Decreased parasympathetic activities in Malayan krait (Bungarus candidus) envenoming.

Three patients were bitten by the Malayan krait (Bungarus candidus). The patients developed ptosis and generalized muscle weakness which later progressed to respiratory paralysis. All patients showed evidence of decreased parasympathetic activity manifested by mydriasis, hypertension and tachycardia. No specific antivenom was available. All patients received assisted ventilation and supportive treatment. The other forms of treatment included administration of neostigmine, the banded krait (Bungarus fasciatus) antivenom (Thai Red Cross) and plasmapheresis without beneficial response. Two patients recovered. The other patient had permanent brain damage due to anoxia from two episodes of cardiac arrest. While hypertension resolved 6-60 days after admission, mydriasis and tachycardia persisted after discharge in all patients for between 7 days and 2 years. One patient had constipation and defect in micturition which still persisted 2 years after the bite. Decreased parasympathetic activities in Malayan krait bite are perhaps not uncommon and should be examined.