I Am Overweight /obese? (5 Ft. Even & 210 Lbs.)

I am overweight /obese? (5 ft. even & 210 lbs.) about a year ago, my old Dr. Prescribed Quismia but it was too expensive & medi-cal refused to cover it so he re-ordered me phentermine & topirimate ("supposedly" the active ingredients in Quismia... Or so he said)
Anyway, I still have about 6 wks worth left but as I was switched to a "health care plan" I can no longer be treated by my Dr. (I had hi, for over 10 years too!)
So I don't know if these pills are still potent. I know that some of them say they're close to the expiration date, but will they still work if I continue to take them. (They're an older prescription that Dr. D increased after I had been on them for awhile. The Quismia recommended an increase every so often, so Dr. D increased my generic meds on the same timeline) . .. EXAMPLE: take 6 mg. for 26 wks, then increase to 11mg. but I kept the lower dose pills because they're so expensive.)