Drugs for atherosclerosis reduce cardiovascular risk by lowering atherogenic lipoproteins, stabilizing existing plaques, and mitigating inflammation within the arterial wall. Atherosclerosis is a chronic inflammatory disease characterized by lipid accumulation, endothelial dysfunction, and plaque formation in medium and large arteries. Pharmacological intervention targets multiple steps in this process, with LDL cholesterol reduction serving as the primary therapeutic goal.
What Is Atherosclerosis Pharmacotherapy?
Pharmacotherapy for atherosclerosis aims to prevent initial cardiovascular events (primary prevention) or reduce the risk of recurrence in patients with established disease (secondary prevention). The relationship between LDL cholesterol and cardiovascular risk is log-linear, and contemporary guidelines emphasize intensive LDL lowering for high-risk patients. Beyond lipid modification, some agents exert pleiotropic effects on endothelial function and plaque stability.
Drug Classes and Mechanisms
Statins (atorvastatin, rosuvastatin, simvastatin) competitively inhibit HMG-CoA reductase, the rate-limiting enzyme in hepatic cholesterol synthesis, leading to upregulated LDL receptor expression and increased clearance of circulating LDL. They also reduce triglycerides and modestly increase HDL cholesterol. Ezetimibe inhibits the NPC1L1 transporter at the intestinal brush border, reducing dietary and biliary cholesterol absorption. PCSK9 inhibitors (evolocumab, alirocumab) are monoclonal antibodies that block proprotein convertase subtilisin/kexin type 9, preventing LDL receptor degradation and markedly increasing LDL clearance. Fibrates (fenofibrate, gemfibrozil) activate PPAR-alpha, reducing triglycerides and raising HDL through increased lipoprotein lipase activity. Bile acid sequestrants (cholestyramine, colesevelam) bind bile acids in the intestine, interrupting enterohepatic circulation and depleting the hepatic cholesterol pool. Omega-3 fatty acids (icosapent ethyl) reduce triglycerides through multiple mechanisms including decreased hepatic VLDL production.
Therapeutic Uses
Statins are first-line therapy for both primary and secondary prevention, with high-intensity statins (atorvastatin 40 to 80 mg, rosuvastatin 20 to 40 mg) recommended for patients with established atherosclerotic cardiovascular disease. Ezetimibe is added when statin monotherapy does not achieve LDL targets or as alternative therapy in statin-intolerant patients. PCSK9 inhibitors are reserved for patients with familial hypercholesterolemia or those requiring additional LDL reduction despite maximal statin and ezetimibe therapy. Fibrates and omega-3 fatty acids are used primarily for hypertriglyceridemia.
Adverse Effects
Statins may cause myalgia, elevated transaminases, and rarely rhabdomyolysis. Ezetimibe is well tolerated with occasional gastrointestinal symptoms. PCSK9 inhibitors cause injection site reactions and rarely hypersensitivity. Fibrates increase the risk of gallstones and myopathy, particularly when combined with statins. Bile acid sequestrants cause gastrointestinal distress and may impair absorption of fat-soluble vitamins and other medications.
Key Clinical Considerations
LDL reduction targets are stratified by cardiovascular risk, with a target of less than 55 mg/dL for very high-risk secondary prevention patients. Statin therapy should not be discontinued for mild transaminase elevations in the absence of clinical evidence of liver injury. Drug interactions are important for statins metabolized by CYP3A4 (atorvastatin, simvastatin) versus those that are not (rosuvastatin, pravastatin). Patient adherence to lifelong therapy remains a significant challenge.
Conclusion
Lipid-lowering therapy is a cornerstone of atherosclerotic cardiovascular disease prevention. Statins remain the foundational agents, with ezetimibe and PCSK9 inhibitors providing additional benefit for patients requiring intensive LDL reduction. A risk-stratified approach to treatment intensity, combined with attention to tolerability and adherence, optimizes long-term cardiovascular outcomes.
