Graves’ hyperthyroidism: Is it better to start with lower-dose therapy?

If lower doses of drugs for Graves' hyperthyroidism are used, adverse effects are lower too.

Graves' disease is a common cause of hyperthyroidism or 'overactive thyroid'. This is a condition that affects 2 out of every 1,000 men (0.2%) and 20 out of every 1,000 women (2%). This often leads to a visible enlargement of the thyroid gland. This swelling in the neck is called a goitre.

More serious though are the internal consequences of an over-function of the thyroid. If the thyroid is producing too much of particular types of hormones, it can cause an increase in the metabolic rate, rapid heart rate and nervousness.

The cause of Graves' hyperthyroidism is an error of the body's own immune system. It develops antibodies that allow the thyroid to grow and produce too many hormones. The overproduction of hormones can be treated with anti-thyroid medications.

Using these drugs, though, is something of a balancing act. If the dose is too low, the recurrences will be more common. If the dose is too high, adverse effects are a problem. Relatively common among these are allergic skin reactions (rashes), and rarely, a reduction in particular defensive cells of the immune system. This makes the person vulnerable to infections. With this in mind, researchers have looked for a way to find the best dose for each patient.

A systematic analysis of the available trials published by researchers from the Cochrane Collaboration describes the progress made in this search.

The analysis showed that two particular variations of treatments for Graves' hyperthyroidism have been the most tested. One of the strategies was to start with a relatively high dose. The alternative involved starting off with a lower dose that was then increased over the following weeks.

The trials showed that the slower increase in medication dosage was accompanied by fewer adverse effects. Out of 100 people who used this treatment, 9 stopped taking the medication (9%). About 5 in 100 developed a skin reaction (5%). In comparison: out of 100 people who started with the high dose, 16 stopped taking the medication (16%) and 10 out of 100 had a skin reaction (10%).

There is still not enough evidence to know though, whether one of these two types of treatment result in more recurrences. In general, it seems as though recurrences might be less likely if treatment continues for 12 to 18 months rather than a short course of six months.