Recent trends in the management of Graves' hyperthyroidism in Japan: opinion survey results, especially on the combination therapy of antithyroid drug and thyroid hormone

Abstract

An opinion survey concerning the management of Graves' hyperthyroidism was conducted among the council members of the Japan Thyroid Association. The selection of 3 major treatments by 90 respondents for their patients was 98.6 +/- 4.2% for antithyroid drug (ATD), 7.8 +/- 12.6% for partial thyroidectomy and 5.2 +/- 8.1% for radioiodide. They expressed a movement away from the past trend of surgery because of postoperative complications and unsatisfactory therapeutic results, and they assumed a further reduction in the future. On the other hand, the frequency of radioiodide treatment was not considered to have decreased greatly, and they expected a slight increase in the future. Of the respondents, 65% suggested that hyperthyroidism should be completely cured even if the patient would fall into hypothyroidism. The major reasons for choosing surgery or radioiodide after ATD were the adverse effects of ATD and the age and social backgrounds of the patients. Large goiter size was the 3rd reason for surgery but was a minimal indicator for radioiodide. As for ATD treatment, none of the respondents reported the routine application of any uniform fixed-time therapy protocol. Japanese Graves' patients were shown to be less responsive to ATD than Caucasian patients. This was assumed to result at least from high iodide intake, and half of them had ordered their patients to restrict iodide intake. Furthermore, 78% of them had treated with a combined therapy of ATD and thyroid hormone. Most of them apply this for selected patients mainly to lower TSH receptor antibody activity, to better control their patients and to reduce the goiter size. All but 8 (9%) did not give T4 (or T3) after the cessation of ATD, and they felt this to be unnecessary, doubtful about the effect, unsuitable or even possible to induce recurrence. The excellent findings reported by Hashizume et al. (N Engl J Med 324: 947-953, 1991) are well known among them. However, most of them did not agree with the efficacy of the protocol to reduce TRAb or to improve the remission rate, and 90% of the respondents did not intend to apply the protocol immediately. In conclusion, the Japanese thyroidologists were shown to highly prefer ATD, and they intended to treat their patients for longer periods of time only by ATD until clinical remission is achieved. The combination therapy is widely used, but most of them do not consider it effective. The therapeutic protocol reported by Hashizume et al. was not accepted widely in Japan.