alosetron vs nizatidine
Side-by-side comparison of alosetron and nizatidine Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Lotronex
Axid
Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS). It helps to reduce diarrhea and stomach pain.
Nizatidine helps reduce stomach acid. It can treat ulcers and heartburn.
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.
Nizatidine can treat active duodenal ulcers for up to 8 weeks. It can also be used long-term at a lower dose to prevent ulcers from returning. Nizatidine treats esophagitis (damage to the esophagus) and heartburn caused by GERD for up to 12 weeks. It can also treat active benign gastric ulcers for up to 8 weeks.
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.
Nizatidine is an H2 receptor antagonist. This means it blocks histamine from attaching to cells in your stomach. By blocking histamine, the drug reduces the amount of acid your stomach makes.
- • Constipation
- • Abdominal discomfort and pain
- • Nausea
- • Gastrointestinal discomfort and pain
- • Headache
- • Abdominal pain
- • Diarrhea
- • Nausea
- • 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
- Long-term kidney disease 264
- Sudden kidney damage 161
- Kidney failure 135
- Final stage of kidney disease 72
- Feeling sick to your stomach 67
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.
If you have kidney problems, your doctor may need to lower your dose. Before taking this medicine for a stomach ulcer, make sure it is not cancerous.
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.
Tell your doctor if you are pregnant or plan to become pregnant. It is not known if nizatidine will harm your unborn baby. Talk to your doctor if you are breastfeeding.
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How to Read This alosetron vs nizatidine Comparison
alosetron is classified in the 5-HT3 Antagonist (IBS-D) drug class, while nizatidine sits within the H2 Receptor Antagonist 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 nizatidine has 699. 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 nizatidine — 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.