Effect of Sublingual Formulation of Dexmedetomidine HCl (BXCL501) - Alcohol Interaction 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 1, double-blind, placebo-controlled, within subjects study. This study will consist of 3 laboratory test sessions following pretreatment with BXCL501/placebo for 10 heavy drinker participants with comorbid PTSD. Participants (n=10) will participate in a laboratory study with 3 test days (minimum of 2 days, but no longer than 2 weeks between each test session); for each test day they will be assigned to receive sublingual BXCL501 40µg, 80µg and placebo in a randomized fashion. Test sessions will be conducted to evaluate stress (PTSD) reactivity and alcohol cue reactivity. Participants will also receive IV ethanol administered via "clamp methodology" to assess for the effects of BXCL501 in combination with ethanol. Since this is the first time BXCL501 is being tested in combination with alcohol administration, the study team will be using a modified randomization where participants will not receive the 80µg dose until they have received the 40µg dose.