Over-the-counter medication · H2 Receptor Antagonist
nizatidine
Also sold as Axid. Nizatidine can treat active duodenal ulcers for up to 8 weeks.
Data updated 2026-05-15
- 1,480
- FDA reportsRarely reported
- 2
- InteractionsFew interactions
- $0.90
- Generic price (NADAC)
What the data shows
nizatidine (Axid) is an over-the-counter H2 Receptor Antagonist, among the least-reported drugs the FDA tracks (1,480 FDA reports), with 2 documented drug interactions.
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
nizatidine (Axid) is an over-the-counter H2 Receptor Antagonist. Nizatidine can treat active duodenal ulcers for up to 8 weeks.
Nizatidine helps reduce stomach acid. It can treat ulcers and heartburn.
Verify with FDA → · CMS NADAC pricing →
Drug Pricing (NADAC)
Generic Price
$0.90/unit
Generic Available
Yes (4 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Nizatidine can treat active duodenal ulcers for up to 8 weeks.
Common side effects
Headache, Abdominal pain, Diarrhea
Key warnings
If you have kidney problems, your doctor may need to lower your dose.
The sections below are summarized in plain English from nizatidine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
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.
How to Take It
For an active duodenal ulcer, take 300 mg once a day at bedtime, or 150 mg twice a day. To prevent ulcers, take 150 mg once a day at bedtime. For GERD, take 150 mg twice a day. For an active benign gastric ulcer, take 150 mg twice a day or 300 mg once a day at bedtime.
This is a plain-language summary of nizatidine's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
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.
This is a plain-language summary of nizatidine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of nizatidine's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store at room temperature, between 68° to 77°F, in a tightly closed container away from light.
Side Effects (from patient reports)
Based on 1,480 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for nizatidine, by number of reports
- Long-term kidney disease
Long-term kidney disease
264 reports
- Sudden kidney damage
Sudden kidney damage
161 reports
- Kidney failure
Kidney failure
135 reports
- Final stage of kidney disease 72
Final stage of kidney disease
72 reports
- Feeling sick to your stomach 67
Feeling sick to your stomach
67 reports
- Throwing up 66
Throwing up
66 reports
- Kidney damage 59
Kidney damage
59 reports
- GERD, acid reflux 56
GERD, acid reflux
56 reports
- Shortness of breath 53
Shortness of breath
53 reports
- Loose stools 48
Loose stools
48 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for nizatidine each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where nizatidine sits
nizatidine has more FDA adverse-event reports than 9% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is nizatidine; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 1,480 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 1999–2025.
Total Reports
1,480
Reports Mentioning Death
157
10.6% of reports — not proof of cause
Hospitalization Reports
566
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | CHRONIC KIDNEY DISEASE | 264 |
| 2 | ACUTE KIDNEY INJURY | 161 |
| 3 | RENAL FAILURE | 135 |
| 4 | END STAGE RENAL DISEASE | 72 |
| 5 | NAUSEA | 69 |
| 6 | VOMITING | 66 |
| 7 | RENAL INJURY | 59 |
| 8 | GASTROOESOPHAGEAL REFLUX DISEASE | 56 |
| 9 | DYSPNOEA | 53 |
| 10 | DIARRHOEA | 48 |
| 11 | PYREXIA | 48 |
| 13 | DIZZINESS | 45 |
| 14 | MALAISE | 45 |
| 15 | ANAEMIA | 44 |
| 16 | FATIGUE | 42 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
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.
Known Drug Interactions
albuterol, systemic and inhaled mebendazole amoxicillin medroxyprogesterone ampicillin, with or without sulbactam methylprednisolone atenolol metronidazole azithromycin metoprolol caffeine, dietary ingestion nadolol cefaclor nifedipine co-trimoxazole (trimethoprim and sulfamethoxazole) nizatidine diltiazem norfloxacin dirithromycin ofloxacin enflurane omeprazole famotidine prednisone, prednisolone felodipine ranitidine finasteride rifabutin hydrocortisone roxithromycin isoflurane Sorbitol (purgative doses do not inhibit theophylline absorption) isoniazid sucralfate isradipine terbutaline,...
Mechanism: Nizatidine may interfere with the way your body breaks down theophylline, potentially increasing the risk of side effects.
What to do: Watch for signs of too much medicine, such as nausea or a racing heart, and report them to your healthcare provider.
Nizatidine) — An increase in gastric pH resulting from administration of nizatidine had no significant effect on pharmacokinetics.
Mechanism: Nizatidine changes the acid levels in the stomach, but this does not change how the body absorbs or uses tadalafil.
What to do: No special changes are needed when taking these two medicines together.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I take nizatidine with food?
How long does it take for nizatidine to heal an ulcer?
Can I take nizatidine long-term?
What should I do if I experience side effects?
Can nizatidine be used for children?
Does nizatidine interact with other medications?
Can I drink alcohol while taking nizatidine?
Is nizatidine available over the counter?
What do the numbers on the capsules mean?
What if my heartburn doesn't get better?
What are the common side effects of nizatidine?
Does nizatidine interact with other medications?
What drug class is nizatidine?
Is nizatidine safe during pregnancy?
Related Medications in H2 Receptor Antagonist
Other drugs grouped near nizatidine - same-class peers and common alternatives.
alosetron
Lotronex
Alosetron (Lotronex) is a medicine for women with severe diarrhea-predominant irritable bowel syndrome (IBS).
Compare with nizatidine →
aprepitant
Emend
Aprepitant (Emend) is a medicine that helps prevent nausea and vomiting.
Compare with nizatidine →
bisacodyl
Dulcolax
Bisacodyl is a medicine that helps you have a bowel movement.
Compare with nizatidine →
bismuth subsalicylate
Pepto-Bismol
Bismuth subsalicylate (Pepto-Bismol) is a medicine that can treat diarrhea and upset stomach.
Compare with nizatidine →
cimetidine
Tagamet
Cimetidine (Tagamet) reduces stomach acid.
Compare with nizatidine →
Medication Guides
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Common Drug Interactions
Dangerous medication combinations and how to protect yourself
What the FDA Data Shows for nizatidine
The FDA label for nizatidine (sold under brand names such as Axid) classifies it as an over-the-counter product in the H2 Receptor Antagonist class. Nizatidine can treat active duodenal ulcers for up to 8 weeks. Official labeling lists 6 commonly reported side effects, including Headache, Abdominal pain, Diarrhea.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 1,480 voluntary reports. The database also lists 2 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated major severity. NADAC pricing from CMS shows a generic unit cost of $0.90.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: June 30, 2022
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages