Methomyl is a carbamate insecticide widely used in pesticides. Most of the poisoning methods are through digestive tract, respiratory tract and skin contact. At present, there is no report of poisoning caused by intramuscular injection. A case of poisoning caused by intramuscular injection of methomyl was analyzed retrospectively. About 4 minutes later, cholinergic crisis and central inhibition occurred. Venovenous-Extracorporeal Membrane Oxygenation (VV-ECMO) and atropine were given quickly. Finally, the patient was successfully rescued and had a good prognosis. After intramuscular injection of methomyl, cholinergic crisis can occur rapidly, and the onset rate is significantly faster than that of digestive tract, respiratory tract and skin contact.
Humans ; Retrospective Studies ; Methomyl ; Insecticides ; Pesticides ; Cholinergic Agents

We observed and analysed relating problems concerned to 21 patients of the acute carbamate intoxications, visited the emergency room of cheonju Presbyterian Medical center, from Oct 1993 to july 1996. The results were as follows : 1) Male was more prevalent than female with a ratio of 2:1 in sex distribution and the highest incidence of age group was in third decade and sixth decade of age in male sex 2) the most common drug of intoxication was deltanet in 7 cases, the remainders were bassa in 3 cases, b.p in 3 cases, huradan, qratel and methomyl in 2 cases, each, in order of frequency. 3)Among the exposed carbamate in 13 patients with respiratory failure, detanet was the most common in 6 cases, b.p in 3 cases, methomyl in 2 cases, bassa and huradan each in 1 case. 4) The serum ChE activity of patients were significantly reduced compare to normal.8 patients were between 20~50% of normal,8 patients were above 50% of normal, 4 patients were between 10~20% of normal, only 1 patient was below 10~20% of normal. 5) In 13 patients with respiratory failure, seam ChE activities were below 50% of normal. 6) In all patients with respiratory failure except 1 case time to recovery of the respiratory failure was below 48hrs. 7) Mean dose of atropine administered within first full atropinization and fist 24 hours was significantly higher in patients with than patients without respiratory failure in staitistics(29.3+/-23.3mg, 54.5+/-49.5mg VS 7.6+/-3.6mg, 13.6+/-6.9m) 8) 3 patients among a total of 21 patients expired. So that motality rate was 14.3%. Among the expired cases, 1 patients discontinued treatment due to economic problems and only 2 patients died in hospital during the treatment.
Atropine ; Emergency Service, Hospital ; Female ; Humans ; Incidence ; Male ; Methomyl ; Protestantism ; Respiratory Insufficiency ; Sex Distribution

Drug-induced interstitial nephritis is one of the causes of acute kidney injury. Although methomyl is widely used as an insecticide in many countries, methomyl-induced interstitial nephritis has not been reported thus far in the general population. We report a case of a 39-year-old male patient with acute allergic tubulointerstitial nephritis due to methomyl intoxication. He took methomyl 250 mL to commit suicide. He was treated with hemodialysis, but his renal function continued to deteriorate. Kidney biopsy demonstrated mononuclear cell and some eosinophils infiltration into the renal interstitium with tubular invasion. Immediate steroid pulse therapy, appropriate education, and conservative management resulted in gradual restoration of his renal function. This case suggests that methomyl may be a causative allergen inducing acute interstitial nephritis in some patients.
Acute Kidney Injury ; Adult ; Biopsy ; Education ; Eosinophils ; Humans ; Kidney ; Male ; Methomyl ; Nephritis ; Nephritis, Interstitial* ; Renal Dialysis ; Suicide

On February 21, 2013, 6 elderly people collapsed abruptly after eating bean sprout bibimbab (boiled rice mixed with bean sprouts and seasoned with soybean sauce) at a countryside restaurant in the Chungbuk Province, Korea. Minutes after eating the meal, all of the patients lapsed into a state of stupor. Respiratory arrest developed in 2 patients; and one of two patients died of cardiac arrest. The autopsy identified methomyl and methanol in the deceased patient's gastric contents and in the remaining soybeanbean sauce seasoning. Five of the 6 patients ingested one spoonful of the soybeanbean sauce seasoning and survived, while one patient who died of cardiac arrest, ingested approximately two spoons. Symptoms of toxicity presented quickly in the subjects and progressed rapidly, including chest tightness, an unusual sensation in the pit of the stomach, dizziness, ataxia, and finally, collapse. Three patients who drank ethanol with the meal experienced only mild toxic symptoms. Our analysis of the clinical observations in these cases suggests that ingestion of methomyl pesticide and the additive toxicity of methanol may have been responsible for the intoxication.
Aged ; Cholinesterase Inhibitors/poisoning ; *Disease Outbreaks ; Ethanol ; Female ; Foodborne Diseases/*epidemiology ; Humans ; Insecticides/*poisoning ; Male ; Methanol/*poisoning ; Methomyl/*poisoning ; Republic of Korea/epidemiology

