If you notice any of the following serious side effects, stop taking Nexium and contact a doctor immediately:

• Yellow skin, dark urine and tiredness which can be symptoms of liver problems. These effects are rare, and may affect up to 1 in 1,000 people.
• Sudden wheezing, swelling of your lips, tongue and throat or body, rash, fainting or difficulties in swallowing (severe allergic reaction). These effects are rare, and may affect up to 1 in 1,000 people.
• Sudden onset of a severe rash or reddening of the skin with blisters or peeling may occur even after several weeks of treatment. There may also be severe blisters and bleeding in the lips, eyes, mouth, nose and genitals. The skin rashes may develop into serious widespread skin damage (peeling of the epidermis and superficial mucous membranes) with life threatening consequences. This could be ‘erythema multiforme’, ‘Stevens-Johnson syndrome’, ‘toxic epidermal necrolysis’ or ‘drug reaction with eosinophilia and systemic symptoms’. These effects are very rare, and might affect up to 1 in 10,000 people.

Other side effects include:

Common (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).
• Injection site reaction.
• Benign polyps in the stomach.

Uncommon (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).
• Eyesight problems such as blurred vision.
• Dry mouth.
• Changes in blood tests that check how the liver is working.
• Skin rash, lumpy rash (hives) and itchy skin.
• Fracture of the hip, wrist or spine (if Nexium is used in high doses and over long duration).

Rare (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.
• Low levels of sodium in the blood. This may cause weakness, being sick (vomiting) and cramps.
• Feeling agitated, confused or depressed.
• Taste changes.
• Suddenly feeling wheezy or short of breath (bronchospasm).
• 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).
• Generally feeling unwell and lacking energy.
• Increased sweating.

Very rare (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, drug reaction with eosinophilia and systemic symptoms).
• Muscle weakness.
• Severe kidney problems.
• Enlarged breasts in men.

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

• If you are on Nexium 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.
• Inflammation in the gut (leading to diarrhoea).
• Rash, possibly with pain in the joints.

Nexium 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 medication at this time.

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.