Authors: F Bogazzi L Bartalena L Tomisti E Dell’Unto C Cosci C Sardella M L Tanda A Lai M Gasperi F AghiniLombardi E Martino
Publish Date: 2014/03/27
Volume: 31, Issue: 6, Pages: 515-519
Abstract
Context Amiodaroneinduced hypothyroidism AIH may occur in patients with or without underlying thyroid disorders In the latter restoration of euthyroidism after amiodarone discontinuation can be facilitated and accelerated by a short course of potassium perchlorate KClO4 However it is unknown whether KClO4 may exert similar effects on thyroid function of AIH patients if amiodarone treatment is continued Objective To evaluate the effects of KClO4 on thyroid function in AIH patients without underlying thyroid disease while continuing amiodarone treatment Design and patients An open prospective study of 10 consecutive AIH patients without underlying thyroid abnormalities referred to a tertiary referral center and treated with KClO4 600 mg/day for a period of 26±13 days range 15–45 days An additional historical group of 12 consecutive patients with subclinical AIH left untreated while continuing or after withdrawing amiodarone was retrospectively evaluated as to the outcome of thyroid function Measurement Serum free T4 free T3 and TSH concentrations were measured at booking during KClO4 treatment and after withdrawing the drug Results In the prospective study KClO4 treatment restored euthyroidism in all patients within 28±11 days range 15–45 days After KClO4 with drawal however all patients became hypothyroid again after 45±15 days range 30–60 days Two patients developed mild leukopenia 1 case or a slight increase in serum creatinine levels 1 case which promptly normalized after KClO4 withdrawal In the historical group followed for at least 12 months euthyroidism was spontaneously and stably achieved after an average of 6 months in 5 patients in whom amiodarone could be discontinued while subclinical hypothyroidism persisted in 7 patients in whom amiodarone had to be continued Conclusions KClO4 very effectively restores normal thyroid function in AIH patients without underlying thyroid abnormalities despite the fact that amiodarone therapy is continued However euthyroidism does not persist after KClO4 is withdrawn in addition spontaneous recovery of euthyroidism does not seem to occur in this subset of AIH patients unless amiodarone is discontinued Therefore also in view of its potential sideeffects KClO4 cannot be recommended as a firstline treatment for AIH if amiodarone needs to be continued while LT4 replacement is recommended under these circumstances with periodical reassessment of thyroid function
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