[Toxicity of sulpiride]

Sulpiride is a benzamide neuroleptic used in the treatment of some psychiatric and gastroenterological disorders. Its antipsychotic, antiautistic, activizing and antidepressive properties result from antagonistic action to dopaminergic D2, D3 and D4 receptors in the central nervous system (CNS). The oral bioavailability of sulpiride is poor and it does not appear to have an extensive first-pass metabolism, nor is it extensively protein-bound. Elimination of sulpiride appears to depend primarily on the kidneys. The acute sulpiride poisoning includes mainly neuropsychiatric (i.e., agitation, hallucinations, and CNS depression) as well as cardiac effects (i.e., hypotension, dysrhythmias, and sinus tachycardia). The life-threatening conditions with sometimes fatal outcome after sulpiride poisoning are prolongation of QTc interval with consequent torsade de pointes (TdP) and neuroleptic malignant syndrome (NMS). The quantitative methods for the measurement of sulpiride blood concentration are not routinely available and the toxic blood concentration is probably higher than 2 mg/L. Treatment of acute sulpiride poisoning includes standard protocols of gastrointestinal decontamination and further symptomatic and supportive measures, among them TdP (magnesium sulphate, isoproterenol, electrotherapy) and NMS treatment (benzodiazepines, bromocriptine, dantrolene, physical cooling).