failure 13,811
  • Kidney failure requiring dialysis 9,782
  • Kidney damage 9,520
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.

lansoprazole

Lansoprazole may hide the symptoms of stomach cancer. If you have a poor response or early return of symptoms, your doctor may do more tests. Long-term use of PPIs like lansoprazole may increase your risk of bone fractures. It may also cause low magnesium levels or Vitamin B-12 deficiency.

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.

lansoprazole

Talk to your doctor if you are pregnant or plan to become pregnant. Lansoprazole may affect bone development in the fetus. If you take lansoprazole with clarithromycin, also consider clarithromycin's pregnancy risks.

Also Compare — Nearby Drugs

How to Read This alosetron vs lansoprazole Comparison

alosetron is classified in the 5-HT3 Antagonist (IBS-D) drug class, while lansoprazole sits within the Proton Pump Inhibitor (PPI) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are split between OTC and prescription status, which affects access and supervision.

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 lansoprazole has 84,558. 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 lansoprazole — 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.