Mechanisms of lipid-lowering agents.
Lipid-lowering agents are used with the purpose of ameliorating hyperlipoproteinemias, in order to prevent arterial disease. Lipid-lowering drugs can be classified into absorbable agents and into nonabsorbable compounds, acting within the gastrointestinal lumen. Absorbable drugs (fibric acids, nicotinic acid, probucol, HMG-CoA reductase inhibitors) reduce plasma very-low-density lipoproteins (VLDL) and/or low-density lipoproteins (LDL) by a variety of mechanisms. Fibric acids, in particular, act by stimulating the catabolism of VLDL and also, as a consequence, improving LDL delipidation, thus favoring receptor uptake. Nicotinic acid and acipimox interfere with the biosynthesis of LDL and can also improve the clearance of VLDL/LDL. Probucol acts by a newly described mechanism, i.e. accelerating reverse transport of cholesteryl esters from high-density lipoproteins to lower-density lipoproteins. Finally, HMG-CoA reductase inhibitors, interfering with the biosynthesis of cholesterol, can induce an increased expression of liver high-affinity lipoprotein receptors. Nonabsorbable agents (anion-exchange resins, neomycin, beta-sitosterol) interrupt the recirculation of bile acids and/or reduce the absorption of cholesterol with the gut. They display a selective activity on hypercholesterolemia, again by increasing LDL receptor expression. The choice of one or more lipid-lowering agents will depend upon the patient's phenotype, determining responsiveness to the pharmacological treatment.
Sirtori
C R
CR
Institute of Pharmacological Sciences, University of Milan, Italy.
Manzoni
C
C
Lovati
M R
MR
D006801:Humans; D006951:Hyperlipoproteinemias / Q000188:drug therapy*; D000960:Hypolipidemic Agents / Q000494:pharmacology / Q000627:therapeutic use; D007408:Intestinal Absorption / Q000187:drug effects; D008074:Lipoproteins / Q000378:metabolism
D000960:Hypolipidemic Agents; D008074:Lipoproteins