Omez 20: Uses, How It Works, Side Effects
Also known as: Omez, Omez 20 mg, Omez-20, Omez 20 capsule, Omez20
Omez 20 is a gastro-resistant capsule containing 20 mg of omeprazole, a proton pump inhibitor (PPI). It lowers the amount of acid the stomach makes. It is used to treat and relieve acid reflux (GERD), heartburn and acidity, to help stomach and duodenal ulcers heal, and, together with antibiotics, to treat H. pylori infection. It is a prescription medicine.
- Active ingredient
- Omeprazole 20 mg
- Type of medicine
- Proton pump inhibitors (PPIs)
- Starts working in
- Acid falls within hours; symptoms often ease in a few days
- Effect lasts
- About 24 hours per dose
- With or without food
- Usually before breakfast
- Alcohol
- Best avoided; it can make acidity worse
- Pregnancy
- Ask your doctor
- Habit-forming
- No
- Made by
- Dr. Reddy's Laboratories Ltd
Pharmacist review in progress. This page is based on the sources listed below and is being checked by our registered pharmacist.
On this page
What is Omez 20 used for?
Omez 20 is used to lower stomach acid in conditions where acid causes symptoms or damage.
- Acid reflux, heartburn and acidity (gastro-oesophageal reflux disease, GERD)
- Inflammation or damage of the food pipe caused by acid (reflux oesophagitis), and helping to keep it from coming back
- Stomach (gastric) ulcers and duodenal ulcers
- Helicobacter pylori (H. pylori) infection, together with antibiotics
- Zollinger-Ellison syndrome and other rare conditions in which the stomach makes far too much acid
How does Omez 20 work?
The stomach lining contains cells that make acid using tiny 'proton pumps' (an enzyme called H+/K+ ATPase). Omeprazole is switched on by the acid inside these cells, then attaches firmly to the pumps so they stop pushing acid into the stomach. The body has to make new pumps to restore acid production, so one dose keeps acid low for about a day, even though the medicine itself leaves the blood within a few hours.
What happens in your body after you take it
You swallow the capsule
Omeprazole is broken down by acid, so the capsule holds tiny coated pellets that do not dissolve in the stomach. The capsule should be swallowed whole, not opened, chewed or crushed.
Absorbed in the small intestine
In the less acidic small intestine the coating dissolves and omeprazole is absorbed into the blood. Levels in the blood peak within a few hours of the dose.
It gathers in the acid-making cells
The blood carries omeprazole to the cells in the stomach lining that make acid. These cells have tiny, very acidic channels where the proton pumps sit, and omeprazole collects there.
Acid switches it on
In that acid, omeprazole changes into its active form, which binds to the proton pumps and switches them off. It only blocks pumps that are working. Eating turns pumps on, which is why the capsule is usually taken before breakfast.
Stomach acid goes down
Each blocked pump can no longer push acid into the stomach. With a dose each day, more pumps are blocked and acid falls further, which is why relief often builds over a few days.
The liver clears the medicine
The liver breaks omeprazole down using enzymes (mainly CYP2C19 and CYP3A4). This is why it can change how some other medicines are cleared. The break-down products leave mostly in the urine.
New pumps are made
The stomach keeps making new proton pumps, so acid production slowly returns. That is why one dose works for about a day and is usually taken once a day. After the last dose, acid levels return to normal over several days.
How to take Omez 20
Take Omez 20 exactly as your doctor advises or as printed on the pack. The dose and how long you take it depend on the condition being treated.
- It is usually taken once a day, before breakfast. Some conditions need it twice a day; follow your prescription.
- Swallow the capsule whole with water. Do not crush or chew it, because the coating protects the medicine from stomach acid.
- If you cannot swallow capsules, ask your pharmacist or doctor about other forms rather than opening it yourself.
- If you miss a dose, take it when you remember. If it is almost time for the next dose, skip the missed one. Do not take two doses together.
- Take it for as long as your doctor advises. Long-term use should be reviewed by a doctor regularly. Do not keep taking it for months on your own.
