I would imagine the risk there would be extremely low to the point of being irrelevant.
I would also suggest spacing your drinks out to maybe one unit every hour or so and a maximum of three drinks? Maybe tell your mates you're taking some medication and can't get drunk? They don't need to know what it is.
I would be mindful of having a 'reaction' to both chemicals in your system which might freak you out, on top of being abroad without your partner. If you start to feel weird or dizzy, that might really spike the chances of having a bad panic attack, it would for me anyway! To be honest you'll probably be ok if you take a small dose at 5am then drink later than evening...if you keep the volume of alcohol low. I would just prefer to err on the side of caution. And make sure you eat loads during the day!
Kudos for going too, I'm sure you'll be fine.