A minority of patients with hyperthyroidism resulting from relapsed Graves disease or autonomous nodules refuse definitive treatment with surgery or radioiodine, and request long-term anti-thyroid medication. There are few data concerning the safety and efficacy of this therapeutic modality.
We performed a retrospective analysis of 13 patients (8 relapsed Graves disease, 5 toxic MNG), 12F, median age 60 (3176) yrs and duration of long-term therapy 64.6 (45103) mths. All pts initially received CBZ, with 2 necessitating change to PTU as a consequence of side-effects. During long-term treatment a mean of 6.7+/−5.2 (1.24/yr) dose changes were made per patient with 33% representing an increase in dose. Overall weight increased 7.5+/−6.3 kg, with 1.3+/−3.6 kg acquired during the last two years on treatment. Six of 13 patients lost weight during the last two years of treatment. TFTs were assessed 3.3+/−1.6 times/yr during long-term therapy. Free T4 (fT4) decreased from a median of 63.7(31.9 to >100) to 14.7+/−2.6 pmol/L (68%), with 8.8% of the reduction occurring within the final two years treatment. The range of fT4 narrowed annually, with a decrease in variance of 38% from the mean on long-term treatment during the last two years of therapy. Conversely, the suppressed TSH rose to a median of 1.32 (<0.033.57) miu/L. Unlike fT4, increases in TSH were more uniform, with <0.01% of the overall change in TSH from diagnosis occurring during the final two years on treatment. An elevated ALP was observed in 70% of patients at diagnosis, and all normalised on long-term anti-thyroid therapy (mean decrease 154+/−136 IU/L). ALP rose in 2 patients (mean 17.5+/−0.14 IU/L), but remained within the normative range. The mean decrease in ALP during long-term therapy was −16.4 (38.2 to −77.5)%.
Following initial control of hyperthyroidism with anti-thyroid medication, continued long-term therapy is an effective and safe alternative to definitive treatment of refractory hyperthyroidism.