Pharmacokinetic evaluation of a case of massive sotalol intoxication

OBJECTIVE: To describe serum concentrations and clearance of sotalol after a massive overdose. CASE SUMMARY: A 37-year-old white man took 11.2 g of sotalol hydrochloride tablets in a suicide attempt. The first serum d,l-sotalol concentration 3 hours after taking the first tablet was 20.6 mg/L and the last measured concentration 59 hours later was 1.8 mg/L. Logarithmic transformation of the concentration data indicated two separate monoexponential phases in the elimination curve, with half-lives of 30.1 and 11.6 hours. DISCUSSION: The shorter serum half-life in the later phase is comparable with that in four previously reported sotalol intoxications and within the normal range. The elimination rate increased in a temporal manner with an increase in systolic blood pressure about 30 hours after the patient was admitted. Since the sotalol elimination rate depends principally on renal function, we believe the initially slow elimination is due to a temporary reduction of the renal function caused by the systolic hypotension. CONCLUSIONS: An initial phase of slow sotalol elimination may occur after severe overdoses. In our patient this was probably due to hypotension. Thus, blood pressure should be monitored carefully.