• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.255-261
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• 1995

Amitraz frequently causes the side effect of intestinal stasis or bloat in mammals. It is very similar to the side effect of xylazine or clonidine which produce the inhibition of intestinal motility through the stimulation of ${\alpha}_2$ adrenoceptor. Therefore, we examined whether amitraz causes intestinal stasis or bloat through the inhibition of intestinal motility or whether amitraz produces the inhibition of intestinal motility through the stimulation of ${\alpha}_2$ adrenopceptor. Amitraz inhibited the intestinal motility in a dose-dependent manner in isolated rabbit jejunum and isolated pig ileum. These inhibitory effects of amitraz were blocked by yohimbine but not by prazosin. The effect of intestinal contraction of carbachol or high-potassium was not affected by the pretreatment of amitraz. However, the con-traction of histamine was inhibited by the pretreatment of amitraz. It is concluded that amitraz mainly inhibits the intestinal motility through the stimulation of ${\alpha}_2$-adrenoceptor although partially antihistaminic action of amitraz can be involved.

• Korean journal of applied entomology
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• v.32 no.2
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• pp.176-183
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• 1993

These sutdies were conducted to investigate the joint toxic action of mixtures of several acaricides including amitraz, bifenthrin, propargite, fenbutatin dxide and bxide dicofol to the field-collected strian of Tetranychus urticae. The synergistic action of acaricidal mixtures was greatly varied with the kind of acaricide combinations and their mixture ratios. The combinations of amitraz with each of the tested acaricides were synergized at the given mixture ratios. The higher synergistic action in the each combination was observed at 2 : 8 ratio of amitraz and bifenthrin, 8 : 2 ratio of amitraz and fenbutatin oxide, 4 : 6 ratio of amitraz and propargite and 6 : 4 ratio of amitraz and dicofol.

• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.209-213
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• 1998

난치성 전신성 모낭충증에 감염되어 약 4개월간 모낭충 치료제인 amitraz(0.0125%) 처치에도 불구하고 치유되지 않은 한국산 풍산개 2두에 대한 ivermectin 및 amitraz 의 병용치료효과를 알아보았다. 전신성 모낭충증은 신체의 50% 또는 4개의 발에 모두 모낭충 이 검출된 것으로 정의하였다. 내원시 신체검사, 심장사상충검사 및 최소 裂訃위에 대한 피부 박리검사를 실시하여 모낭충을 진단하였고 치료는 돼지용 ivermectin을 체중 kg당 0.5 mg을 피하로 매일 주사하였으며 1주일에 2회 amitraz 약욕을 실시하였다. 피부농피중은 cephalexin 20 mg/kg을 경구로 일일 2회 투여하여 치료하였다. 치료후 4주에 피부병변이 치유되기 시 작하였으며 6주에는 탈모 및 소수의 발진을 제외하고는 피부병변이 정상으로 회복하였다. 피 부박리검사는 6주에 모낭충이 검출되지 않았다. 이들 제제에 의한 부작용은 관찰되지 않았으며 매일 ivermectin 투여와 amitraz 약욕치료의 병용치료는 amitraz로 치료가 되지 않는 난치성의 전신성 모낭충증에 대한 치료기간을 단축시키는 효과적인 치료방법으로 생각된다.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.381-385
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• 1993

수의학 및 농업분야에서 널리 사용되고 있는 살충제인 amitraz의 효과를 척출 돼지 자궁근에서 검토하였다. Amitraz($10^{-8}{\sim}10^{-6}M$)는 발정정지기의 자궁근 수축성을 용량의존적으로 증가시켰다. Amitroaz의 이 효과는 yohimbine($10^{-8}{\sim}10^{-7}M$)에 의해 용량의존적으로 차단되었으나, prazosin($10^{-6}M$)에 의해서는 억제되지 않았다. 또한 $Ca^{2+}$-free Tyrode's solution에서나 verapamil($3{\times}10^{-5}M$)의 전처치에 의해서 amitraz의 수축효과는 완전히 억제되었다. 따라서 amitraz에 의한 발정정지기 돼지 자궁근의 수축은 ${\alpha}_2$-adrenoceptor가 중개하며 이 효과는 주로 $Ca^{2+}$ entry blocker에 감수성이 있는 $Ca^{2+}$ channel을 통한 extracellular $Ca^{2+}$ influx의 증가에 의한 것으로 여겨진다.

• Journal of The Korean Society of Clinical Toxicology
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• v.5 no.2
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• pp.123-125
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• 2007

Amitraz is a formamidine-derived insecticide and acaricide which is commonly used throughout the world. Amitraz intoxication is mediated through ${\alpha}_2$ adrenergic receptor agonist effects, similar to those of the ${\alpha}_2$ agonist clonidine. We report a case of a patient who experienced coma and hypotension after amitraz ingestion. A 37-year-old woman visited the ER with symptoms of vomiting and altered mental state. She had ingested a mouthful of liquid amitraz concentrate (12.5%), which rapidly led to vomiting, hypotension, bradycardia, hyperglycemia, and mental stupor. Supportive treatment, including mechanical ventilation and administration of inotropics, resulted in full recovery within four days.

