Omeprazole - Oral

Patient Medicine Information
Why do I need this medicine?
Omeprazole is a gastric medicine.

It is used to treat conditions caused by excessive acidity in your stomach, such as ulcers in the stomach or duodenum (upper portion of the small intestine), reflux disease (also known as "heartburn", in which food or acid from your stomach backs up into your mouth, leaving a sour or bitter taste) and hypersecretory conditions such as Zollinger-Ellison syndrome (a condition in which a growth in the pancreas or duodenum or both secretes too much acid).

This medicine can also be used to relieve stomach irritation and ulceration caused by certain painkillers such as non-steroidal anti-inflammatory drugs (NSAIDs).

Omeprazole treats these conditions by reducing the amount of acid your stomach makes.

This medicine may also be used together with other medicines to treat a specific type of stomach problems caused by the Helicobacter pylori bacteria.

Omeprazole may be used to treat other conditions as decided by your doctor.
How do I take this medicine?
Take Omeprazole exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

Ask your doctor or pharmacist about whether you should take Omeprazole with or without food. Different brands of Omeprazole may be taken differently. Try to take it at the same time each day.

Swallow the capsule or tablet whole; do not chew or crush the capsule or tablet. If you have trouble swallowing, check with your doctor or pharmacist on how you should take this medicine.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the dosage and course of your treatment depending on the condition.

You may need to take Omeprazole for some time before the full benefits can be felt. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
What should I do if I have forgotten to take this medicine?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.
When should I not use this medicine?
Do not take Omeprazole with nelfinavir (medicine for HIV infection).
What should I take note of while taking this medicine?
Inform your doctor if you have liver disease.

Do not take Omeprazole for a long period of time as it may slightly increase your risk of fracture in the hip, wrist or spine. Inform your doctor if you have osteoporosis (soft, brittle bones).

Let your doctor know if you are pregnant or breastfeeding.

Be sure to check with your doctor or pharmacist before giving this medicine to an elderly or children.

Inform your doctor if you get a rash on your skin, especially in areas exposed to the sun.

If your gastric problem seems to be getting worse, let your doctor know.

If you are going for certain laboratory tests (e.g. urea breath test, Chromogranin A), inform your doctor that you are taking this medicine.

Individuals who are ultrarapid metaboliser of CYP2C19 may respond poorer to this medicine and may require dose adjustment. Although not routinely done, your doctor may advise you to take genetic testing to check if this medicine is best suited for you. If you know you have this gene type, inform your doctor.

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly. You may need to have routine blood tests (magnesium level) to check your body’s response to the medicine. Your doctor will advise you about how often you need to have these tests.
What side effects could I experience?
Omeprazole may cause dizziness. If affected, do not drive or take part in any activity in which you need to be alert.

Other side effects include any of the following: headache, diarrhoea, constipation, stomach pain, nausea, vomiting and wind in the stomach.

Some side effects may be serious, although they are not common. Alert your doctor quickly if you experience:
  • rashes with skin peeling or blisters
  • severe stomach pain or cramps, loose, watery or bloody stools, or severe diarrhoea
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I take this with other medicines?
Do not take Omeprazole with cilostazol (medicines used to treat cramping muscle pain or numbness in the extremities), nelfinavir or atazanavir (medicine for HIV infection).

Inform your doctor and pharmacist if you are taking any of these medicines:
  • medicines for HIV infection e.g. saquinavir, ritonavir
  • blood-thinning medicines e.g. warfarin, clopidogrel
  • medicines for fungal infection e.g. ketoconazole, itraconazole, voriconazole
  • medicines used in organ transplant or certain immune disorders e.g. ciclosporin, tacrolimus
  • medicines for sleep disorder or anxiety e.g. diazepam
  • digoxin (medicine for heart disease)
  • methotrexate (anticancer medicine)
  • phenytoin (medicine for epilepsy or fits)
This list does not include all medicines that may interact with Omeprazole.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicine, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
It may be helpful to discuss your diet with your doctor or dietitian. A change in diet may help improve your symptoms. For example, spicy food tends to worsen reflux and should be avoided. Likewise, carbonated ("fizzy") drinks such as soft drinks should also be avoided.

You should also try to avoid lying down soon after eating as this will worsen the reflux symptoms.

Avoid alcohol.
How should I store this medicine?
Store in a cool, dry place away from the reach of children.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on Omeprazole - Oral and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by
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