Nexium is the original brand name for esomeprazole, a proton pump inhibitor that reduces stomach acid. It treats reflux, heartburn, oesophagitis and stomach ulcers. No product called Nexium appears in the South African register, but esomeprazole is registered here under several other names.
What is Nexium?
A search of the South African Medicine Price Registry returns no product called Nexium. What it does contain is esomeprazole, under names including Nectizole, Nextell OTC, and several generic products, at 20 mg and 40 mg.
Nexium is the internationally recognised originator brand of esomeprazole, which is why the name is familiar even where the product is not on the shelf. If you are looking for Nexium in South Africa, any registered esomeprazole product is the same medicine.
The strengths people search for — 10 mg, 20 mg and 40 mg — reflect the international range. 20 mg and 40 mg are the usual adult strengths; 10 mg is a paediatric or low-dose form.
Esomeprazole is a proton pump inhibitor (PPI). Cells lining the stomach produce acid using an enzyme pump, and esomeprazole shuts those pumps down irreversibly — acid production only recovers as the cell builds new ones.
Its relationship to omeprazole is worth understanding. Omeprazole exists as two mirror-image forms; esomeprazole is the S-form isolated. It is metabolised slightly more slowly, giving somewhat higher and more consistent blood levels. In practice the two are very close, and the clinical difference is modest — meaningful in severe oesophagitis, marginal for everyday reflux. A doctor switching you between them is not downgrading your treatment.
What is Nexium commonly used for?
- Gastro-oesophageal reflux disease (GORD) — persistent heartburn and acid regurgitation.
- Erosive oesophagitis — inflammation and ulceration of the food pipe. This is where esomeprazole’s evidence is strongest.
- Stomach and duodenal ulcers, treatment and prevention.
- Preventing ulcers in people on long-term anti-inflammatories.
- Helicobacter pylori eradication, with two antibiotics.
- Barrett’s oesophagus, under specialist care.
- Zollinger-Ellison syndrome, a rare acid-overproduction condition.
- Preventing rebleeding after a bleeding ulcer, given intravenously in hospital.
Timing is the practical key, and it is the commonest thing people get wrong. Proton pumps are activated by eating, and esomeprazole only blocks pumps that are active. Take it about 30 minutes to an hour before your first meal of the day. Taken at bedtime or after food, a substantial part of the dose is wasted — and that is far and away the most frequent reason a PPI is reported not to work.
It is slow to start — one to four days to full effect — so it does nothing for heartburn happening right now. That is what an antacid or an alginate is for.
PPIs are among the most over-continued medicines in use. They are frequently started for a defined short-term reason and never stopped. If you have been on one for more than a few months without a review, that is worth raising.
How Nexium fits into this medicine category
| Group | Examples | Speed and strength |
|---|---|---|
| Proton pump inhibitors | Esomeprazole (Nexium), omeprazole, lansoprazole, pantoprazole | Days to full effect; strongest, longest |
| H2 blockers | Famotidine, cimetidine | About an hour; several hours |
| Antacids | Eno, aluminium and magnesium salts | Minutes; short-lived |
| Alginates | Gaviscon-type products | Minutes; raft that blocks reflux |
| Antispasmodics | Hyoscine (Hyospasmol) | Cramping, not acid |
| Prokinetics | Metoclopramide (Adco-Contromet) | Nausea and stomach emptying |
A PPI daily for control, with an antacid or alginate for breakthrough symptoms, is a sensible pairing. See the digestive and stomach medicines hub.
What to check before using Nexium
Tell your doctor or pharmacist if you:
- Take clopidogrel, used after heart attacks and stents. PPIs can reduce its effect; pantoprazole is often preferred in that situation.
- Take warfarin, methotrexate, digoxin, phenytoin, citalopram, ketoconazole or itraconazole, or HIV medicines.
- Take iron or vitamin B12 supplements — reduced acid lowers absorption of both.
- Have liver disease.
- Have osteoporosis or risk factors for it.
- Are due for an **endoscopy or an H. pylori test. PPIs can mask the symptoms of stomach cancer and cause false-negative H. pylori results**, so tell whoever arranges it — you may need to stop beforehand.
- Are pregnant or breastfeeding.
Practical points:
- Take it 30 to 60 minutes before your first meal.
- Swallow tablets or capsules whole; if swallowing is difficult, some forms can be dispersed — ask a pharmacist rather than crushing.
- Give it several days before judging it.
- Do not stop abruptly after long-term use. Acid can rebound above baseline for a week or two, producing heartburn that feels exactly like the original problem returning — and often prompts people to restart unnecessarily. Tapering avoids most of this.
- Review it periodically.
Possible cautions and when to ask a pharmacist or doctor
Common effects are headache, nausea, diarrhoea, constipation, wind and abdominal pain — usually mild.
Long-term use is associated with low magnesium, vitamin B12 deficiency, an increased risk of certain gut infections, and a small increase in fracture risk. These justify periodic review rather than stopping a medicine you need.
Get emergency help for:
- Vomiting blood, or material like coffee grounds.
- Black, tarry stools.
- Severe abdominal pain.
- Chest pain with breathlessness, sweating, or pain spreading to the arm or jaw. Heart attack pain is frequently mistaken for heartburn, and acid remedies are frequently taken instead of calling for help.
- Swelling of the face, lips or tongue, difficulty breathing, or a blistering rash.
Seek prompt advice for muscle cramps, tremor, palpitations or unusual weakness (possible low magnesium), severe or persistent diarrhoea, or joint pain with a rash in sun-exposed areas.
Contact your doctor if:
- Symptoms do not improve after two weeks, or return whenever you stop.
- You have difficulty or pain swallowing, or food sticking.
- You have unintentional weight loss, persistent vomiting, or loss of appetite.
- You are over 45 with new indigestion.
- You have been taking it more than a few months without review.
Those middle points are what separate ordinary reflux from something needing investigation — and a PPI that works just well enough is exactly how they get missed.
Related medicine guides
Frequently asked questions
What is Nexium 40 mg used for? Reflux and heartburn, erosive oesophagitis, stomach and duodenal ulcers, and as part of H. pylori treatment. It contains esomeprazole; 40 mg is the higher adult strength.
What is Nexium 20 mg used for? The same conditions at the standard adult dose, and for maintenance once symptoms are controlled.
Is Nexium available in South Africa? Not under that brand name in the medicine price register, but esomeprazole is registered here under other names including Nectizole and Nextell.
Is esomeprazole better than omeprazole? Only slightly, and mainly in severe oesophagitis. For everyday reflux the difference is marginal — a switch between them is not a downgrade.
When should I take it? 30 to 60 minutes before your first meal of the day. Taken after food or at night, much of the dose is wasted.
How quickly does it work? One to four days for full effect. Use an antacid or alginate for immediate relief.
Can I stop taking it? After long-term use, taper rather than stopping abruptly — acid can rebound and mimic the original problem.
Is it safe long term? Widely used long term where needed. Long-term use is linked to low magnesium, B12 deficiency and a small fracture risk, which is why review matters.