Zanprol (Omeprazole)

How does it work?

Zanprol tablets contain the active ingredient omeprazole, which is a type of medicine called a proton pump inhibitor. Omeprazole is also available without a brand name, ie as the generic medicine.) Omeprazole acts in the stomach to decrease the production of stomach acid.

Proton pumps are found on cells that line the stomach and are used by these cells to produce stomach acid. Omeprazole works by inhibiting the action of the proton pumps, and this reduces the production of stomach acid.

Acid is produced in the stomach as a normal part of the digestive process. However, sometimes this acid can flow back into the food pipe (oesophagus). This is called gastro-oesophageal reflux, and can cause pain and a burning sensation known as heartburn.

Omeprazole reduces the production of stomach acid and therefore stops excess acid flowing back into the foodpipe. It can be bought without a prescription from pharmacies to relieve heartburn symptoms associated with acid reflux.

What is it used for?

  • Reflux symptoms, eg heartburn, in adults aged 18 years and over.

How do I take it?

  • Adults aged 18 years and over should take two Zanprol 10mg tablets once a day. The tablets should preferably be taken in the morning. You can take them either with or without food.
  • The tablets should be swallowed whole with half a glass of water. Do not chew or crush the tablets. If you have difficulty swallowing the tablets you can break them and disperse them in a spoonful of non-carbonated water, acidic fruit juice (eg apple, orange or pineapple) or apple sauce. This mixture should be taken within 30 minutes. Always stir the mixture before taking it (it won't be clear). The solid pieces contain the medicine - do not chew or crush them. To make sure you have taken all the medicine you should rinse the glass with water and drink it. Do not use fizzy water or milk to rinse the glass.
  • The medicine should start to provide relief from heartburn symptoms within a day or so of starting treatment, but it may take two to three days of treatment before your symptoms are fully relieved. Once your symptoms start to get better the dose should be reduced to one tablet once a day. Once your symptoms have gone away you should stop taking the medicine. You should not take this medicine to prevent heartburn or reflux.
  • If your heartburn is not relieved within two weeks of starting treatment with this medicine you should consult your doctor. Do not take this medicine continuously for more than four weeks without consulting your doctor again.
  • Do not exceed the recommended dose of this medicine.


  • You should consult your doctor before taking this medicine if any of the following apply to you:
    • you are aged 55 years or older and have new or recently changed indigestion or heartburn symptoms
    • you have needed to use heartburn or indigestion remedies continuously for four or more weeks to control your symptoms
    • you are due to have an endoscopy or urea breath test
    • you have lost weight unintentionally
    • you are anaemic
    • you have difficulty or pain swallowing
    • you have bleeding from your back passage (rectum)
    • you have persistent vomiting or vomiting blood
    • you have abdominal pain or swelling
    • you have previously had a peptic ulcer or surgery on your stomach or intestines
    • you have jaundice, liver problems or liver disease
    • you have any other significant medical condition.
  • If you have not experienced any relief from your symptoms after two weeks of treatment with this medicine you should consult your doctor for medical advice. You should also consult your doctor if you need to keep taking this medicine for four weeks or longer to control your symptoms.
  • Heartburn and indigestion can be symptoms of more serious conditions such as stomach ulcers and stomach cancer. For this reason, if you suffer from long-term, recurrent heartburn or indigestion symptoms, you should make sure you consult your doctor on a regular basis for check-ups, particularly if you are over 55 years of age and are taking medicines on a daily basis to relieve your symptoms.
  • As omeprazole decreases the acidity in the stomach, it may lead to a slightly increased risk of getting stomach infections such as Salmonella and Campylobacter.

Use with caution in

  • People with decreased liver function.

Not to be used in

  • Children and adolescents under 18 years of age.
  • Zanprol tablets contain lactose and are not suitable for people with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption.

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • If you are pregnant or breastfeeding you should seek medical advice from your doctor before using this medicine. However, omeprazole is not known to be harmful when used during pregnancy or breastfeeding.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

Common (affect between 1 in 10 and 1 in 100 people)

  • Headache.
  • Disturbances of the gut such as diarrhoea, constipation, nausea, vomiting, abdominal pain or wind (flatulence).

