Amitraz poisoning: The (Un) common poisoning

Abstract

Pesticide poisoning is always a clinical conundrum for the emergency physician (EP), the complexity of which increases when the pesticide has no antidote! Over the past decade, there has been a sharp increase in cases of Amitraz poisoning, a pesticide routinely used in veterinary medicine, available without a prescription. The usual presentation includes bradycardia, hypotension, poor sensorium, and miosis. In the absence of accurate history, these clinical features can be confused with the cholinergic toxidrome of organophosphorus poisoning. There is a dearth of literature regarding the presentation and protocols for the management of Amitraz poisoning with data mostly based on animal studies and pediatric case reports. Currently, the available medical literature in the form of case reports and case series form an invaluable source of information to the EP to formulate a working diagnosis and methodical approach to this pesticide. Here, we present two case reports highlighting the characteristic clinical features and bringing to light how an organized approach to the toxin can give satisfactory results.

Amitraz poisoning – A case report of a common but highly misconstrued cause of poisoning in Zambia

“…There was no history of ataxia, nystagmus or convulsions. Ataxia and coma have also been attributed to solvents used for [1][2][3][4][5][6] example Xylene . Our patient's coma lasted for 36 hours, however, other studies have shown that CNS 3 depression ranged from a few hours to 24 hours .…”

“…Amitraz is normally sold as a 12.5 to 50% formulation dissolved in an organic solvent mostly 1,5 Xylene . It is used as an ectoparasite to control Demodicosis in canines, ticks and mites in cattle and sheep, Psylla in pears and also Red Spider infection [1][2][3][4][5][6] in fruit crops . Human exposure can be intentional or accidental via inhalation, skin contact or 1,4 ingestion .…”

Amitraz Poisoning: An Emerging and yet Underestimated Poison—A Review

“…Since there are no randomized trials, no conclusions can be drawn on the ideal management strategy for this poisoning. [63][64][65][66][67][68][69][70][71][72][73][74] conclusIon Amitraz poisoning occurs in either accidental or suicidal manner and is more common in children than adults. Majority of the cases have been reported from Turkey, though there has been a recent rise in the number of cases reported from South Africa and India.…”

An unusual autopsy case in which the consumption of organophosphate insecticide was not the direct cause of death

“…In humans, the inhibition of acetylcholinesterase (AChE) by OP insecticides, such as fenitrothion and malathion, causes the accumulation of acetylcholine (ACh), and leads to the overstimulation of the muscarinic receptors that induces miosis [2,4]. Although patients' pupils were miotic (1-2 mm) in clinical emergency cases of OP poisonings [5,6], in forensic autopsy cases, miosis was not always been observed owing to the elapsed time after death [7][8][9]. Conversely, the serum cholinesterase (ChE) activity markedly decreased in cases of fatal OP poisonings [7][8][9]; thus, the measurement of the deceased's serum ChE levels is used to determine the direct cause of death in acute poisoning cases caused by the ingestion of OPs [10].…”