Light symptoms following a high-dose intentional L-thyroxine ingestion treated with cholestyramine

Adult exposure to L-thyroxine has a wide range of presentations: most adults either do not develop symptoms or only become minimally symptomatic. Appropriate treatments after exposure to L-thyroxine have yet to be established. A 26-year-old woman with a suicidal intention was witnessed to ingest approximately 50 L-thyroxine tablets, each containing 0.1 mg L-thyroxine (total dose 5 mg). Cholestyramine was administered (4 g every 8 h p.o.). Vital signs were monitored every 6 h and the hormone levels (L-thyroxine and thyroid-stimulating hormone) every 24 h. The thyroxine levels increased, and the thyroid-stimulating hormone levels decreased, with a normalization of the L-thyroxine level on postingestion day 6. Hypertension, dysrhythmias, and delusions did not appear in our patient. Only distal tremor and diaphoresis appeared on day 1 after ingestion. Cholestyramine has been used in cases of iatrogenic hyperthyroidism, in patients with Graves' disease, and in patients with digoxin intoxications, with good responses in all cases and a low incidence of side effects. This case illustrates the potential utility of cholestyramine to treat L-thyroxine intoxications.