There should be no interaction.
And 1 gm is shooting way to high; you won't need nearly that much material. Please read Foreigner and Jamshyd's (and to some extent, my) dosing regimen more closely. You're trying to maintain a threshold dose over a period, not get 'fucked up'.
Right, but you'll be dosing more and more infrequently over the course of the week. I would advise you to stop when you seem completely tolerant to what was once a threshold dose, and IME, this occurs before the 1 wk. mark.
I'd say that the risk is obscuring the anti-depressant effect with mental fogginess, but the risk is relatively minor. Heh, the main risk might be wasting ketamine.