Dissociatives (Ketamine, Telazol)

Question 1

What are dissociative drugs also referred to as?

Answer 1

• Cyclohexamines
• they do not produce a ‘true’ anesthetic state but appear to cause dissociation between the thalamus and limbic systems of the brain

Question 2

What do Ketamine and Telazol act as when administered at sub-anesthetic doses?

Answer 2

They act as N-methyl-D-asparate (NMDA) antagonist

Question 3

What does Ketamine and Telazol do most effectively?

Answer 3

• block central neuronal hypersensitization (‘wind up’) in the dorsal horn of the spinal cord
• should not be used as the sole analgesic agent

Question 4

Which drug has a longer duration? Ketamine or Telazol?

Answer 4

Telazol, and it is also more expensive.

Question 5

Ketamine

Answer 5

• never administer alone
• can produce muscle and limb rigidity, increase intracranial pressure, increase intra-ocular pressure and potentiate seizures due to CNS stimulation
• depression of myocardial function
• increase in HR, BP and cardiac output
• hypersalivation
• increase risk in mucus plus in ET tube
• increased bronchial secretions
• contraindicated in depleted catecholamine stores (severe trauma, shock and stress)
• direct depressant effect will dominate
• emergence delirium seen if only agent on board at time of recovery
• excitement, vocalisation, hallucinatory behavior, ataxia, hyperreflexia, hyperthermia, increased muscle activity
• does not undergo hepatic metabolism in cats
• do not give to renal patients