Over-the-counter medication · Proton Pump Inhibitor (PPI)
omeprazole
Also sold as Prilosec. This medicine treats frequent heartburn, which is heartburn that occurs 2 or more days a week.
Data updated 2026-05-15
- 331,875
- FDA reportsHeavily reported
- 27
- InteractionsSeveral interactions
- In shortage
- FDA status
What the data shows
omeprazole (Prilosec) is an over-the-counter Proton Pump Inhibitor (PPI), in the top 5% of tracked drugs by FAERS report volume (331,875 FDA reports), with 27 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.
omeprazole (Prilosec) is an over-the-counter Proton Pump Inhibitor (PPI). This medicine treats frequent heartburn, which is heartburn that occurs 2 or more days a week.
Omeprazole (Prilosec) is a medicine that reduces the amount of acid in your stomach. It belongs to a class of drugs called proton pump inhibitors (PPIs).
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
omeprazole is currently listed as to be discontinued by the FDA. Affected manufacturer: Sandoz Inc..
View all drug shortages →Drug Pricing (NADAC)
Generic Price
$0.07/unit
Generic Available
Yes (30 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
NADAC price trail: OMEPRAZOLE DR 10 MG CAPSULE
Same CMS presentation as the headline generic unit price above (3 effective dates). Adjacent % compares consecutive NADAC releases for this description only, not a patient out-of-pocket quote. Latest step: -3.9% vs prior release.
| Effective | NADAC / unit | vs prior | NDCs |
|---|---|---|---|
| April 17, 2024 | $0.0680/EA | - | 1 |
| October 23, 2024 | $0.0738/EA | +8.5% | 2 |
| December 18, 2024 | $0.0710/EA | -3.9% | 14 |
What it does
This medicine treats frequent heartburn, which is heartburn that occurs 2 or more days a week.
Common side effects
Headache
Key warnings
Children under 18 should ask a doctor before use.
The sections below are summarized in plain English from omeprazole's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
Omeprazole works by blocking the production of acid in your stomach. It does this by targeting the cells that make stomach acid. This helps to reduce heartburn symptoms.
Side Effects (from patient reports)
Based on 331,875 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for omeprazole, by number of reports
- Fatigue
Fatigue
19,901 reports
- Nausea
Nausea
19,842 reports
- Diarrhoea
Diarrhoea
19,627 reports
- Dyspnoea
Dyspnoea
16,336 reports
- Headache
Headache
14,629 reports
- Pain
Pain
13,759 reports
- Chronic Kidney Disease
Chronic Kidney Disease
13,547 reports
- Vomiting
Vomiting
13,263 reports
- Dizziness
Dizziness
13,108 reports
- Acute Kidney Injury
Acute Kidney Injury
11,753 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 omeprazole 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 omeprazole sits
omeprazole has more FDA adverse-event reports than 98% 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 omeprazole; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 331,875 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 1999–2025.
Total Reports
331,875
Reports Mentioning Death
30,378
9.2% of reports — not proof of cause
Hospitalization Reports
122,601
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | FATIGUE | 19,901 |
| 2 | NAUSEA | 19,842 |
| 3 | DIARRHOEA | 19,627 |
| 4 | DYSPNOEA | 16,336 |
| 6 | HEADACHE | 14,629 |
| 7 | PAIN | 13,759 |
| 8 | CHRONIC KIDNEY DISEASE | 13,547 |
| 9 | VOMITING | 13,263 |
| 10 | DIZZINESS | 13,108 |
| 12 | ACUTE KIDNEY INJURY | 11,753 |
| 13 | MALAISE | 10,918 |
| 14 | ASTHENIA | 10,698 |
| 15 | ARTHRALGIA | 10,694 |
| 16 | FALL | 10,630 |
| 17 | PNEUMONIA | 9,856 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Children under 18 should ask a doctor before use. Heartburn in children may be a sign of a serious condition.
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: Omeprazole does not change how fast your body breaks down and gets rid of theophylline.
Proton Pump Inhibitors: Omeprazole No Dose Adjustment Omeprazole: The mean 24-hour gastric pH value was 5.2 when omeprazole was administered alone and 5.7 when coadministered with clarithromycin as a result of increased omeprazole exposures [see Pharmacokinetics ( 12.3 )] (see also Omeprazole under “Drugs That Affect Clarithromycin Tablets” in the table below). Saquinavir (in patients with normal renal function) Ritonavir (in patients with normal renal function) No Dose Adjustment Proton Pump Inhibitors: Omeprazole Use With Caution Omeprazole: Clarithromycin concentrations in the gastric...
Mechanism: Clarithromycin slows down how your body processes omeprazole, which leads to higher levels of the stomach medicine in your system.