- Any use in children is decided by a doctor, who sets the dose by weight.
Side effects of Omez 20
Most people take omeprazole without problems, and side effects are usually mild. A few rare risks are linked mainly to using it for a year or more.
Uncommon or mild
- Headache
- Stomach pain
- Feeling sick (nausea) or being sick (vomiting)
- Constipation or diarrhoea
- Wind (gas)
- Dizziness
Rare but serious: get medical help
- Signs of a severe allergic reaction: swelling of the face, lips or throat, difficulty breathing, or a sudden widespread rash
- A serious skin reaction: red skin with blisters or peeling, sores in the mouth, or a widespread rash with fever. Get medical help immediately
- Watery or bloody diarrhoea that does not go away, with stomach cramps or fever, which can be a sign of a gut infection called C. difficile
- Passing less urine, blood in the urine, fever, rash or pain in the lower back, which can be signs of kidney inflammation
- A rash on skin exposed to the sun, especially with joint pain, which can be a sign of a lupus-type reaction
- Very low vitamin B12 (tiredness, tingling, a sore tongue) or weak bones, mainly after long-term use
- Muscle cramps or twitching, shaking, an irregular heartbeat or confusion, which can be signs of low magnesium, mainly after several months of use
Who should be careful
Omeprazole can ease symptoms that come from a more serious problem, and it can cause problems when taken for a long time. Some people need a doctor's check first.
When the label says not to use it
- Allergy to omeprazole, other proton pump inhibitors (substituted benzimidazoles) or any ingredient of the capsule
- Treatment with the HIV medicine rilpivirine, unless your doctor advises otherwise
- Warning signs that need a doctor's check first: unexplained weight loss, difficulty or pain when swallowing, repeated vomiting, vomiting blood, or black stools. Omeprazole can ease symptoms and hide a more serious problem such as stomach cancer
- Long-term use (especially a year or more): it can lower vitamin B12, weaken bones and slightly raise the risk of fractures and gut infections. Your doctor may review whether you still need it
- If you bought omeprazole without a prescription, do not take it for longer than 2 weeks without seeing a doctor
- Low magnesium, or taking water tablets (diuretics) or digoxin: your doctor may check magnesium levels
- Weak bones (osteoporosis), kidney disease or liver disease: tell your doctor first
- A planned endoscopy or tests for neuroendocrine tumours (chromogranin A): omeprazole may need to be paused for some time beforehand, so tell the doctor doing the test
- Pregnancy or breastfeeding: omeprazole is often considered usable, but ask your doctor or pharmacist first
- Past allergic reaction to omeprazole or similar medicines such as pantoprazole, esomeprazole or rabeprazole
Medicines and things that interact with Omez 20
Omeprazole lowers stomach acid and is broken down by liver enzymes, so it can change how some medicines work. Tell your doctor or pharmacist about everything you take.
- Clopidogrel (a blood thinner used after heart attacks or stents): omeprazole can make it less effective, so your doctor may choose a different acid-lowering medicine
- Warfarin and similar blood thinners: clotting tests (INR) may be needed more often
- Phenytoin and diazepam: omeprazole can slow their clearance, so their effect may be stronger
- Digoxin, tacrolimus and methotrexate: levels can rise, so your doctor may check them
- HIV medicines atazanavir, nelfinavir and rilpivirine: omeprazole can sharply lower their levels. Your doctor will decide if the combination is acceptable
- Medicines that need stomach acid to be absorbed, such as ketoconazole, itraconazole and iron tablets: they may work less well
- Voriconazole: it can raise omeprazole levels
- St John's wort and rifampicin: they may lower omeprazole levels
- Other acid-lowering medicines such as lansoprazole or famotidine: ask your doctor before combining
Effects on lab tests
- Chromogranin A blood test (used to look for neuroendocrine tumours): levels can rise and give a false positive
- Tests such as endoscopy: omeprazole may need to be paused beforehand, as your doctor advises
If someone takes too much
Taking one extra capsule by mistake is unlikely to cause harm. If someone has taken much more than prescribed, or feels unwell, call 112 or go to the nearest hospital and take the medicine pack with you.
