Omeprazole Side Effects

Home › Medicine Side Effects › omeprazole

Answer the side-effect intent for omeprazole without diagnosing; distinguish common from serious reactions and give safe next-step/reporting guidance.

What is omeprazole?

Omeprazole contains the active ingredient OMEPRAZOLE.

• Active ingredient — OMEPRAZOLE
• Registration number — 34/11.4.3/0297
• Registration holder — Dr ReddyÕs Laboratories (Pty) Ltd

It is approved for:

• OMEPRAZOLE DRL 20 belongs to a group of medicines called “proton pump inhibitors”
• OMEPRAZOLE DRL 20 works by reducing the amount of acid that your stomach produces
• OMEPRAZOLE DRL 20 is used for the temporary, short-term relief of heartburn and high stomach acid levels in adults

Common side effects of omeprazole

Not everyone gets side effects. The effects below are those listed in the South African approved leaflet, grouped using the leaflet’s own frequency wording.

Frequent side effects

• Headache (If the headache is severe, it may be necessary to stop treatment with OMEPRAZOLE DRL 20)
• Effects on your stomach or gut: Diarrhoea (If the diarrhoea is severe, it may be necessary to stop treatment with OMEPRAZOLE DRL 20, constipation, abdominal pain or colic, wind (flatulence), non-cancerous (benign) abnormal tissue growth (polyps) in the stomach
• Feeling sick (nausea) or being sick (vomiting)

Less frequent side effects

• Blood problems such as a reduced number of white blood cells or platelets. This can cause weakness, bruising or make infections more likely. Changes in blood count include agranulocytosis (lack of white blood cells)
• Suddenly feeling wheezy or short of breath (bronchospasm)
• Severe kidney problems (interstitial nephritis)
• Changes in blood tests that check how the liver is working; liver inflammation (hepatitis), which may include jaundice which can cause yellow skin, dark urine and tiredness; liver failure leading to brain damage
• Low levels of sodium in the blood. This may cause weakness, being sick (vomiting) and cramps
• Sudden onset of a severe rash or blistering or peeling skin. This may be associated with a high fever and joint pains (Erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis)
• Seeing, feeling or hearing things that are not there (hallucinations)
• Feeling agitated, confused or depressed
• Aggressiveness
• Trouble sleeping (insomnia)
• Dizziness
• Feeling sleepy
• Tingling feelings such as “pins and needles”
• Blurred vision
• Swelling of the ankles, feet or hands
• Dry mouth
• An inflammation on the inside of the mouth
• Thrush in the gullet
• Taste changes
• Skin rash, itchy skin, lumpy rash (hives), skin sensitivity to light
• Hair loss
• Muscle or joint pain
• Lack of energy, generally feeling unwell
• Enlarged breasts in men Frequency of side effect not known:
• Inflammation in the gut (leading to diarrhoea) If any of these side effects get serious, or

Serious side effects and warning signs

This leaflet does not set out a separate list of serious side effects. The general warning signs below apply to any medicine.

General warning signs that apply to any medicine

How long can side effects last?

How long a side effect lasts depends on the effect, the product, how long it has been used, and the person. Some effects ease within days as the body adjusts. Others continue for as long as the product is used. A few can persist after stopping, and some need review rather than waiting.

• Settling effects — mild effects that ease over the first days or weeks of use
• Ongoing effects — effects that continue while the product is being used and improve after stopping
• Persistent effects — effects that continue after stopping and need medical review
• Delayed effects — effects that appear after weeks or months rather than immediately

Which of these applies to a particular effect is a clinical question. If a side effect is not settling, is getting worse, or is affecting your daily life, that is worth a conversation with a pharmacist or doctor regardless of how long it has been going on.

Factors that may affect side effects

The approved leaflet identifies the following cautions and factors.

Do not use it at all if

• if you are hypersensitive (allergic) to omeprazole or any of the other ingredients of OMEPRAZOLE DRL 20 (listed under Section 6)
• if you are pregnant or breastfeeding
• if you are taking medicines called nelfinavir and atazanavir

Use with care, and tell your doctor, if

• You lose a lot of weight for no reason and have problems swallowing
• You get stomach pain or indigestion
• You begin to vomit food or blood
• You pass black, tarry stools (blood-stained faeces)
• You experience severe or persistent diarrhoea, as OMEPRAZOLE DRL 20 has been associated with an increased risk of infectious diarrhoea
• You have kidney problems OMEPRAZOLE DRL 20 can cause a type of kidney problem (acute tubulointerstitial nephritis). Some people who take proton pump inhibitor (PPI) medicines, including OMEPRAZOLE DRL 20, may develop a kidney problem called acute tubulointerstitial nephritis that can happen at any time during treatment with OMEPRAZOLE DRL 20. Call your doctor right away if you have a decrease in the amount that you urinate or if you have blood in your urine
• You have liver problems, therefore your doctor may want to reduce your dose
• You are taking a medicine called atazanavir (
• You have a problem with Vitamin B12 levels in your body
• You are taking a medicine called clopidogrel
• You suffer from a condition called osteoporosis (weak bones which are easily broken) or if you are taking medicines called corticosteroids
• You suffer from tiredness, dizziness, fits and heart problems or if your magnesium levels are low
• You are taking a medicine called digoxin or other medicines that decrease your magnesium levels
• You get a rash or skin reaction, especially after being exposed to the sun, after treatment with
• You are due to have a specific blood test (Chromogranin A)
• You start suffering from stomach infections and runny tummy (diarrhoea) Use in children There is only a small amount of experience with the use of OMEPRAZOLE DRL 20 in children

