Like all medicines, Naproxen tablets can cause side effects, although not everybody gets them. If any of the side effects get worse, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.
Tell your doctor if you notice any of the following side effects
Very common (affects more than 1 user in 10) feeling sick, constipation.
Common (affects 1 to 10 users in 100) confusion, headache, ringing in the ears, changes in vision (you should go for an eye test if you notice changes in vision), tiredness, drowsiness, dizziness, rashes, heart failure, diarrhoea, being sick, water retention (may cause swelling in the limbs).
Uncommon (affects 1 to 10 users in 1,000) depression, irregular heartbeat (palpitations), abnormal dreams, forgetfulness, difficulty concentrating, sensitivity of the skin to light (may cause blistering), difficulty sleeping.
Rare (affects 1 to 10 users in 10,000) high blood potassium levels (causing irregular, slow heart beat, feeling sick), hair loss, jaundice (yellow skin or eyes), hearing difficulties, inflammation of blood vessels (causing fever, swelling and general unwellness), worsening of asthma, muscle weakness/pain, ulcers on the inner cheeks, gums and tongue, hepatitis - sometimes fatal (symptoms include feeling tired, loss of appetite, feeling or being sick and pale coloured stools).
Very rare (affects less than 1 user in 10,000) changes in the numbers and types of blood cells (if you develop sore throats, nose bleeds or infections consult your doctor), anaemia (may cause fainting, chest pain, breathlessness), fits, aseptic meningitis (may cause fever, feeling or being sick, disorientation, headache, neck stiffness and sensitivity to light), severe skin rash with flushing, blisters or ulcers (Stevens- Johnson syndrome), blisters or sores on the skin, kidney damage or infection (may cause blood in the urine, decrease in amount of urine passed, feeling or being sick), inflammation of the pancreas; pancreatitis (causing fever, stomach pain, sickness). Medicines such as naproxen may be associated with a small increased risk of heart attack (myocardial infarction) or stroke.
Not Known (frequency cannot be estimated from the available data) low amounts of white cells in the blood (may cause fever or frequent infections), runny nose, lowered female fertility (see section 2), sensing things that are not there, high blood creatinine levels seen in blood tests, kidney failure, kidney disease (may cause changes in the need to or amount of urine), thirst, fever, inflammation in the eye (causing eye pain or changes in vision), tingling or “pins and needles”, a spinning sensation, high blood pressure, abnormal liver function seen in tests, wind, worsening of colitis and Crohn’s disease, worsening of Parkinson’s disease, general feeling of discomfort and illness, swelling of the hands and feet, swelling in the eye (causing headaches or blurred vision).
If any of the side effects get worse, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.