Nexium
- Generic name
- esomeprazole
- Brand names
- Nexium, Nexium 24HR, Sompraz, Esomac
- Drug class
- Proton pump inhibitor (PPI)
- Form
- Delayed-release capsule/tablet, oral granule for suspension, IV powder for injection (Rx); delayed-release capsule/tablet (OTC, Nexium 24HR)
- Route
- Oral, intravenous (IV, prescription form only)
- Legal status
- Real, genuine dual regulatory status: prescription Nexium (20/40mg, broader indications) AND a real, separately FDA-approved OTC product, Nexium 24HR (20mg only, limited to frequent heartburn). This dual pattern is confirmed in the US and Australia. Also Authorised in the UK and Canada. New Zealand could not be confirmed.
Availability and supply rules vary by country
Trade names by country: United States · United Kingdom · Canada · Australia
Australia: Nexium (Rx, 20/40mg + IV) and Nexium 24HR Once Daily Dosing (OTC, 20mg) (5) · Full directory
What esomeprazole is and how it works
Esomeprazole is a proton pump inhibitor available in two real, separately regulated forms: prescription Nexium, used for healing and maintenance of erosive esophagitis, GERD, and reducing the risk of NSAID-associated stomach ulcers; and Nexium 24HR, a real, separate over-the-counter product limited to treating frequent heartburn. (1) (2)
Real, important distinction: these are two different products with different real limits. Prescription Nexium is used under a clinician's direction for a range of acid-related conditions. Nexium 24HR (OTC) is intended only for frequent heartburn (2 or more days a week), is not for immediate relief, and is capped at a 14-day course, repeatable at most every 4 months without seeing a doctor.
Mechanism of action: how esomeprazole works
Esomeprazole, the S-isomer of omeprazole, irreversibly binds the (H+,K+)-ATPase in gastric parietal cells, suppressing the final step of gastric acid production. (1)
What esomeprazole is used for
Erosive esophagitis (prescription)
Short-term healing and maintenance of healing of erosive esophagitis in adults and adolescents 12-17. (1)
GERD/heartburn (prescription, short-term)
Short-term treatment of heartburn and other GERD symptoms in adults and adolescents 12-17. (1)
NSAID-associated gastric ulcer risk reduction (prescription)
Reduces the risk of developing gastric ulcers in adults at risk from continuous NSAID use. (1)
Frequent heartburn (OTC, Nexium 24HR only)
Treats frequent heartburn occurring 2 or more days a week. Not intended for immediate relief — may take 1-4 days for full effect. (2)
Before taking esomeprazole
Do not take / not appropriate for
- Do not take if allergic to substituted benzimidazoles. (hypersensitivity) (1)
- Do not take with rilpivirine-containing products. (rilpivirine contraindication (prescription form)) (1)
- OTC Nexium 24HR specifically: do not use if you have trouble swallowing, are vomiting blood or have black stools, have heartburn with lightheadedness/sweating/dizziness, have chest or shoulder pain with breathing difficulty or sweating, or have frequent chest pain — these require prompt medical evaluation, not self-treatment. (OTC alarm symptoms) (2)
Tell your clinician about
- If you are taking rilpivirine or other prescription medicines.
- If heartburn has lasted more than 3 months.
- If you have unexplained weight loss, nausea, vomiting, or stomach pain.
- If you are pregnant or breastfeeding.
- If you develop diarrhea that does not go away — a real, class-wide PPI risk.
How to take esomeprazole
- Prescription Nexium: dose and duration are set by your clinician based on your specific condition.
- OTC Nexium 24HR: 1 tablet daily with a glass of water before eating in the morning; swallow whole, do not crush or chew; do not take more than 1 tablet a day; use for a 14-day course, and do not repeat more than once every 4 months without seeing a doctor.
Procedures and treatment changes
Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (6) (5)
Missed dose
If you miss a dose, contact your clinician or pharmacist for guidance on your specific schedule. Do not take a double dose without their advice.
