11.4: Lipid-Lowering Drugs: Statins and Miscellaneous Agents
Hyperlipidemia, a medical condition often referred to as high cholesterol, is characterized by abnormally elevated levels of lipids in the bloodstream. When present in excess, these lipids, specifically cholesterol and triglycerides, can lead to serious health complications, often involving cardiovascular diseases. Illnesses like atherosclerosis, heart attacks, and pancreatitis have all been linked to untreated hyperlipidemia. This means controlling and regulating cholesterol and triglyceride levels is critical to maintaining good health.
Statins are among the most commonly prescribed classes of drugs for treating hyperlipidemia. These include drugs like atorvastatin, simvastatin, and rosuvastatin. Statins function by inhibiting the HMG-CoA reductase, a key enzyme involved in synthesizing cholesterol within the body. This inhibition effectively reduces the levels of intracellular cholesterol. Furthermore, statins enhance the LDL receptor-mediated cholesterol uptake by liver cells. As a result, it further decreases the overall cholesterol levels in the bloodstream.
Oral administration is the preferred method for statin intake due to its high absorption rate in this form. After consumption, the statins are extensively metabolized in the liver, the organ responsible for cholesterol regulation. Despite their efficacy, statins are known to have common side effects. These may include muscle pain, elevated liver enzymes, and, in rare cases, muscle damage.
Apart from statins, other types of lipid-lowering drugs are also available. Bile acid-binding resins, for instance, can reduce LDL reabsorption in the intestines. They promote increased excretion of bile, which in turn encourages the conversion of cholesterol to bile in hepatocytes, effectively reducing cholesterol levels.
Fibrates and niacin are also prescribed to lower serum triglycerides and elevate high-density lipoprotein (HDL) levels. HDLs are often called 'good cholesterol,' as they can carry cholesterol from other body parts back to the liver, which is removed from the body. As a result, higher levels of HDLs are beneficial and can help reduce the risk of heart disease.
