Effect of Sublingual Formulation of Dexmedetomidine Hydrochloride (HCl) (BXCL501) - Outpatient Study

BXCL501 is a sublingual film containing dexmedetomidine. Dexmedetomidine is an alpha-2 adrenergic receptor agonist and has higher intrinsic activity and is more potent in vitro than either clonidine or lofexidine. The drug has a high free brain to free plasma ratio after dosing in rats that persists after plasma concentrations are cleared. Dexmedetomidine does not depress respiratory function. It is not predicted to have abuse potential. BXCL501 will bypass 1st pass metabolism and produce fewer problems in participants with compromised liver function. This laboratory study is a phase 1b, open label, single arm safety study which is a follow-up to the Effect of Sublingual formulation of Dexmedetomidine HCl (BXCL501) on Ethanol in Heavy Drinkers with PTSD - Alcohol Interaction Study Previously conducted. Participants will be heavy drinkers with comorbid PTSD (or no diagnosis of PTSD but have experienced at least one qualifying Criterion A traumatic event). For the study at least 10 completers will participate in an outpatient study. Participants will receive BXCL501 for 28 days. Participants will receive 40µg on days 1-2. On days 3 and 4, participants will receive 40µg twice per day. On days 5 and 6 participants will receive 40µg in the morning and 80µg in the evening. If dosing is tolerated, per clinical judgement, participants will begin to receive 80µg twice per day on days 7-28. Participants will be seen in the clinic on days 1, 5 (+/- 2 days), and during weeks 1, 2, 3, and 4 with the study nurse and/or research staff to assess side effects as well as drinking, PTSD symptoms, cognitive function, memory, sleep and mood.