title: Methyltestosterone-induced transient hyperthyroidism in a hypothyroid patient.
abstract: In this paper we report different effects of methyltestosterone administration on thyroid function in two twin brothers, one of whom suffered from hypothyroidism, while the other was apparently healthy. Methyltestosterone, which is a non-aromatisable androgen, resulted in a marked reduction of thyroxine-binding globulin (TBG), irrespectively of the patient's hormonal status, while the impact on free thyroid hormones depended on baseline thyroid function. Our research shows that a possibility of the use of non-aromatisable androgens or other drugs affecting TBG levels should be taken into consideration in all hypothyroid patients receiving levothyroxine, in whom thyroid hormone status suddenly changes without any apparent reason.
authors.affiliation: Department of Internal Medicine and Clinical Pharmacology, Medical University of Silesia, Katowice, Poland. r.krysiak@interia.pl
authors.forename: R
authors.initials: R
authors.lastname: Krysiak
authors.forename: B
authors.initials: B
authors.lastname: Okopien
mesh_terms: D000328:Adult; D045930:Anabolic Agents / Q000009:adverse effects*; D004200:Diseases in Twins / Q000188:drug therapy*; D020249:Hormone Replacement Therapy; D006801:Humans; D006980:Hyperthyroidism / Q000139:chemically induced*; D007037:Hypothyroidism / Q000188:drug therapy*; D008297:Male; D008777:Methyltestosterone / Q000009:adverse effects*; D013974:Thyroxine / Q000627:therapeutic use*; D056825:Thyroxine-Binding Globulin / Q000187:drug effects
chemical_list: D045930:Anabolic Agents; D056825:Thyroxine-Binding Globulin; D013974:Thyroxine; D008777:Methyltestosterone