Which antidiabetic drug class is inappropriate in heart failure due to risk of fluid retention?

• A. Thiazolidinediones
• B. Metformin
• C. Sulfonylureas
• D. DPP-4 inhibitors

Answer: (A)

Fluid retention is a key adverse effect of thiazolidinediones. These drugs activate PPAR-γ to improve insulin sensitivity, but they increase renal sodium reabsorption and expand extracellular fluid, leading to edema. In heart failure, this extra fluid can worsen symptoms and trigger decompensation, so this class is considered inappropriate for patients with HF.

That’s why the Beers Criteria flags thiazolidinediones in people with heart failure due to the edema risk. The other options don’t carry edema as a primary concern to the same extent, so they’re generally favored in HF management, though each has its own considerations (for example, metformin considerations with renal function or acute HF, and DPP-4 inhibitors with variable cardiovascular profiles).