Liothyronine abuse

Abstract

A 25-year-old man developed thyrotoxicosis due to abuse of liothyronine as part of recreational bodybuilding activities. The man presented to the emergency room due to headache, sweating and feeling generally unwell. Vital signs were as follows: body temperature 37.2°C, BP 148/73, RR 25, HR 123 and oxygen saturations 97% on room air. An insect bite on his arm was noted during an examination. The differential diagnosis of systemic inflammatory response syndrome following infected insect bite was considered.The man was treated with unspecified antibacterials and IV fluids in the ambulatory unit. He was referred to the acute medical team due to persistent malaise and tachycardia. ECG revealed sinus tachycardia. Initial laboratory tests revealed low levels of TSH and free thyroxine while elevate levels of urea, WBC count and neutrophil count. Haemoglobin, electrolytes, liver function tests and clotting screen were normal or closed to normal range. Subsequent endocrine investigations showed elevated levels of testosterone, prolactin and free T3 with borderline positive TSH receptor antibody while low levels of follicle stimulating hormone. Based on the laboratory findings, the differential diagnoses of systemic inflammatory response syndrome, sepsis, phaeochromocytoma and secondary hypothyroidism were excluded, and liothyronine-induced thyrotoxicosis was considered. He started receiving propylthiouracil and propranolol for thyrotoxicosis. Further endocrine screening was completed after a discharge on the same day from the ambulatory unit. At follow-up visit (2 weeks later), examination showed increased muscle bulk and well virilisation with normal secondary sexual characteristics. He had no evidence of thyroid eye disease or thyroid goitre. During anamnesis, he confessed that he had been self-administering injections of testosterone 375mg every week for 14 weeks in cycles and tablets containing liothyronine [triiodothyronine] 25µg daily for 4 weeks for recreational bodybuilding activities. He was advised about the potential harms of supplementation containing liothyronine and testosterone and recommended to stopped all the supplements containing exogenous hormone. Propylthiouracil was discontinued as intrinsic thyroid disease was excluded. At follow-up visit 8 months later, he felt well with normal thyroid functions.