Life-threatening hyponatremia due to cessation of L-thyroxine.
Electrolyte disorders in hypothyroidism are frequently subtle and rarely observed in clinical practice. A 50-year-old woman was admitted to the emergency room with complaints of nausea, weakness, and lethargy. Her medical history revealed total thyroidectomy two years earlier. She was commenced on L-thyroxine after the surgery. However, the patient stopped the treatment for three months. Thyroid function tests showed free T3 0.80 pg/ml (n: 1.8-4.2), free T4 <0.20 ng/dl (n: 0.8-1.9), TSH 56.84 microU/ml (n: 0.4-4.0). Her biochemical and laboratory investigations were normal, except for a plasma sodium value of 114 mmol/L (n: 135-145). Hypertonic saline treatment with L-thyroxine was immediately started. Symptomatic hyponatremia caused by hypothyroidism was the direct consequence of cessation of L-thyroxine treatment. The patient was followed up for a year and still using L-thyroxine (0.1 mg). In conclusion, it should be kept in mind that life-threatening hyponatremia may occur in patients with total thyroidectomy-induced hypothyroidism; L-thyroxine should be immediately started if stopped for any reason.
Sari
Ramazan
R
Akdeniz University, School of Medicine, Department of Internal Medicine, Division of Endocrinology, Antalya, TR-07070, Turkey.
Sevinc
Alper
A
D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000209:etiology* / Q000503:physiopathology; D007037:Hypothyroidism / Q000150:complications* / Q000188:drug therapy; D008875:Middle Aged; D012462:Saline Solution, Hypertonic / Q000627:therapeutic use; D013974:Thyroxine / Q000008:administration & dosage / Q000627:therapeutic use*
D012462:Saline Solution, Hypertonic; D013974:Thyroxine