Treatment of thyrotoxicosis —the current position

Summary

Clinical thyrotoxicosis is due to an excess of thyroxine (T4) or triiodothyronine (T3) in blood and tissues. Graves' disease, with goitre and exophthalmos, is the commonest by far in the U.K. but other entities such as thyrotoxicosis occurring in a patient with a long-standing nodular goitre, with a solitary adenoma, with a visceral neoplasm, or with acromegaly should not be forgotten. A patient may take too much prescribed thyroid hormone. Congenital or neonatal thyrotoxicosis is a variant of Graves' disease. Recently, thyrotoxicosis apparently due exclusively to too much T3 production has been described.

The role, if any, of the immunoglobulin LATS in the aetiology of thyrotoxicosis is discussed but, like the ubiquitous effects of stable iodine in and on the thyroid, its discovery has added little to management. Patients aged 40 years or more are given radioactive iodine therapy unless they are pregnant, or likely to be, and provided they do not have large nodular and unsightly goitres producing mechanical or cosmetic disability. Certainly the old and the frail, those with other diseases such as rheumatic heart disease and diabetes should receive radioactive iodine therapy; this is also the best treatment for younger patients who refuse or are unfit for operation or who have antithyroid drug sensitivity or relapse after thyroidectomy.

Antithyroid drugs, and the safest seems to be carbimazole, are given to all other patients. Those with severe thyrotoxicosis, a large goitre and fluctuating control should have a partial thyroidectomy carried out by an experienced surgeon, when everybody is adjusted to the idea. Other patients, and these include young people in general, pregnant patients and those with a small thyroid, should be given carbimazole for up to 18 months (long-term antithyroid drug therapy). Relapse after drug treatment can be treated by another course of drugs, an operation (after initial drug control) or radioactive iodine therapy, the choice depending on a number of factors including age, fertility and acceptability.

Key Words::

• Hyperthyroidism
• drug therapy
• radiotherapy
• thyroidectomy