Are you still suffering from headaches, dizziness, or nausea? If so, I wouldn't drink or smoke. My buddy has has quite a few concussions and he still drinks and smokes weed, but he usually waits a few days after the concussion until he's feeling better.

Just my opinion, but don't smoke or do drugs anyways, it's not good for you, adn it will have negative affects on you sexually. Alcohol will too, but they're not as great. If you have the will-power to, don't drink either.