Carbimazole reduces how much thyroid hormone the gland produces. It is the standard first treatment for an overactive thyroid, and it usually takes four to eight weeks before symptoms such as palpitations, tremor and weight loss settle.

What Carbimazole Is Used For

Overactive thyroid, including Graves disease
Preparing a patient before thyroid surgery or radioiodine
Long term control of thyroid hormone levels

Common Side Effects

Itching and skin rash
Joint aches
Nausea
Altered taste

Precautions

The important warning is about the blood cells. If you develop a sore throat, mouth ulcers, fever or feel suddenly unwell, stop the tablets and get an urgent blood count, because a rare drop in white cells can occur. Thyroid function is checked regularly and the dose adjusted. Tell your doctor if you are pregnant or planning to be, as treatment needs specialist adjustment.

This page is general information only. It is not a substitute for advice from your doctor or pharmacist, and it does not include dosage. Always follow the directions given to you and read the leaflet inside the pack.