Plasma exchange aids thyroidectomy in refractory amiodarone-induced thyrotoxicosis, despite variable biochemical responses

Abstract

Introduction: Amiodarone-induced thyrotoxicosis (AIT) is a serious complication of amiodarone therapy, associated with high morbidity and mortality. Standard medical therapies are often insufficient in refractory cases, and therapeutic plasma exchange (TPE) has been proposed as a bridge to definitive thyroidectomy, although protocols for its use vary and detailed descriptions and definitions of response to therapy are limited. Case presentation: We report four cases of severe refractory AIT, prepared for thyroidectomy with TPE. Patients underwent three to five sessions using either albumin with saline, or combinations including fresh frozen plasma, as replacement fluids. TPE produced variable biochemical effects: free thyroxine (FT4) levels consistently fell during sessions but rarely normalised, while total thyroxine (TT4) normalised in some cases. In most patients, thyroid-stimulating hormone (TSH), previously suppressed for months, rose to detectable levels after only one to two sessions, suggesting a rapid reduction in biologically active thyroid hormone (TH) concentration. TPE was well tolerated overall, although transient coagulopathy and thrombocytopaenia occurred in two cases. All patients proceeded to successful thyroidectomy and achieved post-operative euthyroidism. Conclusion: TPE may provide temporary biochemical improvement and clinical stabilisation in refractory AIT, facilitating safe progression to thyroidectomy. However, its biochemical effects can be inconsistent and transient, and complications such as coagulopathy must be anticipated. Our experience supports the use of TPE as a valuable adjunct in selected patients with refractory AIT but illustrates that thyroidectomy should not be unnecessarily delayed in pursuit of complete TH normalisation or rigid biochemical targets.