Other Brands/Names

Neo Mercazole.

How It Works

Carbimazole is a medication used to manage thyroid overactivity. It functions by decreasing the production of the hormone thyroxine in the thyroid gland.

Indications

Carbimazole is prescribed for treating hyperthyroidism, a condition in which the thyroid gland becomes overactive and produces excessive thyroid hormones. This can lead to symptoms like irregular heartbeat, hand tremors, excessive sweating, and sudden weight loss. The thyroid is a butterfly-shaped gland located at the front of the neck, responsible for releasing hormones that help regulate how the body uses energy, a process known as metabolism. Carbimazole may also be used to reduce symptoms of hyperthyroidism before undergoing treatment with radioactive iodine or thyroid surgery.

Contraindication

• Known allergy to carbimazole

• Severe blood-related conditions

• History of acute pancreatitis (inflammation of the pancreas)

• Serious liver impairment

Side Effects

• Abdominal discomfort

• Nausea or vomiting

• Mild rash or itching of the skin

• Inform your doctor promptly if the following serious side effects occur:

  • Muscle or joint aches

  • Tingling or numbness of the skin

  • Difficulty breathing or coughing up blood

  • Liver-related symptoms (persistent nausea or vomiting, yellowing of the skin or eyes, dark-colored urine, severe abdominal pain)

  • Kidney-related symptoms (changes in urination, blood in urine)

• Although uncommon, a severe allergic reaction may occur. Seek immediate medical care if you notice any of the following: skin rash, facial or throat swelling, intense dizziness, or difficulty breathing.

Types

Carbimazole is offered in tablet form, each containing 5 mg of the active ingredient.

Dosage

• Adults: The starting dose is 15–60 mg per day, divided into 2–3 doses, and is gradually reduced once thyroid hormone levels stabilize (euthyroidism). Maintenance treatment typically ranges from 5–15 mg per day, and may be taken as a single dose. The treatment period usually lasts between 6 and 18 months.

• Children aged 3–17 years old: Begin with 15 mg daily, with adjustments made based on the patient's response.

Safety

• Carbimazole should not be taken during the first trimester of pregnancy. Your healthcare provider may recommend an alternative medication during this stage. During the final two trimesters, carbimazole may be used only when clearly necessary, and the benefits and risks should be thoroughly discussed with your doctor.
• This drug can pass into breast milk. Speak to your doctor before starting breastfeeding.

Drug Interactions

• May enhance the effect and side effects of blood-thinning medications (anticoagulants)

• May increase the concentration of theophylline (used for breathing conditions such as asthma), raising the risk of toxicity

• May reduce the effectiveness of prednisolone (a corticosteroid)

• May raise the likelihood of side effects from erythromycin (an antibiotic)

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