Fibric acid derivatives

Fibric acid derivatives

Fibric acid is produced by several fungi. Two derivatives of thisacid are fenofibrate and gemfibrozil. These drugs are used to re-duce high triglyceride levels and, to a lesser extent, high LDL lev-els.

Pharmacokinetics

Fenofibrate and gemfibrozil are absorbed readily from the GI tract and are highly protein-bound. Fenofibrate is hy-drolyzed while gemfibrozil undergoes extensive metabo-lism in the liver. Both drugs are excreted in the urine.

Pharmacodynamics

Although the exact mechanism of action for these drugs isn’t known, researchers believe that fibric acid derivatives may:

·                 reduce cholesterol production early in its formation

·                 mobilize cholesterol from the tissues

·                 increase cholesterol excretion

·                 decrease synthesis and secretion of lipoproteins

·                 decrease synthesis of triglycerides.

Power in the blood

Gemfibrozil produces two other effects:

·                 It increases high-density lipoprotein (HDL) levels in the blood (remember, this is “good” cholesterol).

·                 It increases the serum’s capacity to dissolve additional choles-terol.

Pharmacotherapeutics

Fibric acid drugs are used primarily to reduce triglyceride levels, especially very-low-density triglycerides, and secondarily to re-duce blood cholesterol levels. They’re typically used to treat pa-tients with types II, III, IV, and mild type V hyperlipoproteinemia.

Drug interactions

Fibric acid drugs may displace acidic drugs, such as barbitu-rates, phenytoin, thyroid derivatives, and cardiac glycosides.

·                 The risk of bleeding increases when fibric acid derivatives are taken with oral anticoagulants.

·                 Fibric acid derivatives can lead to adverse GI effects.

·                 The hypoglycemic effects of repaglinide may be increased and prolonged if taken with gemfibrozil.

·                 Use of fibric acid derivatives and HMG-CoA reductase inhibitors may increase the risk of rhabdomyolysis.