Uncommon (affect between 1 in 100 and 1 in 1000 people)

  • Dizziness or spinning sensation.
  • Sleepiness.
  • Difficulty sleeping (insomnia).
  • Pins and needles sensations (paraesthesia).
  • Increased liver enzymes.
  • Skin reactions such as rash, hives, itching or dermatitis.
  • Feeling generally unwell (malaise).
  • Swelling of the legs and ankles due to excess fluid retention (peripheral oedema).

Rare (affect between 1 in 1000 and 1 in 10,000 people)

  • Blurred vision.
  • Dry mouth.
  • Taste disturbances.
  • Inflammation of the mouth (stomatitis).
  • Thrush infection (candidiasis) in the stomach or intestines.
  • Pain in the muscles and joints.
  • Confusion.
  • Agitation.
  • Depression.
  • Hair loss.
  • Increased sweating.
  • Increased sensitivity of the skin to UV light (photosensitivity).
  • Decreased numbers of white blood cells or platelets in the blood (leucopenia or thrombocytopenia).
  • Decreased level of sodium in the blood (hyponatraemia).
  • Inflammation of the liver (hepatitis).
  • Jaundice.
  • Kidney inflammation (interstitial nephritis).

Very rare (affect less than 1 in 10,000 people)

  • Aggression.
  • Hallucinations.
  • Decreased level of magnesium in the blood (hypomagnesaemia).
  • Liver failure.
  • Muscle weakness.
  • Severe skin reactions.
  • Breast swelling in men.
  • Impotence.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

You should tell your pharmacist what medicines you are taking, including those bought without a prescription and herbal medicines, before you buy this medicine. This is so the pharmacist can make sure this medicine is safe and suitable for you to take. This is particularly important if you taking any of the medicines mentioned below, because you may need to see your doctor so your treatment can be monitored, or your medicine doses altered.

While taking this medicine you should not take any additional medicines to reduce stomach acid, for example H2 antagonists such as ranitidine or cimetidine, unless you are advised to by your doctor.

Omeprazole should not be taken by people taking the anti-HIV medicines atazanavir, nelfinavir or rilpivirine. This is because omeprazole decreases the blood level of these medicines and could make them less effective at treating HIV infection.

Omeprazole may increase the blood levels of the following medicines and may therefore increase the risk of their side effects:

  • benzodiazepines such as diazepam, triazolam, lorazepam or flurazepam
  • cilostazol (omeprazole should be avoided in people taking cilostazol)
  • citalopram
  • digoxin
  • escitalopram
  • methotrexate
  • phenytoin
  • raltegravir (omeprazole should be avoided in people taking raltegravir)
  • saquinavir (omeprazole should be avoided in people taking saquinavir)
  • tacrolimus.

Omeprazole may increase the anti-blood-clotting effect of the anticoagulant medicine warfarin. If you are taking warfarin it is recommended that your blood clotting time (INR) is checked after starting and stopping this medicine.

Due to its effect on the acidity in the stomach, omeprazole may reduce the absorption of the following medicines from the stomach, which could make them less effective:

  • erlotinib
  • itraconazole
  • ketoconazole
  • lapatinib
  • pazopanib
  • posaconazole
  • ulipristal
  • vandetanib.

The antidepressant fluvoxamine may increase the amount of omeprazole in the blood. You may need a lower than normal dose of omeprazole if you are taking this antidepressant and seem to be getting a lot of omeprazole side effects.

Voriconazole may increase the blood level of omeprazole and omeprazole may increase the blood level of voriconazole. Your doctor may need to adjust your doses of these medicines if you are having long-term treatment with both of these medicines, or if you have severe liver problems.

The anti-HIV medicine tipranavir may reduce the amount of omeprazole in the blood and could make it less effective.

Omeprazole is not recommended for people taking the antiplatelet medicine clopidogrel. This is because recent evidence has shown that omeprazole can make the clopidogrel less effective at preventing heart attacks and strokes. This medicine should only be used in combination with clopidogrel if your doctor feels it is essential.

Other medicines containing the same active ingredient

Losec Mepradec

Omeprazole capsules and tablets are also available without a brand name, ie as the generic medicine.