Perna has a good point. I believe you can get something similar to a DUI (maybe with a different name) if you're driving on medications - even those prescribed to you - and you are driving erratically or not in the shape you should be to be driving. So regardless of the fact that your friend is LYING - if she really was on that much medication plus the alcohol (which should not be combined with medication ANYWAYS) then she shouldn't have been driving, period.

I don't drive at night after I've taken my meds. It's too dangerous.