Its pharmacokinetic properties make ketamine an attractive agent for use in the critical care setting (Table 1). Depending on the route of administration, ketamine typically exhibits a rapid onset of action.[1,5,10] It undergoes clearance via cytochrome P450-mediated mechanisms (CYP 2B6, 2C9, 3A4), which can be altered in the setting of hepatic impairment and interacting medications. In the general population, the elimination half-life is approximately 2–3 hours. Once metabolized hepatically via N-dealkylation, norketamine can be 33% as potent as the parent compound, leading to potential prolonged clinical effects. Ketamine is lipophilic with limited protein binding, allowing for easier distribution into the CNS.
Crit Care Med. 2020;48(6):899-911. © 2020 Lippincott Williams & Wilkins