rodenticide induce anticoagulation in most of products , some with zinc phosphide
those with zinc phosphide poisoning , there is no antidote , mortality 30-90% and the management supportive only , main organs should focus on are lung, heart and (liver)hepatic failure , dont forget to focus in hx that there is long time between ingestion and clinical presentation of toxicity
in general Rodenticide classified into either anticoagulant , non-anticoagulant
non anticoagulant : it is rarely used
anticoagulant : which is the most common rodenticide
there are two generations :
first generation : warfarin anticoagulant
if ingested one time of small amount , harmless and dont cause bleeding
significant coagulopathy require large amount in single dose or repetitive ingestions over several days
if single large dose ingested , coagulopathy take place within 12-48hrs (warfarin biological half life is about 20-60hrs )
second generation : superwarfarin , which are highly toxic , more potent , more prolonged anticoagulant
coagulopathy occur within 24-48hrs
management :
1-for single low dose : no management needed in ingestion of low dose one time(accidently) of first generation , for asymptomatic pt who have accidently ingest suprerwarfarin , should monitored for 24-48hrs
2-for potentially toxic dose :
consider activated charcoal (1g/kg initially we give 50-100g) if 1-2hr post ingestion
investigation should done : INR (1.1 or below are normal) and prothrombin time (pt) and repeat each 12-24hrs
vitamin k indicated if INR >2(dose 20mg/day divided in 4 doses in adult , 1-5mg in children )
if INR elevated but there is no active hemorrhage , oral vitamin k is recommended
3- for pt have acute hemorrhage :
resuscitate with n/s or blood transfusion
vit k 10mg iv infusion slowly
replacement of clotting factors with FFP
in absence of active hemorrhage , no coagulopathy , normal INR , empiric vit k is contraindicated
(ref : tintinallis emergency medicine , medscape)