Storage
Store in a cool, dry place in the original strip, protected from light and moisture, and out of the reach of children. Check the storage line on the pack. Do not use after the expiry date.
Regulatory status in India
Approved for sale in India. Single-ingredient omeprazole is not on the CDSCO list of banned medicines. Some fixed-dose combinations that include omeprazole are prohibited, for example omeprazole with paracetamol and diclofenac (section 26A), so check the ingredient list on the pack. Omez 20 contains omeprazole only.
Other brands with the same medicine
Many other brands and generic capsules contain omeprazole 20 mg and work the same way. Check the label for the strength. Combination products that add other ingredients are different medicines.
Other strengths and forms
Omeprazole is sold as capsules in 10 mg, 20 mg and 40 mg strengths and in some other forms by different companies. The strength is printed on the pack, so check the label of the one you have.
Common questions
When should I take Omez 20?
It is usually taken once a day before breakfast, swallowed whole with water. Omeprazole blocks acid pumps that switch on when you eat, so having it before the meal helps it work. Follow your doctor's advice or the label.
How long does Omez 20 take to work?
Acid output starts falling within hours of the first dose, but symptoms usually ease over a few days. It is not meant for instant relief of a sudden attack of acidity. Your doctor will say how long to take it.
Is Omez 20 an antacid?
No. Antacids neutralise acid already in the stomach and work within minutes for a short time. Omez 20 reduces how much acid the stomach makes, so it works more slowly but lasts about a day. Ask a pharmacist if you want to use both.
Can I take Omez 20 every day for a long time?
Only if your doctor advises it and reviews it regularly. Long-term use, especially beyond a year, is linked to low vitamin B12, weaker bones and gut infections. Many people need it only for a few weeks. Ask your doctor before continuing for months.
Can I open the Omez 20 capsule?
No, swallow it whole. The coated pellets inside protect omeprazole from stomach acid. If you have trouble swallowing capsules, ask your doctor or pharmacist about another form instead of opening it yourself.
What is the difference between Omez 20 and pantoprazole (Pan 40)?
Both are proton pump inhibitors that lower stomach acid in a similar way, but they are different molecules with different strengths and interactions. Which one suits you is for your doctor to decide, especially if you take other medicines.
Does omeprazole interact with other medicines?
Yes. It can affect clopidogrel, warfarin, phenytoin, digoxin, methotrexate and some HIV medicines, and it can reduce absorption of iron and some antifungals. Tell your doctor or pharmacist about everything you take, including herbal remedies.
Can I drink alcohol while taking Omez 20?
Alcohol does not change how omeprazole works, but it makes the stomach produce more acid and can worsen reflux and acidity. Tea, coffee, and spicy, fatty or acidic food can also trigger symptoms in some people.
Can I take Omez 20 in pregnancy or while breastfeeding?
Omeprazole can often be taken, but you should check with your doctor or pharmacist first. Do not start or stop it during pregnancy or breastfeeding without your doctor's advice.
Sources
- Omeprazole: a medicine to lower stomach acid. NHS (UK)
- Heartburn and acid reflux. NHS (UK)
- Omeprazole delayed-release capsules: prescribing information (label revised 8/2009, repackager copy). DailyMed, US National Library of Medicine
- PROTONIX (pantoprazole sodium) delayed-release tablets: full prescribing information (revised 6/2023). Pfizer (Wyeth Pharmaceuticals), US FDA-approved labeling
- Omeprazole. StatPearls, NCBI, US National Library of Medicine
- National Formulary of India. Indian Pharmacopoeia Commission
- List of drugs prohibited for manufacture and sale through gazette notifications under section 26A of the Drugs & Cosmetics Act 1940. Central Drugs Standard Control Organisation (CDSCO)
- National List of Essential Medicines 2022. Ministry of Health and Family Welfare, Government of India (copy hosted by CDSCO)