Intra-nasal vs. Intra-venous Ketamine Administration

This randomised, quadruple-blind, parallel-group trial compares intranasal ketamine (50 mg, delivered as five alternating-nostril doses) with IV ketamine (0.2 mg/kg IV push) in patients with Major Depressive Disorder and MADRS >20.

Patients failing to achieve response in the parallel phase may be offered an additional course of up to four 0.5 mg/kg ketamine infusions given twice weekly over two weeks (40-minute infusions). Primary outcome assessments include MADRS change; safety and tolerability monitored.