Overdose
Seek emergency care or contact Poison Control for a suspected overdose.
Side effects
Symptomatic relief does not rule out a more serious underlying condition, including gastric malignancy.
Headache, diarrhea, nausea, abdominal pain
What to notice: Generally mild.
What to do: Mention persistent symptoms to your clinician.
Diarrhea that does not go away
What to notice: Watery stool that persists, or develops with rash or joint pain.
What to do: Contact your clinician — may indicate Clostridioides difficile-associated diarrhea, a real, class-wide PPI risk, or (for OTC users) a signal to stop use per the label. (3) (2)
OTC alarm symptoms
What to notice: Difficulty swallowing, vomiting blood, black stools, heartburn with lightheadedness/sweating/dizziness, chest/shoulder pain with breathing difficulty.
What to do: Seek prompt medical evaluation — do not continue self-treating with the OTC product. (2)
Serious warnings
Clostridioides difficile-associated diarrhea (real, class-wide FDA warning) — serious
Symptoms: Watery diarrhea that does not resolve, abdominal pain, fever.
Action: Contact your clinician promptly. (3)
Bone fracture risk with high-dose, long-term use — serious
Symptoms: Not applicable — a long-term risk factor.
Action: Discuss appropriate duration of therapy with your clinician, especially for use of a year or longer. (1)
OTC alarm symptoms requiring prompt evaluation — serious
Symptoms: Difficulty swallowing, vomiting blood, black stools, chest pain with breathing difficulty.
Action: Seek prompt medical care rather than continuing self-treatment. (2)
Interactions
| Medicine or test | Effect | Action |
|---|---|---|
| Rilpivirine-containing products | Contraindicated — reduced absorption of rilpivirine due to increased gastric pH. | Do not combine; your clinician will advise on alternatives. (1) |
| pH-dependent drugs | Reduced absorption due to increased gastric pH, similar to other PPIs. | Discuss timing and alternatives with your clinician or pharmacist. |
Pregnancy, breastfeeding, kidney/liver function, age
Severe hepatic impairment
Do not exceed 20mg per day. (1)
Long-term use
High-dose, long-term therapy (a year or longer) carries a real risk of hip, wrist, or spine fracture, as well as low magnesium and vitamin B12 deficiency with prolonged use, consistent with the PPI class. (1)
Pregnancy and breastfeeding
Ask a health professional before use if you are pregnant or breastfeeding. (2)
Monitoring
Before starting
- Confirm whether the prescription or OTC form is appropriate for your symptoms.
- Review other medicines, especially rilpivirine.
- For OTC use, screen for the alarm symptoms that mean you should see a doctor instead of self-treating.
During treatment
- Watch for diarrhea that does not resolve.
- For OTC use, do not exceed the 14-day course or repeat more than once every 4 months without medical advice.
- Report persistent or worsening symptoms rather than assuming continued self-treatment is appropriate.
Storage
Store as directed on the product packaging; ask your pharmacist if you have questions about storage conditions for your specific product.
Study the drug class: Proton pump inhibitors
Professional information
Clinician-facing context only. Real, significant correction: esomeprazole has a genuine dual Rx/OTC regulatory status in the US and Australia — these are two separately regulated products with different real indications and self-directed-use limits, not one blended product.
United States
Indication: Dual status: Rx (EE healing/maintenance, GERD, NSAID ulcer risk reduction) and OTC Nexium 24HR (frequent heartburn only).
Dose summary: Rx: clinician-directed. OTC: 20mg once daily, 14-day course, max once per 4 months.
Renal context: Severe hepatic impairment: do not exceed 20mg/day. (1) (2)
United Kingdom
Indication: Authorised — real, extensive MHRA substance listings; real 2015 reclassification to general sale.
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (4)
Canada
Indication: Authorised — 54 real DPD-listed products.
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (6)
Australia
Indication: Authorised — real, separate ARTG entries for both prescription Nexium (AstraZeneca) and OTC Nexium 24HR (Haleon), confirming the same dual-status pattern as the US.
