Prednisolone Dosing Regimen for Treatment of Subacute Thyroiditis.

The rate of recurrence of subacute thyroiditis (SAT) during prednisolone (PSL) therapy is approximately 10 to 20%. However, there is little or no information on the time period to relapse following administration of a tapered dose of PSL and the factors associated with such relapse. The aim of this study was to determine the correlation between SAT recurrence and PSL tapering regimen used in the treatment of SAT. This study was a medical record-based retrospective study and involved 26 patients (3 men, 23 women) who received PSL therapy for SAT. The primary endpoint was the association between recurrence and number of days required to taper daily PSL dose to 5 mg. The secondary endpoint was the relationship between recurrence and several variables including age, clinical score, free thyroxine, inflammatory reaction, thyroglobulin, total treatment time, total dose of PSL and presence or absence of creeping thyroiditis. The SAT recurrence rate was 15.3%. There was no significant difference in the initial PSL dose between the non-recurrence and recurrence groups (27.5 mg vs 24.5 mg, P = 0.302). However, for the primary endpoint, significant differences were found between the two groups in time required for tapering PSL to 5 mg/day (non-recurrence: 44.3 ± 15.3 days, recurrence: 19.0 ± 11.9 days, P = 0.012). None of the clinical variables evaluated correlated significantly with SAT relapse. In conclusion, to prevent recurrence of SAT, consideration should be given to the period required for PSL tapering to 5 mg/day.