I am sure that you have already resolved this issue, but for your sake you should do a little research on mediciations. The medical community knows an alarmingly small amount about psychopharmacology. Just to give you an idea of how little the medical community knows google the Mechanism of Action (MoA) of acetamynaphin (tylenol). Mechanism of Aciton is the medical term that means what makes it work. Better to be safe than sorry.
Depending on the drug, it would be as bad as alcohol, in my opinion. Being one who has undergone back surgery and pain meds, I know I should not be behind the wheel of a vehicle and I sure would not want to carry hot and me being loaded.