Ketamine

Background

• Phencyclidine (PCP) derivative
• Inhibits NMDA (N-methyl-d-aspartate) receptors
• Dose-dependent effects: low doses are primarily analgesic, while high doses cause dissociative anesthesia
  • When used for management of acute pain, can be opioid-sparing

Dosing

• Analgesia1
  • Intermittent: start at 0.1 mg/kg IV q4h, and titrate (max 0.35 mg/kg)
  • Continuous infusion: start at 0.1 mg/kg/h IV infusion, and titrate (max 0.25 mg/kg/h)
• Dissociative anesthesia: ≥1 mg/kg

Hepatic Dosing

• Avoid in liver dysfunction

Safety

• Avoid in patients with psychosis, severe cardiovascular disease, or liver dysfunction

Adverse Effects

• Primarily dose-dependent, with nausea, vomiting, vivid dreams, hallucinations, and dissociation seen at high doses

Pregnancy

• Unclear safety in pregnancy