• Journal of The Korean Society of Clinical Toxicology
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• v.6 no.1
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• pp.52-56
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• 2008

Amitraz is used as farm-animal insecticide. Its side effects in humans are related to its pharmacological activity on alpha 2-adrenergic receptors. The case describes a previously healthy 46-year-old woman who intentionally ingested approximately 250mL of liquid amitraz. She presented with vomiting, altered mental status, miosis, dry mouth, hypopnea, metabolic and respiratory acidosis, hypotension, hypothermia, polyuria, metabolic acidosis, elevated serum aminotransferase and abdominal distension. Supportive treatments including mechanical ventilation, hydration, dopamine infusion, bicarbonate infusion and gastric decompression resulted in improvement. By hospital day 3, she recovered with resolution of abdominal distension. It is paramount to recognize amitraz poisoning when a pesticide-intoxicated patient presets with signs and symptoms consistent with organophosphate intoxicated patients but with greater alpha 2-adrenergic related symptoms such as decreased bowel motility and xerostomia.

• Korean Journal of Veterinary Research
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• v.48 no.1
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• pp.33-38
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• 2008

In veterinary medicine amitraz has been used as an insecticide to eliminates mites, lice, and ticks in dogs, cats, goats, swine and cattle. The objective of present study was to developed an analytical method using one-step extraction and determination of the amitraz in veterinary drugs by liquid chromatography (LC). The amitraz was analyzed by LC equipped with Waters XTerra RP18 ($4.8{\times}250mm;\;5{\mu}m;\;Waters,\;USA$) analytical column, using 75% acetonitrile (acetonitrile/D.W; 75/25) at 1.0 ml/ min. The UV-VIS detection of amitraz was made at 290 nm. Calibration graphs were linear with very good correlation coefficients ($r^2>0.9999$) from $80{\sim}120{\mu}g/ml$. The limit of detection was $0.09{\mu}g/ml $ and limit of quantification was $0.27{\mu}g/ml $. The method showed good intra-day precision (CV 0.05~0.09%) and inter-day precision (CV 0.06~0.18%).

• Korean Journal of Veterinary Research
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• v.39 no.4
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• pp.710-714
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• 1999

In veterinary medicine amitraz has been used as an insecticide to eliminate mites, lice, and ticks in dogs, cats, goats, swine and cattle. We performed the experiment on bradycardiac effect of arnitraz in rabbits. Under anesthetized with urethane (1g/kg, 25% w/v, SC), the femoral artery was cannulated by a polyvinyl tube which was connected with pressure transducer for continuous measurement of heart rate. Amitraz (0.5-2.5mg/kg, IV) reduced the heart rate in a dose-dependent manner. Pretreatment of yohimbine (2.0mg/kg) or atropine (2.0mg/kg and 4.0mg/kg) affected the response of amitraz but pretreatment of prazosin (0.5mg/kg) or propranolol (1.0mg/kg) did not. Moreover, the effect of amitraz was blocked by vagotomy. The result of our experiment suggest that amitraz may reduce the heart rate by increasing acetylcholine through activating vagal nerves and ${\alpha}_2$-adrenoceptors could be involved in activating vagal nerves.

• Korean Journal of Veterinary Research
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• v.50 no.3
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• pp.253-257
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• 2010

A 3-year-old female Thoroughbred racehorse was presented following the accidental oral and skin administration of amitraz. This case report describes the clinical signs and the treatment of this horse. Clinical signs of amitraz toxicosis are associated with the stimulation of alpha2-adrenergic receptors. Amitraz is seldom fatal because the effects can be reversed by alpha2-adrenergic antagonists. The horse displayed typical clinical signs of colic, including pawing, small hard drops, tranquillisation, depression, ataxia, muscular incoordination and impaction colic lasting up to 7 days. The syndrome was accompanied by mild dehydration. The horse survived after persistent symptomatic treatment, including the giving of intravenous fluids, antibiotics, multiple doses of mineral oil per os, nonsteroidal anti-inflammatory drugs and dexamethasone intramuscularly and intravenously.

• Journal of Life Science
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• v.14 no.4
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• pp.547-552
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• 2004

The present study was carried out to investigate the potential acute toxicity of amitraz by a single subcutaneous dose in beagle dogs. The test chemical was administered subcutaneously to male beagle dogs at dose levels of 0, 2, 10, or 50 mg/kg. Mortalities, clinical findings, and body weight changes were monitored for the 14-day period following the administration. At the end of 14-day observation period, hematology, serum biochemistry, and gross postmortem examinations were examined. A single dog in the 50 mg/kg group was found dead on day 3 after treatment and the other two dogs in the group were sacrificed because of the severe clinical signs on day 7 after treatment. Treatment related clinical signs, including anorexia, edema, mass and abscess formation in the injection sites, depression, vomiting, lacrimation, decreased locomotor activity, ataxia, recumbency, paresis in the limbs, and/or moribundity were observed in all treatment groups in a dose-dependent manner. Decreased or suppressed body weight gain was also observed dose-dependently in all treated groups. In autopsy, dead animals in the 50 mg/kg group showed muscular hemorrhage and inflammation in the injection sites and congestion in the liver and kidney. The terminal sacrificed animals in the 10 mg/kg group also exhibited muscular hemorrhage and inflammation in the injection sites. Whereas, no treatment related effects on hematology and serum biochemistry were observed on day 14 after treatment at any dose tested. On the basis of the results, it was concluded that a single subcutaneous injection of amitraz to beagle dogs resulted in increased incidence of abnormal clinical signs and death, decreased body weight, and increased incidence of abnormal gross findings. In the experimental conditions, the $LD_{50}$value of amitraz was 22.3 mg/kg (95% confidence limit not specified) and the no-observed-adverse-effect level (NOAEL) was considered to be below 2 mg/kg for male dogs.