BACKGROUND: Organophosphate and carbamate insecticides have been used extensively in agriculture resulting in serious increases in poisoning. Levels of poisoning by carbamates and organic phosphorus compounds and the severity of associated symptoms are dependent not only on the degree of reduction of acetylcholinesterase activity in the nervous system but also on the rate of inhibition and the type of inhibitive action. The most striking differences between the clinical effects of the two groups of compounds are the much more rapid and spontaneous recovery from poisoning by carbamates and the relatively large difference between the smallest dosage of any carbamate that will cause mild illness and the lethal dosage of the same compound. The purpose of this study is to compare the clinical characteristics of acute intoxication by organophosphate and carbamate insecticides. METHOD: We retrospectively analyzed the clinical characteristics of 41 patients poisoned with organophsphates and 12 patients poisoned with carbamates, who were admitted to the department of internal medicine, Soonchunhyang Chunan hospital from January 1995 to December 1996. RESULTS: 1) The most common organophosphate was EPN (9 cases) followed by Dichlorvos (7 cases). In the carbamates group, Carbofuran (5 cases) was the most common followed by Methomyl (3 cases).2) The main cause of poisoning was ingestion for the purpose of suicide in both groups.3) The severity of poisoning was more acute in the organophosphate group than in the carbamate group.4) Altered consciousness and respiratory depression occurred more frequently in the organophosphate group than in the carbamate group. Six cases out of the organophosphate group suffered from respiratory depression 24 hours to 96 hours after poisoning.5) The activity of serum cholinesterase showed no significant difference between poisoning with organophosphates and with carbamates.6) The mortality rate was 22% in organophosphate intoxication and 16.7% in carbamate intoxication. The most common complication of organophosphate and carbamate intoxication was aspiration pneumonia. CONCLUSION: Carbamate insecticides exhibited less toxicity than organophosphates.
Acetylcholinesterase ; Agriculture ; Carbamates ; Carbofuran ; Cholinesterases ; Chungcheongnam-do ; Consciousness ; Dichlorvos ; Eating ; Humans ; Insecticides* ; Internal Medicine ; Methomyl ; Mortality ; Nervous System ; Organophosphates ; Phosphorus Compounds ; Pneumonia, Aspiration ; Poisoning* ; Respiratory Insufficiency ; Retrospective Studies ; Strikes, Employee ; Suicide

OBJECTIVETo study the toxicity of methomyl to acetylcholinesterase (AChE) in different regions.

METHODSThe optimal temperature and time for measurement of AChE activity were determined in vitro. The dose- and time-response relationships of methomyl with AChE activity in human erythrocyte membrane, rat erythrocyte membrane, cortical synapses, cerebellar synapses, hippocampal synapses, and striatal synapses were evaluated. The half maximal inhibitory concentration (IC50) and bimolecular rate constant (K) of methomyl for AChE activity in different regions were calculated, and the type of inhibition of AChE activity by methomyl was determined.

RESULTSAChE achieved the maximum activity at 370 °C, and the optimal time to determine initial reaction velocity was 0-17 min. There were dose- and time-response relationships between methomyl and AChE activity in the erythrocyte membrane and various brain areas. The IC50 value of methomyl for AChE activity in human erythrocyte membrane was higher than that in rat erythrocyte membrane, while the Ki value of methomyl for AChE activity in rat erythrocyte membrane was higher than that in human erythrocyte membrane. Among synapses in various brain areas, the striatum had the highest IC50 value, followed by the cerebellum, cerebral cortex, and hippocampus, while the cerebral cortex had the highest Ki value, followed by the hippocampus, striatum, and cerebellum. Lineweaver-Burk diagram demonstrated that with increasing concentration of methomyl, the maximum reaction velocity (Vmax) of AChE decreased, and the Michaelis constant (Km) remained the same.

CONCLUSIONMethomyl is a reversible non-competitive inhibitor of AChE. AChE of rat erythrocyte membrane is more sensitive to methomyl than that of human erythrocyte membrane; the cerebral cortical synapses have the most sensitive AChE to methomyl among synapses in various brain areas.

