When i was taking perindopril unicorn my blood pressure was on a normal level my weight was controllable now the pharmacist changed my medication to prexum and i see so many changes in my body, im gaining weight my feet are always swollen ?

Edema: Prexum and perindopril are the same molecule and are ACE inhibitors. Edema isn't a usual side effect unless you have associated kidney or liver disease or congestive heart failure. Are you also taking a validator like amlodopine which can cause swelling of the feet? Is your thyroid underactive? Discuss these with your MD when you notify him\her of your weight gain and edema.