Omeprazole or Esomeprazole Avoid concomitant use of clopidogrel with omeprazole or esomeprazole. In clinical studies, omeprazole was shown to reduce significantly the antiplatelet activity of clopidogrel when given concomitantly or 12 hours apart. A similar reduction in antiplatelet activity was observed with esomeprazole when given concomitantly with clopidogrel.
Mechanism: Omeprazole stops clopidogrel from working correctly by preventing it from turning into its active form. This makes the medicine less effective at stopping blood clots.
Proton pump inhibitor: omeprazole ↓ omeprazole ↔ darunavir When omeprazole is co-administered with darunavir/ritonavir, monitor patients for decreased efficacy of omeprazole. Consider increasing the omeprazole dose in patients whose symptoms are not well controlled; avoid use of more than 40 mg per day of omeprazole.
Mechanism: Darunavir can lower the amount of omeprazole in your body, making the stomach medicine less effective at treating acid. This happens because of how the drugs interact during processing in the body.
Mild or Moderate CYP3A Inhibitors: Clotrimazole, antibiotics (e.g., verapamil, diltiazem, nifedipine, nicardipine), amiodarone, danazol, ethinyl estradiol, cimetidine, lansoprazole and omeprazole May increase tacrolimus whole blood trough concentrations and increase the risk of serious adverse reactions (e.g., neurotoxicity, QT prolongation) [see Warnings and Precautions ( 5.7 , 5.10 , 5.11 )] .
Mechanism: Omeprazole slows down the process your body uses to remove tacrolimus, which can cause the drug to reach risky levels in your blood.
This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.
Common Questions
How long does it take for omeprazole to work?
Can I take more than 1 tablet a day?
How often can I repeat a 14-day course of treatment?
Can children take this medicine?
Should I take this medicine with food?
What should I do if I still have heartburn after 14 days?
Can I chew or crush the tablet?
What if I miss a dose?
Can I take this medicine for immediate relief of heartburn?
What should I tell my doctor before taking this medicine?
What are the common side effects of omeprazole?
Does omeprazole interact with other medications?
What drug class is omeprazole?
What pregnancy or breastfeeding source fields are listed for omeprazole?
Has omeprazole been recalled?
Is omeprazole currently in shortage?
Active Recalls
Presence of foreign tablets/capsules: presence of foreign Divalproex Sodium Extended-Release 250mg tablet in a bottle of omeprazole capsules.
Dr. Reddy's Laboratories, Inc.
Related Medications in Proton Pump Inhibitor (PPI)
Other drugs grouped near omeprazole - 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 omeprazole →
aprepitant
Emend
Aprepitant (Emend) is a medicine that helps prevent nausea and vomiting.
Compare with omeprazole →
bisacodyl
Dulcolax
Bisacodyl is a medicine that helps you have a bowel movement.
Compare with omeprazole →
bismuth subsalicylate
Pepto-Bismol
Bismuth subsalicylate (Pepto-Bismol) is a medicine that can treat diarrhea and upset stomach.
Compare with omeprazole →
cimetidine
Tagamet
Cimetidine (Tagamet) reduces stomach acid.
Compare with omeprazole →
Compare beyond drug class
Nationwide peers by FAERS volume & death-report share
Two PlainMeds-derived comparison paths for omeprazole: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.
Similar FAERS report volume
Nearest drugs by total FAERS reports. This record: 331,875.
Similar death-report share
Nearest drugs by FAERS death-report share. This record: 9.15%.
- celecoxib Δ 0.01 pts · 128,099 reports · COX-2 Selective NSAID 9.16%death share
- folic acid Δ 0.02 pts · 241,433 reports · B Vitamin (Folate) Supplement 9.17%death share
- meclizine Δ 0.02 pts · 15,616 reports · Antihistamine / Antiemetic 9.13%death share
- ivermectin Δ 0.06 pts · 5,936 reports · Antiparasitic 9.10%death share
Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Pain Relievers Compared
NSAIDs vs acetaminophen, which OTC pain reliever to use
Narrow Therapeutic Index Drugs
FDA bioequivalence and label-record context for narrow therapeutic index medicines
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
What the FDA Data Shows for omeprazole
The FDA label for omeprazole (sold under brand names such as Prilosec) classifies it as an over-the-counter product in the Proton Pump Inhibitor (PPI) class. This medicine treats frequent heartburn, which is heartburn that occurs 2 or more days a week. Official labeling lists 1 commonly reported side effect, including Headache.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 331,875 voluntary reports. The database also lists 27 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 $0.07.
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 (currently 1 recall record on file), and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.
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). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.
Last updated: November 10, 2024
PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.
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 from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.
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