Amphetamines

Question 1

Source of exposure of amphetamine toxicosis

Answer 1

accidental ingestion

Question 2

Toxicokinetics of amphetamines

Answer 2

highly lipid soluble, readily absorbed orally
widely distributed including CNS
metabolized in the liver

Question 3

MoA of amphetamine toxicosis

Answer 3

CNS stimulant
blocks reuptake of norepinephrine and dopamine, inhibits MAO
dopamine excitatory receptor agonist
peripherally - sympathomimetic effect - releasing norepinephrine and direct stimulate effect on a-adrenergic receptors and B-adrenergic receptors

Question 4

Clinical signs of amphetamine toxicosis

Answer 4

hyperactivity, restlessness, circling, tremors, ataxia, seizures, mydriasis, hyper salivation, hyperthermia
some animals also show depression, weakness, and bradycardia

Question 5

Diagnosis of amphetamine toxicosis

Answer 5

hypoglycaemia
tremors may result in metabolic acidosis and rhabdomyolysis (myoglobinuria and renal failure - rare)
Chem - amphetamines can be detected in blood urine and saliva

Question 6

Treatment of amphetamine toxicosis

Answer 6

induction of emesis, activated charcoal
pentobarbital and propofol for seizures
Benzos not recommended because may cause CNS stimulation
treat hyperthermia
treat tachycardias with beta blockers or lidocaine
urinary acidifiers (ammonium chloride or ascorbic acid) enhance renal excretion
IV fluids