Therapeutic Class

Antithyroid Agents


It is used for the treatment of thyrotoxicosis, Grave's disease and in the preparation of subtotal thyroidectomy

Chemical Composition

Each tablet contains Carbimazole 5mg


10 x 10's / Box

Dosage & Administration

To be administered orally. Thyrotoxicosis: Initially, a higher dose should be given to quickly render the patient euthyroid, and then gradually reduced to a minimum effective dose for maintenance. Suggested dosage for adults: Initial dose : 10 to 60mg daily in divided doses. Doses may be given at eight hour intervals. Maintenance : 5 to 20mg daily. Suggested dosage for children: 1 to 6 years : 7.5mg daily in divided doses as initial dose. above 6 years : 15mg daily in divided doses as initial dose. Preparation of thyrotoxic patient for surgery: Camazol should be given in sufficient dosage to render the patient euthyroid, and continued up to the time of operation. lodine should be prescribed together during the last two weeks. Dosages should be adjusted by the physician according to the response of the patient.


Contraindicated in patients with blood dyscrasias and those who have shown hypersensitivity towards carbimazole. Do not administer in patients with tracheal obstruction as high dosage may lead to thyroid enlargement and aggravate the condition.

Warning & Precautions

Although there is a risk to the foetus in pregnancy especially in high doses, it may be given with the smallest effective dose and given close medical supervision. Where possible, discontinue treatment 3 to 4 weeks before delivery. Carbimazole may be transferred to breast milk and if possible avoid breast feeding. However, if neonatal development is closely monitored, breast feeding may be carried out. It is dangerous to exceed the stated dose. Carbimazole may cause white cell disorders such as neutropenia and agranulocytosis, which may be fatal if treatment with carbimazole is not stopped promptly.These reactions usually occur during the first 3 months of therapy, and in most cases, are reversible on stopping treatment. Since agranulocytosis can develop very rapidly, periodic leukocyte counts alone may not be effective in the early detection of these reactions. During treatment with Camazol: 1. The patient should be asked to immediately report signs and symptoms suggestive of infection, e.g. sore throat, fever, mouth ulcer. 2. A white cell count should be performed if there is any clinical evidence of infection. 3. The drug should be stopped promptly if there is clinical or laboratory evidence of neutropenia. Following the onset of any signs and symptoms of hepatic disorder (pain in the upper abdomen, anorexia, general pruritus) in patients, the drug should be stopped and liver function tests performed immediately. Early withdrawal of the drug will increase the chance of complete recovery. Carbimazole tablets should be used with caution in patients with mild-moderate hepatic insufficiency. If abnormal liver function is discovered, the treatment should be stopped. The half-life may be prolonged due to the liver disorder.

Side Effects

Common side effects which usually occur in the first 8 weeks of treatment may include skin rashes, nausea, headache and gastrointestinal upsets. Other adverse effects sometimes observed include fever, arthralgia, myopathy, myalgia, a lupus-like syndrome, vasculitis and nephritis, taste disturbances, abnormal hair loss, pruritus and urticaria. Hepatic disorders, including abnormal liver function tests,hepatitis, cholestatic hepatitis, cholestatic jaundice dnd most commonly jaundice, have been reported; in these cases carbimazole tablets should be withdrawn. Rare cases of pancytopenia I aplastic anaemia and isolated thrombocytopenia have also been reported.Very rare cases of haemolytic anaemia have been reported. Patients must be advised to report incidence of sore throat immediately as agranulocytosis may be encountered. Over-treatment may lead to hypothyroidism and should be avoided in pregnancy as this may cause foetal goitre.

Drug Interaction

Drug interaction is not likely to occur with the use of Camazol.