Good Evening. I Have Been On Effextor HCL EX 150

Good evening. I have been on Effextor HCL EX 150 MG and just about a week ago decreased down to 75 mg. 1 cap daily. I have been severely sick and the dr told me that to help my cough I could take Robitussin. I always Ck myself cause of my RX. It specifically states DO NOT USE if taking a MAOI. Now I have to ask..... Is it safe for me to take this???