namasthe doctor i varalakshmi age 60 iget zita met 50/1000 morning 1 night 1takeing, this tablet is good or bad ,last 2months ihave taken this tab. 2months back obimet 1000 taken, this tablet is not working my doctor priscribed istamet ,this tab is very cost, because itaken zitamet 50/1000mg .please give your advice which is better.