Like all medicines, this medicine can cause side effects, although not everybody gets them. If you notice any of the following rare but serious side effects, stop taking Reprazol and contact a doctor immediately:
Sudden wheezing, swelling of your lips, tongue and throat or body, rash, fainting or difficulties in swallowing (severe allergic reaction). Reddening of the skin with blisters or peeling. There may also be severe blisters and bleeding in the lips, eyes, mouth, nose and genitals. This could be ‘Stevens-Johnson syndrome’ or ‘toxic epidermal necrolysis’. Yellow skin, dark urine and tiredness which can be symptoms of liver problems.

Common side effects (may affect up to 1 in 10 people)

• Headache.

• Effects on your stomach or gut: diarrhoea, stomach pain, constipation, wind (flatulence). Feeling sick (nausea) or being sick (vomiting).

Uncommon side effects (may affect up to 1 in 100 people)

• Swelling of the feet and ankles.

• Disturbed sleep (insomnia).

• Dizziness, tingling feelings such as “pins and needles”, feeling sleepy.

• Spinning feeling (vertigo).

• Changes in blood tests that check how the liver is working.

• Skin rash, lumpy rash (hives) and itchy skin.

• Generally feeling unwell and lacking energy.

Rare side effects (may affect up to 1 in 1,000 people)

• Blood problems such as a reduced number of white cells or platelets. This can cause weakness, bruising or make infections more likely.

• Allergic reactions, sometimes very severe, including swelling of the lips, tongue and throat, fever, wheezing.

• Low levels of sodium in the blood. This may cause weakness, being sick (vomiting) and cramps.

• Feeling agitated, confused or depressed.

• Taste changes.

• Eyesight problems such as blurred vision.

• Suddenly feeling wheezy or short of breath (bronchospasm).

• Dry mouth. An inflammation of the inside of the mouth.

• An infection called “thrush” which can affect the gut and is caused by a fungus.

• Liver problems, including jaundice which can cause yellow skin, dark urine, and tiredness.

• Hair loss (alopecia) Skin rash on exposure to sunshine.

• Joint pains (arthralgia) or muscle pains (myalgia).

• Severe kidney problems (interstitial nephritis).

• Increased sweating.

Very rare side effects (may affect up to 1 in 10,000 people)

• Changes in blood count including agranulocytosis (lack of white blood cells).

• Aggression.

• Seeing, feeling or hearing things that are not there (hallucinations).

• Severe liver problems leading to liver failure and inflammation of the brain.

• 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).

• Muscle weakness.

• Enlarged breasts in men.

Not known (frequency cannot be estimated from the available data)

Inflammation in the gut (leading to diarrhoea). If you are on Reprazol for more than three months it is possible that the levels of magnesium in your blood may fall. Low levels of magnesium can be seen as fatigue, involuntary muscle contractions, disorientation, convulsions, dizziness or increased heart rate. If you get any of these symptoms, please tell your doctor promptly. Low levels of magnesium can also lead to a reduction in potassium or calcium levels in the blood. Your doctor may decide to perform regular blood tests to monitor your levels of magnesium. Rash, possibly with pain in the joints.

Reprazol may in very rare cases affect the white blood cells leading to immune deficiency. If you have an infection with symptoms such as fever with a severely reduced general condition or fever with symptoms of a local infection such as pain in the neck, throat or mouth or difficulties in urinating, you must consult your doctor as soon as possible so that a lack of white blood cells (agranulocytosis) can be ruled out by a blood test. It is important for you to give information about your medicine at this time.

Reprazol may hide the symptoms of other diseases.

Therefore, if any of the following happen to you before you start taking Reprazol or while you are taking it, talk to your doctor straight away:

• 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 stools (blood-stained faeces). You experience severe or persistent diarrhoea, as omeprazole has been associated with a small increase in infectious diarrhoea.

• You have severe liver problems.

• You have ever had a skin reaction after treatment with a medicine similar to Reprazol that reduces stomach acid.

• If you take Reprazol on a long-term basis (longer than 1 year) your doctor will probably keep you under regular surveillance.
  You should report any new and exceptional symptoms and circumstances whenever you see your doctor. Taking a proton pump inhibitor like Reprazol, especially over a period of more than one year, may slightly increase your risk of fracture in the hip, wrist or spine. Tell your doctor if you have osteoporosis or if you are taking corticosteroids (which can increase the risk of osteoporosis).

• If you get a rash on your skin, especially in areas exposed to the sun tell your doctor as soon as you can, as you may need to stop your treatment with Reprazol. Remember to also mention any other ill-effects like pain in your joints.