IV ketamine's rapid antidepressant and anti-suicidal effects make it well suited to the inpatient timeline, where the 6–8-week lag of standard antidepressants is often untenable. This sheet reviews dosing, monitoring, patient selection, and safety considerations for using subanesthetic ketamine on a psychiatric unit.

Rationale and Evidence Base

• The landmark 2000 trial established ketamine's rapid antidepressant effect (Berman RM et al, Biol Psychiatry 2000;47(4):351–354).
• A single dose has been shown to markedly reduce suicidal ideation within 24 hours; improvement was maintained during a 6-week follow-up with optimized standard treatment (Grunebaum MF et al, Am J Psychiatry 2018; 175(4):327–335).
• The APA's consensus statement (Sanacora G et al, JAMA Psychiatry 2017;74(4):399–405) offers guidance on safe, responsible use and can help make the case to hospital leadership.
• IV ketamine remains off-label for depression; intranasal esketamine is FDA approved.

Administration Protocol

• The most commonly studied regimen is 0.5 mg/kg infused over 40 minutes. This is a subanesthetic dose.
• Typical course: twice-weekly infusions for up to 2 weeks while hospitalized. If no improvement after about 4 doses, consider pivoting — most commonly to ECT.
• Advantages over intranasal esketamine: weight-based titration, rapid offset if an adverse reaction occurs, and substantially lower cost (ketamine is off-patent).
• Anesthesiology need not be routinely involved for subanesthetic dosing per APA guidance, though co-review during program launch/credentialing is reasonable. Staffing: one physician plus one nurse to administer the infusion and monitor vitals.