Ketamine
Ketalar · Ketaset
NMDA Receptor AntagonistSchedule IIIGeneric available
Ketamine Hydrochloride Injection, a racemic mixture of ketamine, is a non-selective, non-competitive antagonist of the N-methyl-D-aspartate (NMDA) receptor, an ionotropic glutamate receptor. The major circulating metabolite of ketamine (norketamine) demonstrated activity at the same receptor with less affinity. Norketamine is about 1/3 as active as ketamine in reducing halothane requirements (MAC) of the rat.
Compare Ketamine →FDA-Approved Indications
- General anesthesia — sole agent for procedures not needing muscle relaxation
- Anesthesia induction (adjunct to other agents)
- Anesthesia supplement (adjunct to other agents)
Common Off-Label Uses
- Treatment-resistant depression
- Acute suicidality
- Chronic pain
- Status epilepticus (refractory)
What Sets This Drug Apart
- FDA-approved for anesthesia only; all psychiatric use (TRD, suicidal ideation) is off-label via IV infusion or compounded formulations
- IV ketamine (0.5 mg/kg over 40 min) shows rapid antidepressant response in TRD, typically within hours; effects are transient (days) requiring serial infusions
- Racemic mixture (R- and S-enantiomers); compared to esketamine, IV racemic ketamine may have different efficacy/tolerability balance
- No REMS requirement for IV ketamine (unlike esketamine), but responsible practice requires supervised clinical settings
- Schedule III; abuse and diversion potential present; not suitable for unsupervised home use in current practice standards