Treatment with antithyroid drugs for thyrotoxicosis with hyperthyroidism can be initiated by the GP but may require secondary care input. The main medicines used are carbimazole (first choice) or propylthiouracil which inhibit thyroid peroxidase (TPO), a key enzyme involved in thyroid hormone synthesis.[^4,7]

As carbimazole is linked to congenital malformations, women of childbearing potential should be advised about MHRA guidance to use effective contraception. Carbimazole should also be stopped immediately if acute pancreatitis occurs.[^25,26]

Sometimes these antithyroid medicines can be given alternately with levothyroxine as a ‘block and replace’ therapy to finetune response.[²⁷]

Once a condition such as Graves’ disease or toxic nodular goitre has been confirmed, the patient may be offered radioactive iodine treatment, especially if drug treatment alone is not achieving remission or is contraindicated. Surgery to remove the thyroid gland, thyroidectomy is another possibility.[⁷]

Short term thyrotoxicosis without hyperthyroidism usually only needs supportive treatment such as betablockers for cardiovascular symptoms.[^7,14]