SMZ-TMP, substituted for Bactrim ds

My doctor has prescribed SMA-TMP (sulpha?) for a possible infection.  My PSA has risen & the doctor has thought it might be caused by an infection.  My question - is it possible to drink alcohol while taking this medication?  By drinking, I mean I would be only drinking 3 or 4 beers one night during the 10 day period of taking the medication.