cartap is a pesticide that was first introduced into the market in japan in 1967 .
its commercial names include padan , kritap , ag - tap , thiobel , and vegetox .
its basic chemical structure is s , s-[2-(dimethylamino)-1 , 3-propanediyl ] dicarbamothioate [ figure 1 ] .
it is used for the control of chewing and sucking pests and results in insect paralysis .
it has been categorized as a high - effectiveness , low - toxicity , and low - residue pesticide used in rice and sugarcane fields .
it is generally considered to be a safe compound with oral ld50 in the monkey of 100 - -200 mg / kg body weight .
however , subsequent studies have shown that ocular instillation can result in diaphragmatic contracture and death in rabbits .
we report a case of intentional ingestion of cartap hydrochloride as a suicidal attempt in a farmer which subsequently resulted in severe respiratory failure .
a 27-year - old male agricultural laborer from tamil nadu , india , presented with alleged consumption of 50 ml of an unknown poison as an act of deliberate self - harm following a quarrel with his spouse .
subsequently , he developed twitching movements of his limbs , urinary incontinence , and altered sensorium .
he had a systolic blood pressure of 80 mm of hg , a heart rate of 120/min , and a respiratory rate of 32/min .
a gastric lavage was administered followed by a single dose of activated charcoal instilled through the nasogastric tube .
the provisional diagnosis made in the emergency department was of an organophosphate poisoning with acute cholinergic syndrome .
basic blood investigations including serum electrolytes , creatinine , liver function tests , and complete blood counts were normal .
the patient was admitted into the semi - intensive care unit and managed conservatively with fluids and cardiac monitoring .
the plan was to use atropine if the patient developed bradycardia or miosis and to repeat serum pseudo - cholinesterase levels after 24 hours .
twenty - four hours after presentation , the relatives were able to provide the name and container of the poison which was cartap hydrochloride 4 gm/50% sp . at 24 hours
he was subsequently extubated . due to the fact that there is insufficient data regarding effective timing of the antidote , and the significant clinical recovery of our patient
cartap has been recognized as an analog of nereistoxin which is a neurotoxic substance initially isolated from the annelid lumbriconereis heteropoda .
the other nereistoxin analogs that are in use are bensultap , thiocyclam , and thiosultap .
its primary action was earlier considered to be by direct action on and inhibition of the postsynaptic nicotinic acetylcholine receptor ( achr ) ion channels . due to this action
it was believed that cartap hydrochloride would act as a neuromuscular blocker and hence result in respiratory paralysis in the setting of acute toxicity . a study published by liao et al .
challenges this belief based on studies of ocular cartap exposure in mice and its action on the phrenic nerve .
the conclusion was that the effect on the diaphragm was not due to neuromuscular paralysis but instead due to persistent diaphragmatic contraction resulting in respiratory failure .
cartap may exert this effect primarily by promoting extracellular ca influx and induction of internal ca release .
cartap inhibits the [ h]-ryanodine binding to the ca2 + release channel in the sarcoplasmic reticulum in a dose - dependent manner .
it was hypothesized that cartap - induced contracture was , to a minor extent , a result of inhibition of the sarcoplasmic reticulum ca pump protein ca atpase .
inhibition of the atpase would result in the unloading of calcium from the sarcoplasmic reticulum .
there have been a few reports of human toxicity in japan and india as part of occupational exposure .
acute toxicity of the compound that has been described is nausea , vomiting tremulousness , salivation , spasms , dyspnea , and mydriasis .
sodium dimercaptopropane sulfonate ( dmps ) and sodium dimercaptosuccinate ( dms ) were discovered to be effective antidotes for acute poisoning of insecticides like scd [ sodium ammonium dimethyl-2-(propane-1 , 3-dithiosulfate ) monohydrate ] , nereistoxin , and cartap in mouse models .
cysteine was found to be of lower effectiveness and shorter duration of action than these compounds . at present
the recommended antidotes for cartap poisoning are an intravenous injection of 100200 mg of l - cysteine or an intramuscular injection of 2060 mg of british anti lewisite ( dimercaprol ; 2 , 3-dimercapto propanol ) .
it is possible that the effect of calcium binding of these antidotes is central to the antagonistic effects on respiratory depression in cartap toxicity . to the best of our knowledge
this is the first reported case of cartap hydrochloride poisoning as a result of deliberate self - harm that manifested with acute respiratory distress and altered sensorium .
 cartap hydrochloride , a nereistoxin analog , is a commonly used low toxicity insecticide . 
 we describe a patient who presented to the emergency department with alleged history of ingestion of cartap hydrochloride as an act of deliberate self - harm . 
 the patient was managed conservatively . to our knowledge 
 this is the first case report of cartap hydrochloride suicidal poisoning . 
 cartap toxicity has been considered to be minimal , but a number of animal models have shown significant neuromuscular toxicity resulting in respiratory failure . it is hypothesized that the primary effect of cartap hydrochloride is through inhibition of the [ 3h]-ryanodine binding to the ca2 + release channel in the sarcoplasmic reticulum in a dose - dependent manner and promotion of extracellular ca2 + influx and induction of internal ca2 + release . 
 this results in tonic diaphragmatic contraction rather than paralysis . 
 this is the basis of the clinical presentation of acute cartap poisoning as well as the treatment with chelators namely british anti lewisite and sodium dimercaptopropane sulfonate . 
Introduction
Case Report
Discussion