Hypolipidemic Drugs MCQs

Patients with low high-density lipoprotein (HDL) levels (men Nonpharmacologic measures such as exercise, weight loss, and smoking cessation help to raise HDL levels and have significant cardiovascular benefits. In contrast, use of medications to raise HDL levels does not improve cardiovascular outcomes. Pharmacologic treatment of patients with low HDL levels should focus on lowering LDL cholesterol with HMG-CoA reductase inhibitors (statins), as these are the most effective lipid- lowering drugs for preventing cardiovascular events. Statins are indicated for secondary prevention in all patients with known atherosclerotic cardiovascular disease, regardless of baseline lipid levels. Cationic exchange resin = cholestyramine Essential fatty acids = Omega-3-fatty acid Pharmacologic vitamin= niacin Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg. no. 221

Serious side effects of statins include myopathy and hepatitis. Although mild elevations of liver enzymes are common, significant liver injury (aspartate transaminase/alanine transaminase levels more than 3 times the upper limit of normal) is seen in less than 1% of patients and is usually reversible if the medication is discontinued. Liver function tests are recommended before starting statin therapy; otherwise, routine monitoring is not necessary unless symptoms of hepatic injury develop (eg, fatigue, malaise, anorexia). Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg no. 212

In patients with significant hypertriglyceridemia, fibrates are particularly effective due to their ability to upregulate lipoprotein lipase resulting in increased oxidation of fatty acids (liver, muscles). Gemfibrozil and other fibrates inhibit the rate-limiting enzyme in bile acid synthesis, cholesterol 7-alpha-hydroxylase. The reduced bile acid production results in decreased cholesterol solubility and increased microcrystal precipitation, thereby promoting gallstone formation . As a result, fibrates should be used with caution in patients with preexisting gallbladder disease. Patients on fibrate therapy should also be monitored for myopathy, a risk significantly increased when fibrates are used concurrently with statins. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg no. 1098

Explanation: This patient has elevated LDL cholesterol post-MI despite statin therapy. Therefore, Ezetimibe, Bempedoic acid, and Evolocumab can be added for further LDL reduction. Gemfibrozil is not indicated since triglycerides are normal. Ezetimibe (1): Inhibits intestinal cholesterol absorption → ↓ LDL and total cholesterol. Bempedoic acid (2): Inhibits ATP-citrate lyase → ↓ hepatic cholesterol synthesis → ↓ LDL. Evolocumab (3): PCSK9 inhibitor → prevents LDL receptor degradation → ↑ LDL clearance. Explanation of other options: Gemfibrozil (Option D): Incorrect because it is used for severe hypertriglyceridemia and not for LDL lowering. Key Takeaways: Add Ezetimibe , Bempedoic acid , or Evolocumab if LDL remains high despite statins. Gemfibrozil reserved for hypertriglyceridemia. PCSK9 inhibitors are potent LDL reducers post-MI.

Grapefruit juice inhibits CYP3A4 in the liver, particularly at high doses. This can cause decreased drug elimination via hepatic metabolism and can increase potential drug toxicities. Atorvastatin is metabolized via this pathway. Drugs that may enhance atorvastatin toxicity via this mechanism include phenytoin, ritonavir, clarithromycin, and azole antifungals. Reference: Basic & Clinical Pharmacology by Bertram G. Katzung Fourteenth Edition Pg no.60

HMG-CoA reductase inhibitors (statins) inhibit the rate-limiting enzyme in hepatic cholesterol synthesis. In response to these changes, hepatocytes increase their surface expression of the LDL receptor to increase uptake of circulating LDL. Treatment generally produces a 20%-50% reduction in serum cholesterol and LDL concentration. High-intensity statin therapy reduces the risk of acute coronary events. This risk reduction is greater than that seen with other classes of lipid- lowering medications and is likely due to additional properties of statins. Besides effects on lipids, statins have anti-inflammatory properties improve endothelial dysfunction, and appear to stabilize atherosclerotic plaques. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg no. 217

Nicotinic acid, or niacin, has been used in the treatment of hyperlipidemia for almost 4 decades. It is effective in raising HDL cholesterol levels, as well as lowering triglycerides and LDL levels. Niacin's main side effects are cutaneous flushing, warmth, and itching; these are primarily mediated by release of prostaglandins (particularly PGD2 and PGE2). Aspirin, which inhibits prostaglandin synthesis, can significantly reduce these side effects if given 30-60 minutes before niacin administration. The side effects are also reduced with slow-release preparations or if niacin is taken with meals. They are worst when niacin is first initiated and tend to fade over time due to tachyphylaxis. Reference: Basic & Clinical Pharmacology, Fourteenth Edition By Bertram G. Katzung Pg. no. 221