Side Effects of Carbimazole

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Carbimazole, a drug which is considered a "pro-drug" because it converts to Methimazole after entering the body, is used to treat individuals with an overactive thyroid gland. Users of this drug have a reported a number of mild to severe side effects.


Carbimazole is a prescription drug which is is often sold under the brand name Tapazole. It is considered an antithyroid agent because it blocks production of the thyroid hormone to reduce its output to more normal levels. reports that it "... is used to treat hyperthyroidism (overactive thyroid). It is also used before thyroid surgery or radioactive iodine treatment." Other uses of Carbimazole may be determined by your doctor.

Common Side Effects

Common side effects which have been reported by users of Carbimazole include dizziness, drowsiness, headache, pain in the joints, nausea, vomiting, upset stomach, muscle pain, taste changes and numbness. Though less serious than other side effects, contact your doctor if any of these side effects become more bothersome or regularly occur.

Severe Side Effects

According to, In rare cases, the following severe side effects may occur as a result of using Carbimazole: yellowing of the skin or eyes, fever, chills, persistent sore throat, tremors, stomach pain, severe headache, easy bruising or bleeding, hair loss and vision changes. Consult a full list of side effects before using Carbimazole. If any of the above side effects occur, seek immediate medical attention.


In the event of an overdose, seek immediate medical attention. Symptoms of overdose can include chest pain, joint pain, nausea, headache, swelling and vomiting. Strictly adhere to your particular prescription to avoid the occurrence of overdose. Never take a double dose of Carbimazole to compensate for a missed dose.

Safety Information

The use of alcohol may cause the side effects of drowsiness and dizziness to become more severe. The use of Carbimazole can cause harm to an unborn foetus. Contact your doctor if you are pregnant or planning on pregnancy. Consult a full list of possible drug interactions before regularly using Carbimazole.