title: Can quetiapine-induced hypothyroidism be reversible without quetiapine discontinuation?
abstract: Recent clinical trials and case reports have recorded dose-related thyroid function test abnormalities during quetiapine treatment usually requiring drug discontinuation or initiation of thyroid replacement therapy. The authors highlight the potential reversibility of quetiapine-induced hypothyroidism without quetiapine discontinuation in 2 in-patients (a 51-year-old schizophrenic woman and a 46-year-old bipolar man) to which quetiapine (300 and 350 mg/d, respectively) was administered. Both patients had a negative personal and family history of thyroid dysfunction. Significant decreases in T4/free T4 levels and a marked elevation in thyroid-stimulating hormone level were recorded without any clinical signs of hypothyroidism 3 weeks after quetiapine initiation. Antithyroid antibody titers remained within reference range. Thyroid function tests returned to normal 6 weeks after quetiapine initiation, although quetiapine was continued at the same daily dose without thyroid replacement therapy. These are the first cases reporting spontaneous resolution of quetiapine-induced hypothyroidism without quetiapine discontinuation. We suggest careful thyroid monitoring for patients initiating quetiapine. However, physicians can wait in cases of quetiapine-induced hypothyroidism if a close laboratory monitoring is available because thyroid dysregulation may soon resolve.
authors.affiliation: University of Athens, 1st Department of Psychiatry, Eginition Hospital, Athens, Greece. bkont@cc.uoa.gr
authors.forename: Vassilis P
authors.initials: VP
authors.lastname: Kontaxakis
authors.forename: Dimitris
authors.initials: D
authors.lastname: Karaiskos
authors.forename: Beata J
authors.initials: BJ
authors.lastname: Havaki-Kontaxaki
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Ferentinos
authors.forename: George N
authors.initials: GN
authors.lastname: Papadimitriou
mesh_terms: D003987:Dibenzothiazepines / Q000008:administration & dosage* / Q000009:adverse effects*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000139:chemically induced* / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D000069348:Quetiapine Fumarate
chemical_list: D003987:Dibenzothiazepines; D000069348:Quetiapine Fumarate