TOXICOKINETICS OF ACUTE STRYCHNINE POISONING

Background: Strychnine competes with the inhibitory neurotransmitter g lycine producing an excitatory state characterized clinically by hyper reflexia, severe muscle spasms, and convulsions. However, the kinetics after overdose have not been well described. Case Report: A 34-year-o ld male presented to the emergency department 20 minutes after ingesti ng half of a 250-mL container of 2% strychnine sulfate (2.25 g). The r eported lethal dose is 100-120 mg. He was alert and oriented and exper iencing muscle spasms. His condition deteriorated prompting sedation, muscle paralysis, and tracheal intubation. He was given activated char coal 100 g per nasogastric tube, He was admitted to intensive care whe re he was managed with diazepam, pentobarbital, and pancuronium. Despi te mild rhabdomyolysis, he recovered and was extubated on day three. A lthough receiving prophylactic heparin therapy, a massive fatal pulmon ary embolus ensued. Eighteen blood specimens for strychnine analysis w ere obtained from 20 minutes to 51 hours after ingestion. Serum concen trations were determined with gas chromatography-mass spectroscopy. Di sappearance followed a first-order process with a t(1/2) of 16 hours ( r(2) = 0.97), Discussion: Our results confirm the findings of an earli er case report of 19 strychnine levels obtained between 4 and 19 hours which described first-order kinetics with a similar trh of 10 hours. Conclusion: Strychnine disappearance in this overdose was well describ ed by a first-order process with a t(1/2) of 10-16 hours.