Many won't like this....and its against my normal MO, however.... I have to say that it's best to shy away from any drug use during play. Alcohol, or otherwise...
You see, our instincts are extremely valuable, irreplaceable really. When influenced by an outside substance, your instincts are muted and become difficult to receive...
To take it seriously and to attempt to make a living with poker, one must not use outside substances. If you're simply playing for the entertainment of the game and can afford to lose what your playing with, it really doesn't matter... Play on.