OBJECTIVE: To investigate the efficacy of the H1 antihistamine promethazine against early anaphylactic reactions to antivenom. DESIGN: Sequential randomised, double blind, placebo controlled trial. SETTING: Public hospital in a venom research institute, São Paulo, Brazil. PARTICIPANTS: 101 patients requiring antivenom treatment after being bitten by bothrops snakes. INTERVENTION: Intramuscular injection of promethazine (25 mg for adults and 0.5/kg for children) or placebo given 15-20 min before starting intravenous infusion of antivenom. MAIN OUTCOME MEASURES: Incidence and severity of anaphylactic reactions occurring within 24 hours after antivenom. RESULTS:Reactions occurred in 12 of 49 patients treated with promethazine (24%) and in 13 of 52 given placebo (25%); most were mild or moderate. Continuous sequential analysis indicated that the study could be interrupted at the 22nd untied pair, without preference for promethazine or placebo. CONCLUSION: Prophylaxis with promethazine does not prevent early reactions. Patients should be observed carefully during antivenom infusion and the subsequent few hours.
RCT Entities:
OBJECTIVE: To investigate the efficacy of the H1 antihistamine promethazine against early anaphylactic reactions to antivenom. DESIGN: Sequential randomised, double blind, placebo controlled trial. SETTING: Public hospital in a venom research institute, São Paulo, Brazil. PARTICIPANTS: 101 patients requiring antivenom treatment after being bitten by bothrops snakes. INTERVENTION: Intramuscular injection of promethazine (25 mg for adults and 0.5/kg for children) or placebo given 15-20 min before starting intravenous infusion of antivenom. MAIN OUTCOME MEASURES: Incidence and severity of anaphylactic reactions occurring within 24 hours after antivenom. RESULTS: Reactions occurred in 12 of 49 patients treated with promethazine (24%) and in 13 of 52 given placebo (25%); most were mild or moderate. Continuous sequential analysis indicated that the study could be interrupted at the 22nd untied pair, without preference for promethazine or placebo. CONCLUSION: Prophylaxis with promethazine does not prevent early reactions. Patients should be observed carefully during antivenom infusion and the subsequent few hours.
Authors: J L Cardoso; H W Fan; F O França; M T Jorge; R P Leite; S A Nishioka; A Avila; I S Sano-Martins; S C Tomy; M L Santoro Journal: Q J Med Date: 1993-05
Authors: Roger Smalligan; Judy Cole; Narcissa Brito; Gavin D Laing; Bruce L Mertz; Steven Manock; Jeffrey Maudlin; Brad Quist; Gary Holland; Stephen Nelson; David G Lalloo; Gonzalo Rivadeneira; Maria Elena Barragan; Daniel Dolley; Michael Eddleston; David A Warrell; R David G Theakston Journal: BMJ Date: 2004-11-13
Authors: H Asita de Silva; Arunasalam Pathmeswaran; Channa D Ranasinha; Shaluka Jayamanne; Senarath B Samarakoon; Ariyasena Hittharage; Ranjith Kalupahana; G Asoka Ratnatilaka; Wimalasiri Uluwatthage; Jeffrey K Aronson; Jane M Armitage; David G Lalloo; H Janaka de Silva Journal: PLoS Med Date: 2011-05-10 Impact factor: 11.069