Key Takeaways
Extended Takeaways
- Symptom trajectories diverged over maintenance despite similar baseline severity: at year 1, mean QIDS-SR was 7.6 (95% CI, 5.7–9.6) with IV-KET versus 11.7 (95% CI, 9.3–14.0) with IN-ESKET (P = .01).
- In this cohort, the longest maintenance cycle lasted a median of 61 weeks with IV-KET and 48 weeks with IN-ESKET, with median treatment counts of 14 and 28, respectively, which may help frame follow-up burden when counseling patients.
- Maintenance eligibility in this clinic required at least a partial response, defined as more than 25% reduction in QIDS from baseline, or clinically significant subjective improvement; clinicians then tapered from 4 weekly treatments toward every 2 weeks, then every 3, 4, and 5 to 6 weeks as symptoms allowed.
- Acute cardiopulmonary tolerability was similar overall: the probability of SpO2 < 92% was 0.007 for IV and 0.003 for IN (P = .25), and both treatments showed relatively stable systolic blood pressure trajectories over time.
- Pulse changes differed modestly at baseline maintenance phase, with mean change in pulse of 4.4 for IV-KET and 5.9 for IN-ESKET (ratio = 0.74; 95% CI, 0.58–0.96; P = .02), suggesting no emerging physiologic burden favoring more intensive vital-sign concern with IV-KET in this analysis.
- Three patients attempted suicide while on IV-KET during maintenance, including 2 with prior suicide attempts, underscoring that ongoing suicide risk assessment remains necessary even in patients who have shown antidepressant benefit.
