Mixing vitamins and prescription meds for weight loss

Dear Ask The Doctor:I was prescribed phentermine, can i take tonalin with it?

Dear Ebony: While tonalin at recommended doses are safe for most, it's reaction with other drugs including phentermine has not been studied yet. Tonalin may cause symptoms of upset stomach, nausea, diarrhea, heartburn, indigestion and fatigue in some users. I would suggest that you consult your doctor or pharmacist before taking these two together.