Along with their useful effects, most medicines can cause unwanted side effects although not everyone experiences them. The unwanted effects often improve as your body adjusts to the new medicine, but please speak with your doctor or pharmacist if they continue or become troublesome.

All medicines can cause allergic reactions although serious allergic reactions are very rare. Any sudden wheeziness, difficulty in breathing, swelling of the eyelids, face or lips, rash or itching (especially affecting your whole body) should be reported to a doctor immediately.

Acetazolamide can affect the cells in your blood. This could mean that you are more likely to catch infections and that your blood may not clot properly. If you have a sore throat or fever or you notice bruises or tiny red or purple spots on your skin, you should contact your doctor immediately. If your muscles feel weak or you have fits, you should see your doctor immediately.

Acetazolamide can affect the liver and kidneys. If you experience pain in your lower back, pain or burning when you pass urine, have difficulty in passing urine, or you stop passing urine, have blood in your urine, pale stools, or if your skin or eyes look slightly yellow, you should contact your doctor. You should also contact your doctor if your stools are black or tarry, or if you notice blood in your stools.

Below is a list of side effects associated with Acetazolamide. You will find a full list of possible side effects in the Patient Information Leaflet (PIL) supplied with your medicine.

• Headache
• Diarrhoea
• Feeling or being sick, loss of appetite, thirst, or a metallic taste in the mouth
• Dizziness, loss of full control of arms or legs
• Looking flushed
• A need to pass urine more often than normal
• Tiredness or irritability
• Feeling over-excited
• A tingling or numbness in the fingers or toes, or coldness in the extremities
• Depression
• Drowsiness or confusion
• A loss of interest in sex
• Ringing in the ears or difficulty in hearing
• Temporary short-sightedness which subsides when the dosage is reduced, or treatment is stopped

Rare cases of skin rashes including an increased sensitivity to sunlight have been reported. If you experience any unusual skin rashes, inform your doctor. Contact a doctor immediately if you experience a serious skin reaction; a red, scaly rash with bumps under the skin and blisters (exanthematous pustulosis).

If you take Acetazolamide for a long time it can occasionally affect the amount of potassium, or sodium in your blood. Your doctor should conduct blood tests to check that this does not happen. You might also experience bone thinning or kidney stones with long-term therapy. High or low blood sugar levels may occasionally occur.

If any side effects become serious, or if you notice any side effects not listed in the Patient Information leaflet (PIL), please tell your doctor or pharmacist.