Dexmedetomidine Nasal Spray for the Treatment of Panic Attacks in Adults

Inclusion Criteria: 1. Written informed consent is provided after full explanation of objectives, procedures, potential benefits, and risks, with agreement to comply with study requirements. 2. Age between 18 and 65 years at screening. 3. Meet the DSM-5 diagnostic criteria for panic attacks (PA), including but not limited to those occurring in the context of post-traumatic stress disorder, acute stress disorder, generalized anxiety disorder, or social anxiety disorder. At baseline, a Clinical Global Impression-Severity of Illness (CGI-SI) score ≥ 4 is required. 4. Experience an average of ≥2 panic attacks daily during the week preceding enrollment. Exclusion Criteria: 1. History of panic attacks induced by other psychoactive substances; or prior history of substance abuse involving psychiatric or anesthetic drugs. 2. Use of benzodiazepines, 5-HT1A receptor agonists, or other anxiolytics within 4 hours before enrollment. 3. General anesthesia within the past 28 days. 4. Known hypersensitivity to dexmedetomidine or any component of the investigational product. 5. Myocardial infarction or unstable angina within 6 months; heart rate \<60 bpm at screening; history of severe arrhythmias (e.g., Type II second-degree or higher atrioventricular block) or cardiac insufficiency. 6. History of ischemic stroke or transient ischemic attack; uncontrolled hypertension (SBP ≥ 180 mmHg and/or DBP ≥ 110 mmHg) or hypotension (SBP \< 90 mmHg and/or DBP ≤ 50 mmHg) despite treatment. 7. Coagulation abnormalities: PT \> ULN + 3 s and/or APTT \> ULN + 10 s. 8. Significant airway obstruction (e.g., obstructive sleep apnea syndrome, asthma); or use of α2-adrenergic receptor agonists/antagonists within 14 days. 9. Abnormal liver function (ALT/AST \>2×ULN or total bilirubin \>1.5×ULN) or renal dysfunction (serum creatinine \>1.5×ULN). 10. History of cognitive impairment or epilepsy. 11. Pregnant or breastfeeding; or women of childbearing potential unwilling/unable to use effective contraception from 30 days before screening through 6 months after study completion. 12. Any other condition deemed unsuitable by the investigator.