Effectiveness of Alpha Chymotrypsin on the Treatment of Severe Paralysis due to Bungarus Multicinctus Snakebite

In Vietnam, there are two main species of Bungarus: Bungarus multicinctus and Bungarus candidus. Trypsin is a serine protease digestive enzyme that has demonstrated efficacy in some of Elapidae envenomations. After their experiments with dogs and mice, Hsiung Yu-Liang et al. concluded the local injection of trypsin can be used in clinical practice as a new and effective therapy for snakebite. We report a case of successful application of alphachymotrypsin, a related enzyme, in the treatment of severe paralysis due to B. multicinctus snakebite.
A 38-year-old man was bitten on his left hand by B. multicinctus. Two hours after the bite, the patient developed a sore throat, diffuse myalgia, and progressive paralysis. Since antivenom was not available, we decided to administer alphachymotrypsin after the risks and benefits were carefully discussed. A dose of 5000 IU alphachymotrypsin was administered by the IM route at 24 and 31 hours after bite. At the time of the first dose of alphachymotrypsin, muscle power was 0/5. The muscle power improved rapidly, from 0/5 (24 hours) to 2/5 (at 44 hours). After that, additional doses of 10.000 IU of alphachymotrypsin were administered at 45, 55, 69, 75, 94 and 100 hour after the bite; the muscle power increased gradually then to 3/5 (66 hours), 4/5 (75 hours), and 5/5 (97 hours).
The severity of the patient can be estimated through some factors as following: the heavier and longer the nake, the more severe the threat, time from bite to symptoms: the sooner the more severe, the level of paralysis, and the level of hyponatremia. According to these signs, the patient was classified under the severe group because the snake was long and heavy (1.5 m and 300 gr), symtoms appeared right after 2 hours after the bite, and level of paralysis was 0/5 17 hours after the bite. The mild hyponatremia could be related to either a minor B. multicinctus envenomation, which is unlikely given the severity of the other clinical findings, or the effectiveness of alphachymotrysin. This hypothesis requires further investigation, both mechanistically and clinically.
The use of alphachymotrypsin was associated with a shortening of the need for mechanical ventilation, length of ICU stay, and a reduced extent of hyponatremia in a patient with severe B. multicinctus envenomation.