Acetylcholinesterase ; metabolism ; Animals ; Cerebellum ; drug effects ; Cerebral Cortex ; drug effects ; Erythrocyte Membrane ; drug effects ; enzymology ; Hippocampus ; drug effects ; Humans ; Inhibitory Concentration 50 ; Methomyl ; toxicity ; Rats ; Synapses ; drug effects ; Toxicity Tests

OBJECTIVETo study the neuromuscular function and its relation with the occurrence of myasthenia in rats poisoned by dimethoate (D), phoxim (P), methomyl (M), M + D and M + P respectively.

METHODSThe stimulation single fiber electromyography(SSFEMG) at different stimulus frequencies(5, 10 and 20 Hz) was used. The whole blood cholinesterase (ChE) activity was measured 1 h before and after poisoning.

RESULTS(1) Myasthenia occurred in 5 out of 9.5 out of 10.5 out of 5, and 8 rats poisoned by D, P, M + D, and M + P, respectively. (2) The average mean consecutive differences(MCD) at 5, 10, and 20 Hz in myasthenic rats were significantly higher than those of poisoned rats without myasthenia and the control ones. (3) SSFEMG changes at 5, 10 and 20 Hz were significantly consistent with the clinical manifestation of myasthenia, especially at 10 Hz and 20 Hz. (4) ChE activity was significantly lower in rats with P or D poisoning while ChE inhibition was of no difference in rats with M, M + D, and M + P poisoning. In the D poisoning and P poisoning groups, there was no significant difference in ChE inhibition between the rats with and without myasthenia.

CONCLUSIONMuscle weakness was associated with neuromuscular transmission dysfunction, but not well correlated with ChE inhibition. The SSFEMG with stimulus frequency at 10 Hz or 20 Hz could be used to detect the neuromuscular dysfunction during myasthenia induced by organophosphate insecticides and their mixtures poisoning.

Animals ; Cholinesterase Inhibitors ; poisoning ; Dimethoate ; poisoning ; Electromyography ; Insecticides ; poisoning ; Methomyl ; poisoning ; Muscle Weakness ; chemically induced ; Myasthenia Gravis ; chemically induced ; physiopathology ; Neuromuscular Junction ; drug effects ; physiology ; Organothiophosphorus Compounds ; poisoning ; Rats ; Synaptic Transmission ; drug effects

PURPOSE: To investigate the age group characteristics of children who visited the emergency department with acute poisoning by ingestion. METHODS: We reviewed children under 19 years who visited the emergency department for acute poisoning by ingestion from 2012 to 2017. The children were divided into 3 age groups; infants (0-1 years), preschoolers (2-5 years), and schoolers (6-18 years). Clinical characteristics, intentional ingestion, involved substances (drugs, household products, artificial substances, and pesticides), decontamination and antidote therapy, and outcomes of the 3 age groups were compared. We also performed multivariable logistic regression analysis to identify factors associated with hospitalization. RESULTS: A total of 622 children with acute poisoning by ingestion were analyzed. Their annual proportions to overall pediatric emergency patients ranged from 0.3% to 0.4%. Age distribution showed bimodal peaks at 0-2 years and 15-17 years. The infants showed lower frequency of girls, intentional ingestion, ingestion of drugs, performance of decontamination and antidote therapy, and hospitalization than 2 older groups (P < 0.001). Most decontamination, antidote therapy, and hospitalization occurred in the schoolers (P < 0.001). The most frequently reported substances were household cleaning substances in the infants (18.2%), antihistamines in the preschoolers (15.8%), and analgesics in the schoolers (37.5%). The factors associated with hospitalization were intentional ingestion (adjusted odds ratio [aOR], 7.08; 95% confidence interval [CI], 2.85-17.61; P = 0.001) and schoolers (aOR, 2.33; 95% CI, 1.10-7.53; P = 0.031; compared with infants). Only 1 in-hospital mortality was found in a boy aged 2 years who ingested methomyl. CONCLUSION: Infants may experience non-intentional ingestion, ingestion of non-pharmacologic substances (especially household cleaning substances), discharge without decontamination and antidote therapy more frequently than older children. Thus, we need age group-specific, preventive and therapeutic plans for children with acute poisoning.
Adolescent ; Age Distribution ; Analgesics ; Child ; Decontamination ; Eating ; Emergencies ; Emergency Service, Hospital ; Epidemiology ; Family Characteristics ; Female ; Histamine Antagonists ; Hospital Mortality ; Hospitalization ; Household Products ; Humans ; Infant ; Logistic Models ; Male ; Methomyl ; Odds Ratio ; Poisoning