Which lipid-lowering agent is not suitable for patients with severe renal impairment?

Fibrates, such as fenofibrate and gemfibrozil, are not suitable for patients with severe renal impairment due to their potential to cause adverse effects, including increased risk of myopathy and rhabdomyolysis. These agents are primarily excreted by the kidneys, so compromised renal function can lead to increased serum levels and a higher risk of toxicities.

In contrast, statins are generally considered safe for use in patients with mild to moderate renal impairment, although doses may be adjusted. Ezetimibe is also not contraindicated in patients with renal issues, as it is primarily metabolized in the liver. Omega-3 fatty acids are usually well tolerated and can be used in those with renal impairment, provided that other health considerations are taken into account. Thus, fibrates are specifically highlighted due to their significant association with renal function and the risks involved in their use in patients with severe renal compromise.