Hi my doc had me on pioglitazone as a replacement for a glicazide which was giving me hypos. My sugars were still high after a few months and i was also put on sitagliptin. I was actively trying to lose weight but would lose a few pounds and they it would come back on. I read all the info about the bladder cancer risks but, to be honest, what stopped me taking these was the info that it made you gain/keep weight on. I came off it a few months ago and have lost about 24lbs. My blood sugar has also come down, mainly due to the weight loss.
If you do not have an issue with weight, these pills are ok - I didn't suffer with any side effects and the potential side effects from alternatives such as sitagliptin are comparatively much worse.
You don't say why your doc wants to increase your meds - is your sugar going up? I would try and avoid increasing your meds if you can as docs do seem to treat it as a given that you will progress through meds (see above!).
My doc tried to get me to go back on the pioglitazone even tho weight and sugar had gone down. Go figure.
Good luck!