Which significant risk is associated with Actos as indicated by a black box warning?

Actos, or pioglitazone, is associated with a black box warning primarily concerning the risk of fluid retention, which can exacerbate congestive heart failure (CHF). This warning is significant because fluid retention can lead to serious outcomes in individuals with heart conditions, resulting in worsening heart failure or even hospitalization.

The connection between Actos and fluid retention arises from its mechanism as a thiazolidinedione medication, which works by increasing insulin sensitivity but also has effects on fluid balance. This risk requires careful monitoring in patients who have a history of heart failure or are at risk for developing it. Adopting proper risk management strategies, such as close evaluation of heart function before and during treatment with Actos, is essential for patient safety.

Other options, while they may present risks in different contexts or medications, do not carry the same level of concern as indicated by a black box warning specifically related to Actos.