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Treatment of heterozygous familial hypercholesterolemia with lipid-lowering drugs
1Department of Medicine, Oregon Health Sciences University, Portland 97201.
Insights
Patients with familial hypercholesterolemia (FH) benefit from hypolipidemic therapy to prevent early coronary artery disease (CAD). Combination therapy, particularly with HMG CoA reductase inhibitors, offers the most significant LDL cholesterol reduction.
Area of Science:
- Cardiology
- Pharmacology
- Genetics
Background:
- Familial hypercholesterolemia (FH) patients face high risk of premature coronary artery disease (CAD).
- Elevated low-density lipoprotein (LDL) cholesterol is a key risk factor in FH.
- Hypolipidemic therapy is crucial for managing FH and preventing cardiovascular events.
Purpose of the Study:
- To review the efficacy of various hypolipidemic drugs and drug combinations in lowering LDL cholesterol in patients with heterozygous FH.
- To identify the most effective therapeutic strategies for managing hypercholesterolemia in this high-risk population.
Main Methods:
- Review of clinical trials and pharmacological data on hypolipidemic agents.
- Comparison of LDL cholesterol reduction percentages for single-agent and combination therapies.
- Evaluation of drugs targeting cholesterol biosynthesis (HMG CoA reductase inhibitors) and other mechanisms.
Main Results:
- Single agents like bile-acid sequestrants and nicotinic acid achieve 20-35% LDL reduction.
- HMG CoA reductase inhibitors (lovastatin, simvastatin, pravastatin) lower LDL by 30-50%.
- Combination therapy, especially HMG CoA reductase inhibitors with bile-acid sequestrants or nicotinic acid, yields the greatest LDL reduction (45-60%).
Conclusions:
- Currently available hypocholesterolemic drugs can significantly alter the natural history of premature atherosclerosis in FH patients.
- Combination therapy, particularly involving HMG CoA reductase inhibitors, represents the most promising approach for aggressive LDL cholesterol lowering in heterozygous FH.
Abstract:
Patients with heterozygous familial hypercholesterolemia (FH) constitute a unique population at high risk for the premature development of coronary artery disease (CAD) and in whom long-term hypocholesterolemic therapy to reduce elevated levels of low density lipoprotein (LDL) cholesterol is most clearly indicated. Optimal therapy invariably requires diet regulation plus hypolipidemic drug therapy. When used as single agents, the bile-acid sequestrants, cholestyramine and colestipol, lower LDL cholesterol concentrations by 20% to 35% in compliant patients, whereas decreases of 20% to 30% can be achieved with nicotinic acid in doses of 3 to 6 g/day. Bezafibrate, fenofibrate, and ciprofibrate have also been shown to lower LDL cholesterol levels by 20% to 30%, and these drugs are more effective than gemfibrozil and clofibrate. Probucol, neomycin, and D-thyroxine reduce LDL cholesterol concentrations by 10% to 15% in single-drug use. Clinical trials with a new class of drugs that inhibit the rate-limiting enzyme in cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, and that includes lovastatin, simvastatin, and pravastatin indicate that these drugs lower LDL cholesterol concentrations by 30% to 50% in patients with heterozygous FH. Combined drug therapy with a bile-acid sequestrant and nicotinic acid lowers LDL cholesterol by 40% to 55%, whereas fenofibrate, bezafibrate, or probucol plus a bile-acid sequestrant results in reductions varying from 25% to 50%. The combinations of an HMG CoA reductase inhibitor with either a bile-acid sequestrant or nicotinic acid appears to be the most promising, and these regimens reduce LDL cholesterol levels by 45% to 60%. With appropriate use, the currently available hypocholesterolemic drugs have the potential to markedly change the natural history of premature atherosclerosis that occurs in untreated patients with FH.