Advances in drug treatment of dyslipidemia: focus on atorvastatin

The focus of lipid-lowering therapy with drugs is prevention of complications of atherosclerosis. Landmark clinical trials have demonstrated that lowering low density lipoprotein cholesterol (LDL-C) may not only reduce coronary artery disease (CAD) risk but also may slow the progression and even induce regression of atherosclerosis in the coronary arteries. In addition, much attention has been given in recent years to the importance of triglyceride-rich lipoprotein (TRL) as a CAD risk factor, and the benefit of reducing plasma triglyceride levels and raising high density lipoprotein cholesterol (HDL-C) levels to prevent the recurrence of coronary events. Lipid-lowering drugs should be used within the framework of a systematic approach to treatment. Consideration must be given to the lipoprotein abnormality, the severity of disease, the role of combination therapy, and the spectrum of action of the drug and its pleiotropic effects (ie, effects beyond the expected action on lipoproteins). Five major agents have been used for the treatment of dyslipidemias. Three (resins, probucol and statins) target LDL-C, and two (fibrates and niacin) target primarily TRL and HDL-C. Fibrates and statins are the drugs of choice. Fibrates correct many abnormalities of lipoprotein metabolism in addition to having beneficial pleiotropic effects such as reducing fibrinogen and plasma viscosity. They inhibit the transcription of apolipoprotein (apo) CIII and enhance that of apoAI and lipoprotein lipase. Statins are safe and potent drugs for reducing LDL-C levels, and their efficacy in primary and secondary prevention of CAD has been amply demonstrated. They share a modes effect of raising HDL-C levels. Their pleiotropic effects, which include improvement of endothelial dysfunction, are numerous and may contribute to their spectacular beneficial effect of reducing CAD risk. They have effects that are complementary to those of fibrates, but the two drugs should be combined with caution because of the danger of myopathy. Atorvastatin is a major addition to this class of drugs because of its high efficacy and large spectrum of action. It lowers LDL-C levels effectively, not only in patients with severe forms of hypercholesterolemia but also in those with homozygous familial hypercholesterolemia. The effect of atorvastatin on LDL-C may be further enhanced by combining it with a resin. The ability of atorvastatin to lower triglyceride levels as well as LDL-C levels indicates that combined hyperlipidemia, a condition that, in the past, was best controlled with combination therapy, can now be treated with a single drug. It is also effective in patients with isolated hypertriglyceridemia and, although less potent than fenofibrate at reducing TRL and increasing HDL-C, it has a greater impact on the atherogenic risk ratios such as LDL-C:HDL-C. The profile of its pleiotropic effects is promising.