Clenbuterol ingestion causing prolonged tachycardia, hypokalemia, and hypophosphatemia with confirmation by quantitative levels

Background: Clenbuterol is a long acting beta-adrenergic agonist used in th e treatment of pulmonary disorders. Acute clenbuterol toxicity resembles th at of other beta(2)-adrenergic agonists. Most previously reported cases of clenbuterol toxicity describe patients who ate livestock illicitly treated with clenbuterol. Case Report: We report a case of human clenbuterol toxici ty confirmed and correlated with qualitative and quantitative serum clenbut erol assays. This poisoned patient, a 28-year-old woman, developed sustaine d sinus tachycardia at 140/min, hypokalemia (2.4 mEq/L, 2.4 mmol/L), hypoph osphatemia (0.9 mg/dL, 0.29 mmol/L), and hypomagnesemia (1.52 mg/dL, 0.76 m mol/L) after ingesting a reportedly small quantity of clenbuterol. The pati ent received repeated doses of metoprolol to treat her cardiovascular stimu lation and potassium chloride to treat her hypokalemia. She remained sympto matic for more than 20 hours after the ingestion. Analysis by enzyme-linked immunosorbent assay and liquid chromatography/mass spectrometry revealed a serum clenbuterol concentration of 2.93 mcg/L 3 hours after the ingestion and an undetectable serum concentration 20 hours after ingestion. It is not eworthy that at a serum concentration below the limit of detection by liqui d chromatography/mass spectrometry, the patient remained symptomatic. Acute clenbuterol toxicity is rarely reported following illicit use in humans, a nd this is the first such case to provide confirmatory toxicological analys is.