Correspondence (letter to the editor): Target Range Was Missed

As an addendum to the article, which details the use of hormone replacement therapy after thyroid surgery, we wish to emphasize the importance of continuous therapeutic monitoring. As a target range for L-thyroxine substitution, a TSH serum concentration of 1–2 mU/L was recommended. Studies from the US (1) and the UK (2) give rise to the suspicion that a substantial proportion of patients receiving drug treatment for thyroid disorders are not adequately monitored in terms of their metabolic function. The results of one of our own studies from Germany (3), based on data from the population-based Study of Health in Pomerania (SHIP) showed that of 266 participants who took thyroid medication, 31% had TSH serum concentrations outside the local, study specific reference range and therefore missed the target range mentioned above.

In addition to unsatisfactory patient compliance, inappropriate dosage adjustment will result in mistreatment of thyroid disorders, which may be accompanied by adverse effects and constitutes a crucial reason for poor therapeutic results. We therefore recommend establishing therapeutic target ranges and placing more importance on monitoring drug treatment.