I don't know how he could've been taking both Phenergan and Ambien and been functioning at all, unless he's built up tolerance. I've taken both- separately, not together, and not with alcohol- on rare occasions, and can't stay vertical. In fact I got very drunk on Ambien once (didn't get right into bed after taking it) and couldn't sucessfully navigate my way from my bathroom to my bedroom. Both together would probably put me to sleep permanently.