Antithyroid drugs in Graves' disease: Are we stretching it too far?

Early and durable achievement of euthyroid or hypothyroid status with low likelihood of relapse is the key to effective treatment of Graves' disease (GD). Although antithyroid drugs (ATDs) are commonly used first-line agents, likelihood of remission remains highest with radioactive iodine (RAI) therapy and surgery. Data regarding efficacy and economical superiority of RAI therapy over ATDs are lacking from India. This study was designed to study the response to long-term (>12 months) use of ATDs in GD with respect to attainment of remission and to compare the cost of treatment with ATDs versus RAI therapy beyond 12 months.

The study was conducted in a tertiary care center.

This was a retrospective analysis.

Patients of GD in our follow-up from February 2009 to March 2016 who had received ATDs for a duration exceeding 12 months were retrospectively analyzed. Patients who underwent radioablation after a period of at least 12 months on ATDs were analyzed and their status was recorded after a minimum of 6 months after radioablation. Patients who remained hyperthyroid beyond 12 months and received RAI therapy were further compared with those who continued on ATDs, for achievement of euthyroid or hypothyroid status. Cost analysis was done for follow-ups and treatment and compared.

All analyses were done using Fisher's exact test for categorical and descriptive statistics for numerical data.

Use of ATDs leading to euthyroid and hypothyroid status in GD patients was only significant beyond 24 years when compared to those at <12-18 months therapy (P = 0.0262 and P = 0.0217, respectively). The patients who ended up with hypothyroid status were significantly greater in RAI group compared to ATD group (P = 0.0003). Cost of therapy per patient beyond 12 months was lower in the RAI group compared to the ATD group (cost difference Rs. 5435.00).

Within limitations, our study demonstrates that RAI is effective and economical option in GD.