Severe envenoming by the Indian red scorpion Mesobuthus tamulus: the use of prazosin therapy.

We describe the clinical course and outcome in 46 victims of severe scorpion envenoming treated with prazosin (P), and compare them with earlier patients treated with conventional therapy (C) (n = 45) and nifepidine (N) (n = 28). The incidence of complicating left ventricular failure was 29% for C, 35% for N and 6.5% for P; that of acute pulmonary oedema was 46% for C, 14% for N and zero for P; mortality was 25% for C, 3.5% for N and zero for P. Although this is a historical study, prazosin appears to significantly reduce morbidity and shorten recovery time. Experience in other countries suggests that antivenom is helpful in controlling many of these problems, but in rural India serotherapy remains largely unavailable, and prazosin is a mainstay of treatment.