Phentermine & Fluoxetine?

Actually I see a Dr. that gives me both, apparently theres something about taking the two together, I can't remember exactly what. I'm on 15mg of phentermine twice a day and 30mg of prozac once a day, no problems here. My drs name is Dr. Harrison Willcuts, in west spfld. ,MA. he went to Harvard and is/was a surgeon, he's retired from that now, he's about 80 yrs. old. Hope this helps.