I found a Finnish study (made by FInnish psychiatrist Sami Anttila) on interactions.

Venlafaxine (Effexor) metabolizes mainly through CYP2D6.
Using citalopram (or sertraline, fluoxetine or paroxetine) with it may block the reuptake of noradrenaline.

From what I saw in this study, most antidepressants don't need the CYP-450 enzyme to metabolize. A lot of people use clonazepam or some other tranquilizer especially when starting an antidepressant and maybe even after it and it's ok. Your pdoc won't have a problem choosing an antidepressant for you

Here's the study for proof though it won't make any sense if you don't know FInnish. but anywhoozle.
http://www.samianttila.net/interakti...kkeiden_yhtei/

Let us know how your meeting with pdoc went.