T44.6+ (X43.99/X63.99/Y13.99)
*Notifiable condition.
DESCRIPTION
Amitraz is a pesticide/insecticide which is an α2-adrenergic agonist. It is usually formulated as a tick dip for dogs, cattle and sheep. Commercial formulations contain up to 20% of amitraz in organic solvents. Poisoning may occur when amitraz is ingested or absorbed via the skin or by inhalation.
Where the history is of an unspecified rat poison or pesticide ingestion, consider other active ingredients such as super-warfarin anticoagulants and organophosphates.
Patients with acute poisoning present with:
- impaired consciousness
- bradycardia
- drowsiness
- respiratory depression
- vomiting
- hypothermia
- hypotension
- generalized seizures
- constricted pupils or rarely, dilated pupils
Other complications include:
- hyperglycaemia
- glycosuria
- mild increase in transaminases
Patients usually regain consciousness within 24 hours.
Note: Amitraz poisoning can be confused with organophosphate poisoning; whilst amitraz causes central nervous system depression, bradycardia, miosis and respiratory depression, it does not cause excessive sweating and salivation, urinary and faecal incontinence or muscle fasciculation which are seen with organophosphate poisoning. Furthermore, organophosphate toxicity results in reduced serum pseudocholinesterase levels.
GENERAL MEASURES
Decontamination of skin and clothes where applicable.
Supportive and symptomatic treatment to maintain patent airway, adequate respiration and circulation.
Mechanical ventilation may be needed in some cases.
Keep patient warm.
MEDICINE TREATMENT
- Activated charcoal, once patient is stabilised.
For severe bradycardia: R00.1 + (T44.6/X43.99/X63.99/Y13.99)
Manage with atropine - see Heart block (second or third degree).
For seizures: R56.8 + (T44.6/X43.99/X63.99/Y13.99)
Treat with benzodiazepines - see Status epilepticus.
Note: Phenytoin should be avoided (due to potential cardiotoxicity).