Ceila Maria Sant’Ana Malaque

Sequential randomised and double blind trial of promethazine prophylaxis against early anaphylactic reactions to antivenom for bothrops snake bites

Abstract 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. Key messages Antivenom therapy may cause early anaphylactic reactions Various drugs are used to prevent reactions, but none have been tested in randomised controlled studies This study showed that promethazine is not better than placebo at preventing early reactions Although most reactions are mild or moderate, trials of other drugs should be done to reduce frequency of anaphylaxis

Clinical and epidemiological features of definitive and presumed loxoscelism in São Paulo, Brazil

A retrospective study analysed 359 proven or presume cases of loxoscelism seen at the Hospital Vital Brazil, Instituto Butantan, São Paulo, Brazil, between 1985 and 1996. The spider was identified in 14%. The bites occurred predominantly in the urban areas (73%) between September and February. Patients > 14 years were commonest inflicted (92%) and 41% were bitten while getting dressed. Only 11% sought medical care within the first 12 hours post bite. Cutaneous loxoscelism was the commonest form presenting (96%); commonest manifestations were: pain (76%), erythema (72%), edema with enduration (66%), ecchymosis (39%). Skin necrosis occurred in 53% of patients, most frequently seen on trunk, thigh and upper arm, and when patients seek medical care more than 72 hours after bite. Local infection was detected in 12 patients (3%). Hemolysis was confirmed in 4 cases (1.1%). Generalised cutaneous rash, fever and headache were also observed in 48% of the total of patients. None of them had acute renal failure or died. Treatment usually involved antivenom administration (66%), being associated with corticosteroids (47%) or dapsone (30%). Presumptive diagnosis of loxoscelism may be established based on clinical and epidemiological findings. Further investigations are required to prove the value of antivenom and other treatment schedules.

Epidemiologic and clinical survey of victims of centipede stings admitted to Hospital Vital Brazil (São Paulo, Brazil).

We retrospectively analyzed 98 proven cases of centipede stings admitted to Hospital Vital Brazil, Butantan Institute, São Paulo, Brazil, between 1990 and 2007. Most stings occurred at the metropolitan area of São Paulo city (n=94, 95.9%), in the domiciles of patients (n=67, 68.4%), and during the warm-rainy season (n=60, 61.2%). The mean age of the victims was 32.0+/-18.8-years-old. Cryptops and Otostigmus genera were responsible for most cases. Around 86% of the patients sought medical care within 6h after the sting. Both lower (56.1 %) and upper limbs (41.8 %) were most frequently bitten, especially the feet and hands (89.8%). The most frequent local clinical manifestations were pain (94.9%), erythema (44.9%) and edema (21.4%), and the latter was mainly observed in patients bitten by Otostigmus spp. Supportive treatment was used in only 28.6% of the patients, namely administration of local anesthesia (9.2%) and systemic analgesia (13.3%). No sequels or complications were observed in patients, and the prognostic was benign.