Powell WR, et al. - In this retrospective cohort study of 145,250 people with type 2 diabetes mellitus, researchers analyzed the risks of all-cause mortality and cardiovascular events related to adding vs switching to second-line therapies. Compared with thiazolidinedione therapy, second-line use of sulfonylureas was related to higher mortality and cardiovascular risks. The study findings might inform decisions on whether to augment or discontinue metformin. Switching to a sulfonylurea seems unfavorable vs other therapies when considering the long-term risks. They found that adding a thiazolidinedione to existing metformin therapy seems to be superior to adding or switching to a sulfonylurea.