Pregnancy and breastfeeding

• Do not take OMEPRAZOLE DRL 20 capsules if you are pregnant or breastfeeding
• If you are pregnant or breastfeeding, think you may be pregnant or are planning to have a baby, please consult your doctor, pharmacist or other health care provider for advice before receiving this medicine

Interactions and medicines to check

The approved leaflet names these interactions.

• Clopidogrel (used to treat blood clots) – Taking OMEPRAZOLE DRL 20 capsules together with clopidogrel or 12 hours apart results in a lower concentration of clopidogrel in the blood and increases the risk of blood clotting
• Diazepam (used to treat anxiety, relax muscles or in epilepsy)
• Warfarin (used to thin the blood) – Your doctor may need to take regular blood tests to check how well your blood can clot
• Phenytoin (used to treat epilepsy) – Your doctor may need to take blood tests to check your phenytoin blood levels
• Digoxin (used to treat heart problems)
• Nelfinavir and atazanavir (used to treat HIV infection)
• Tacrolimus (used to prevent rejection of transplanted organs)
• Methotrexate (used to treat certain types of cancer or to control severe psoriasis or rheumatoid arthritis)
• Ketoconazole, itraconazole, posaconazole or voriconazole (used to treat infections caused by a fungus)
• Erlotinib (used to treat cancer) If you are using any of these medicines, you may not be able to take OMEPRAZOLE DRL 20, or you may need dosage adjustments or your doctor may need to monitor you carefully for side effects. OMEPRAZOLE DRL 20 with food and drink You can take OMEPRAZOLE DRL 20 capsules with food or on an empty stomach. Swallow the capsules whole with a half glass of liquid

What to do if you experience side effects

If you think you are having a side effect, the response depends on how severe it is. Use the warning signs above first — if any of those apply, treat it as urgent.

If the symptom is severe or frightening

Get medical help immediately. Call 10177 for an ambulance, or 112 from a mobile phone, or go to the nearest emergency department. Take the product and its packaging with you if you can.

If the symptom is mild but bothering you

• Write down what the symptom is, when it started, and how it relates to when you take the product
• Check the leaflet that came with the product to see whether the symptom is listed
• Speak to your pharmacist — for many questions this is the fastest route to a useful answer
• Contact the prescriber if the symptom is affecting your daily life or is not settling

You can also report a suspected side effect in South Africa. Reporting does not replace getting medical advice, and you do not need to be certain the product was the cause.

When to seek urgent medical help

Some symptoms need medical attention straight away rather than an appointment in a few days. Do not wait to see whether they settle.

Get same-day medical advice if you have

• A high fever, or a rash together with feeling generally unwell
• Yellowing of the eyes or skin, or unusually dark urine
• Unusual bruising or bleeding that you cannot explain
• Severe or persistent vomiting or diarrhoea, especially if you cannot keep fluids down
• A sudden change in mood, or thoughts of harming yourself
• Any symptom that is rapidly getting worse

How to report a suspected side effect in South Africa

South Africa has an official system for reporting suspected side effects, run by the South African Health Products Regulatory Authority (SAHPRA). Reports from the public and from healthcare professionals are how safety signals get detected after a product is already in use.

Who can report

Anyone can report — you do not have to be a healthcare professional, and you do not need to prove that the product caused the problem. A suspicion is enough. Patients, caregivers and family members can all submit a report.

What to have ready

• The name of the product, its strength and form, and the batch number if you have it
• Why it was being used, and when it was started and stopped
• What the suspected reaction was, when it began, and how long it lasted
• Any other medicines, supplements or remedies being used at the same time
• Basic details about the person affected — age and sex are usually enough

How to report

SAHPRA accepts adverse reaction reports through its e-Services reporting system and through the Med Safety mobile app. Healthcare professionals can also report through the same routes. Current forms and access points are published on the SAHPRA site.

• SAHPRA Health Products Vigilance — the main vigilance and reporting hub
• SAHPRA e-Services — current adverse reaction reporting access

For a fuller walkthrough see how to report an adverse drug reaction.

Related pages

• minoxidil side effects

← Back to more medicine side effects.