Hot on the heels of similar news about sister drug rosiglitazone (brand name Avandia; reported here in the story ”Diabetes Drug Linked to Fracture Risk”), the Type 2 diabetes drug pioglitazone (Actos) has been linked to increased risk of certain kinds of bone fractures in women.
Pioglitazone and rosiglitazone are both members of the drug class known as thiazolidinediones. These drugs prompt the body’s tissues to use insulin more effectively and the liver to produce less glucose.
Last week, the U.S. Food and Drug Administration (FDA) and pioglitazone manufacturer Takeda Pharmaceuticals North America, Inc., released a letter alerting health-care professionals and consumers that increased reports of fractures had been found in women who take the drug. The warning was based on an analysis of data from multiple clinical trials in Takeda’s database. The trials, which included more than 15,000 participants, compared drug therapy with pioglitazone to therapy with either another diabetes drug or a placebo. While they were not designed to study pioglitazone’s effect on bone, the trials did record “adverse events,” such as fractures.
The analysis of data from these trials showed that women who took pioglitazone were more likely to experience fractures of the forearm, hand, wrist, foot, ankle, or leg—but not of the hip or spine, sites usually associated with postmenopausal osteoporosis (degenerative bone disease). Men who took pioglitazone did not experience any increased risk of fractures.
Until more research can be done on the effect of thiazolidinediones on fracture risk, the mechanism by which they are associated with increased fracture rates in women will remain unclear. In the meantime, the FDA and the drugs’ manufacturers encourage health-care providers to consider the risk of fracture when choosing to begin or continue drug therapy with pioglitazone or rosiglitazone in women.