I always aproachedapproached the precepts as very important guidelines but not very important bansrather than rigid rules for banning one's actions.
Certainly, while on the eightfold path, if one intakes a substance that even subtlety clouds the mind then it willthat substance would lead to one's suffering and the suffering of those around one. The more one understands this and the more one sees things as they are, the more one will follow the presepts naturally like a river follows the best way down the side of a mountain.-Metta