Don't do it. I took a 7.5mg pill on the plane yesterday after a small can of beer and a tiny shot of red wine. I drifted off but woke up shortly afterwards with the most intense nausea and difficulty breathing alongside aching difficult in moving. I seriously felt as if I was dying.
The air stewardess looked particularly concerned at my condition and was repeatedly bringing me cold tissues to put on my face. The instructions say don't mix with alcohol -- it's best to stick to that advice.