Both rosiglitazone and pioglitazone are members of the thiazolidinedione (TZD) chemical class, and are associated with various side effects, including weight gain, fluid retention and oedema ...

Do not double the dose. Q : Can Pioglitazone cause weight gain? Pioglitazone commonly causes weight gain which may be dose-related. The reason for this weight gain could be fat accumulation.