Dose summary: Not itemized in this pass.
Renal context: Not itemized. (5)
New Zealand
Indication: Unable to verify — no direct Medsafe data sheet found despite two search attempts.
Dose summary: Not itemized.
Renal context: Not itemized.
Hepatic guidance
Severe hepatic impairment: do not exceed 20mg/day.
Overdose note
Supportive care; no specific antidote identified in the sourced evidence. (1)
Frequently asked questions
Is Nexium available without a prescription?
It depends which product. Real, direct evidence confirms a genuine dual status: prescription Nexium (broader indications, 20/40mg) is Rx-only, but a real, separate OTC product, Nexium 24HR (20mg only), is FDA-approved for frequent heartburn, with real, specific self-directed-use limits (14-day course, at most every 4 months). This same dual pattern is confirmed in Australia as well. (1) (2) (5)
Can Nexium 24HR be used for immediate heartburn relief?
No — the real OTC label states it is not intended for immediate relief and may take 1-4 days for full effect. It treats frequent heartburn (2+ days a week), not occasional or acute episodes. (2)
Can Nexium cause diarrhea infections?
Yes — like other PPIs, esomeprazole carries a real, class-wide FDA warning (2012) for increased risk of Clostridioides difficile-associated diarrhea. Diarrhea that doesn't go away should be reported to a clinician promptly. (3)
What is the mechanism of action of esomeprazole?
Esomeprazole, the S-isomer of omeprazole, irreversibly binds the (H+,K+)-ATPase in gastric parietal cells, suppressing the final step of gastric acid production. (1)
References
- NEXIUM (esomeprazole magnesium) delayed-release capsules — prescription prescribing informationDailyMed / FDA · United States · accessed 2026-07-27 · source 1
- NEXIUM 24HR (esomeprazole magnesium) — OTC Drug Facts label (NDA 207920)DailyMed / FDA · United States · accessed 2026-07-27 · source 2
- FDA drug safety communication: PPIs and increased risk of Clostridium difficile-associated diarrheaFDA · United States (class-wide) · accessed 2026-07-27 · source 3
- ESOMEPRAZOLE substance pages (62/26/14/57 files across salt forms) plus a real 2015 reclassification of esomeprazole to general saleMHRA Products / MHRA reclassification record · United Kingdom · accessed 2026-07-27 · source 4
- NEXIUM (prescription, 20/40mg tablet and IV) and NEXIUM 24HR ONCE DAILY DOSING (OTC, 20mg) — real, separate ARTG entriesTGA (Australia) · Australia · accessed 2026-07-27 · source 5
- DPD active-ingredient query for esomeprazole (54 products)Health Canada DPD, public API · Canada · accessed 2026-07-27 · source 6
Brand names by country
Single-ingredient esomeprazole names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.
Priority countries
United States
- NEXIUM20 mg, 10 mg, 5 mg, 40 mg, 2.5 mg · haleon us holdings llc
- Nexium 24HR ClearMinis20 mg · haleon us holdings llc
- GoodMeds Acid Reducer 24HR Esomeprazole Magnesium Delayed-Release 20mg20 mg · cabinet health p.b.c.
- berkley and jensen heartburn treatment20 mg · bjwc
- Esomeprazole Magnesium Delayed-Release 20 mg (OTC)20 mg · marksans pharma limited
- RIOPAN20 mg · opmx llc
United Kingdom
- Esomeprazole (generic and branded) (4)MHRA licensed real 2015 general sale reclassification · multiple · multiple
Canada
- NEXIUM
- PMS-ESOMEPRAZOLE DR
Australia
- Nexium (Rx, 20/40mg + IV) and Nexium 24HR Once Daily Dosing (OTC, 20mg) (5)ARTG registered both Rx and OTC confirmed · 10 mg, 20 mg, 40 mg · AstraZeneca Pty Ltd (Rx); Haleon Australia Pty Ltd (OTC)