Remission of Grave's disease after oral anti-thyroid drug treatment

To evaluate remission rate of anti-thyroid drug treatment in patients with Grave's disease, and to study the factors associated with remission.

A cross sectional study.

The Endocrine Department of the Aga Khan University Hospital, Karachi from 1999 to 2000.

Seventy four patients of Grave's disease were recruited who were prescribed medical treatment. Grave's disease was diagnosed in the presence of clinical and biochemical hyperthyroidism along with anti-microsomal (AMA) and anti-thyroglobulin antibodies (ATA) and thyroid scan. These patients were prescribed oral anti-thyroid drugs using titration regime and followed at 3, 6, 12 and 18 months. Patients were categorized into two groups: "remission group" and "treatment failure group" and results were compared using a chi-square test, t-test and logistic regression model with significance at p < 0.05.

A majority of the patients were females (62.6%, n=46). During the follow-up period of 18 months, 41.9% patients went into remission. Univariate analysis showed that the initial free T4 level was significantly different (p < 0.05) in patients in remission and treatment failure groups. Multivariate analysis showed only initial free T4 level was a significant predictor of outcome. Positive AMA patients (n=27) had higher treatment failure (odds ratio: 2.55: 95%, CI 0.69 - 9:31), although the difference was not statistically significant (p = 0.13).

Remission rates with oral anti-thyroid agents is markedly high. Patients should be offered alternate treatment options to those who do not enter remission during a period of 12-18 months of treatment, those who develop relapse, and those who have aggressive disease on initial presentation.