Acute thyroxine overdosage: two cases of parasuicide.

Factitious hyperthyroidism is a well documented clinical entity where the signs and symptoms of hyperthyroidism are self-induced by the chronic ingestion of excessive amounts of thyroxine l 2. The acute ingestion of large amounts of thyroxine might be thought to carry a risk of acute thyrotoxicosis, but despite high plasma levels of thyroxine this may not be so. Previous reports suggest that such cases are largely asymptomatic 3, but the majority of these have been in children 4-7. There are few guidelines available for the specific management of acute thyroxine overdose in adults, where the amount ingested is usually relatively larger and treatment is more likely to be delayed. Two cases are presented where large amounts of thyroxine were taken in attempted suicide.