http://www.erowid.org/plants/mushrooms/mushrooms.shtml
Taking psyilocybin containing mushrooms while on an MAOI can dramatically increase the effects of the experience. MAOIs are most commonly found in the prescription anti-depressants Nardil (phenelzine), Parnate (tranylcypromine), Marplan (isocarboxazid), Eldepryl (l-deprenyl), and Aurorex or Manerix (moclobemide). Ayahuasca also contains MAOIs (harmine and harmaline). Check with your doctor if you are not sure whether your prescription medication is an MAOI.
Thats from erowid. I have no idea what type of drug it is your taking, but prescription stuff and heavy hullucinogenics generally arnt a good combo
Edit: I'd like to point out that magic mushrooms give you the high via their poison, so be careful with that too. Not to say that they're not fun though.