Clinical features and management of overdosage with thyroid drugs

Accidental ingestion and overdose of medications used in thyroidal illnesses may occur because of the frequency of these diagnoses. This review discusses acute overdosage of 4 groups of medicines. Acute ingestion of thyroid replacement medications occurs very frequently. Overdosage in children is usually asymptomatic and a benign condition; after evacuation of the stomach, propranolol may be used to treat symptomatic children. Other therapeutic regimens are rarely indicated in this age group. Ingestions of large amounts of antithyroid medications occur very rarely and limited information regarding treatment is available in the medical literature. Acute ingestion of iodine often results in corrosive injury of the gastrointestinal tract and renal damage. Cardiopulmonary collapse secondary to circulatory failure, oedema of the epiglottis and aspiration pneumonias may cause death. Administration of starch and sodium thiosulphate, maintenance of airway and stabilisation of circulation are the major components of therapy. Acute overdosage of beta-blockers is uncommon but can be lethal. Patients may appear well initially but they can suddenly develop convulsions and profound cardiovascular collapse requiring instant aggressive therapy. Potassium and glucose concentrations should be monitored. The usage of atropine, isoprenaline (isoproterenol), glucagon and prenalteral is discussed.