Open‑label, single‑arm Phase II proof‑of‑concept study (n=20) evaluating intranasal ketamine spray (sub‑anesthetic doses, product up to 75 mg) for acute treatment of chronic cluster headache in adults.
This single‑site Danish open pilot study assessed whether intranasal ketamine hydrochloride spray administered at sub‑anesthetic doses reduces acute pain in adults with chronic cluster headache (n=20).
Primary endpoint was ≥50% reduction in pain on a 0–10 NRS at 15 minutes after administration; secondary endpoints included pain at 30 minutes, proportion achieving NRS <4, need for rescue medication, patient preference versus oxygen or injectable sumatriptan, and serious adverse events.
Intranasal ketamine spray administered in sub‑anesthetic doses for acute treatment of chronic cluster headache (single‑arm, open‑label).
Intranasal spray (ketamine hydrochloride); product concentration reported up to 75 mg; administered as single sub‑anesthetic dose for acute CH attack; exact per‑dose regimen per protocol.