Randomized, parallel-group Phase II study (n=40) comparing nitroprusside versus placebo co-administration with ketamine (0.5 mg/kg IV over 40 minutes) in patients with major depression to assess antidepressant and psychotomimetic effects.
This randomized, triple-blind, parallel Phase II trial tests whether sodium nitroprusside alters the antidepressant efficacy or reduces the psychotomimetic effects of ketamine in patients with major depression.
Nitroprusside is administered as a 0.5 µg/kg/min IV infusion over 240 minutes with ketamine 0.5 mg/kg IV given during the final 40 minutes; outcomes include MADRS for mood, CADSS for psychotomimetic effects, and serial blood biomarkers to explore mechanisms.
Placebo saline infusion with ketamine infusion (placebo comparator).
Saline placebo infusion over 240 minutes (placebo), ketamine 0.5 mg/kg IV over last 40 minutes.
Ketamine IV infusion over 40 minutes starting at minute 200 of the 240-minute session.
Nitroprusside infusion with overlapping ketamine infusion (experimental).
Ketamine IV infusion over 40 minutes given during final 40 minutes of nitroprusside infusion.
Sodium nitroprusside infusion 0.5 µg/kg/min over 240 minutes; recorded as active comparator (encoded as placebo compound reference).