Just remember Tussionex already contains an anti-histamine of its own, chlorpheniramine, so the promethazine will just add to the anti-histamine effect, and the other shared effects such as the anti-chollergnic effects. Adding promethzine for next time is not necessary for Tussionex enjoyment. I would not combine alcohol with an opiate and two sedating anti-histamines, myself, as it is dangerous - even at the doses you are talking about, potentially.