Neo-Mercazole 5mg Tablets

Carbimazole is used to treat an overactive thyroid gland (hyperthyroidism). It works by reducing the amount of thyroid hormone the gland produces.

It starts working straight away, but it may take 1 to 3 weeks to feel better and 1 to 2 months to work fully. Treatment often lasts 12 to 18 months, although some people need it for longer.

Take it exactly as your doctor or pharmacist tells you.

• You can take it with or without food. Swallow the tablets whole with a drink of water.
• If you miss a dose, take it as soon as you remember. If your next dose is due, take both together.
• You will need regular blood tests so your doctor can keep you on the lowest dose that works.
• Do not stop taking it without speaking to your doctor, as your thyroid levels may rise again.

Common side effects, usually in the first 8 weeks, include:

• feeling or being sick, headache, dizziness
• painful joints
• an itchy or mild rash
• hair thinning

Stop taking it and contact a doctor straight away if you have:

• a sore throat, mouth ulcers, high temperature, flu-like symptoms, severe tiredness, or easy bruising or bleeding (signs of a low white blood cell count)
• yellow skin or eyes, or dark urine
• sudden severe tummy pain
• swollen glands, muscle pain or weakness, or less urine or blood in your urine
• swelling of the face, lips or throat, or trouble breathing

Check with your doctor or pharmacist before taking it if you:

• have had an allergic reaction to carbimazole or propylthiouracil
• have had pancreatitis after taking carbimazole before
• have liver problems, a blood disorder or an enlarged thyroid (goitre)
• are having radioactive iodine treatment
• cannot have regular blood tests
• are pregnant, trying to conceive or breastfeeding
• take digoxin, warfarin, theophylline, erythromycin, beta-blockers, steroids such as prednisolone, clozapine, or biotin supplements

Store as directed on the pack or leaflet, and keep out of the reach of children. Ask your pharmacist if you are unsure.

Infection risk: rarely, carbimazole lowers white blood cells. Tell your doctor at once if you get a sore throat or fever.

Pregnancy: use reliable contraception. It is not often recommended in pregnancy; if you become pregnant, keep taking it and contact your doctor promptly.

Breastfeeding: it is usually fine if your baby is healthy, but get advice.

Driving and alcohol: if it makes you dizzy, avoid driving and alcohol until you feel normal.