Zolpidem suppresses cortical spreading depolarization and protects against ischemia/reperfusion injury and resulting neurological dysfunctions

Building on clinical reports of symptomatic improvement in stroke patients following zolpidem administration, we investigated its neuroprotective efficacy and underlying mechanisms in a preclinical model of ischemia/reperfusion (I/R) injury. Pharmacokinetic analyses revealed that zolpidem preferentially accumulates in the hypothalamus and frontal cortex, with a notably prolonged half-life in the hypothalamus, suggesting region-specific drug retention. Early post-reperfusion administration of zolpidem (within 1.5 h) significantly reduced infarct volume, lowered glutamate levels, and improved motor recovery, underscoring a critical therapeutic window for intervention. Mechanistically, zolpidem enhanced phasic GABAergic signaling via α1 GABA-A receptors, reduced NKCC1 mRNA expression, and maintained neurochemical homeostasis without altering GABA transporter or receptor protein levels. Notably, zolpidem suppressed the frequency of cortical spreading depolarizations (CSDs), key propagators of secondary neuronal injury, without affecting wave dynamics, and modulated neurovascular coupling. Ischemic stroke outcomes are worsened by CSDs - waves of neuronal depolarization that propagate through compromised brain tissue and exacerbate secondary damage. These findings position zolpidem as a promising candidate for drug repurposing in stroke, uniquely targeting both early neuroprotection and longer-term functional recovery through selective modulation of GABAergic signaling and CSD suppression. Future clinical trials are warranted to define optimal therapeutic timing and maximize clinical benefit.