Lipid-Lowering Agents

Frequently asked questions

Which drugs belong to the group of HMG-CoA reductase inhibitors (statins)?

The group of HMG-CoA reductase inhibitors (statins) includes the following medications:

• Simvastatin — blocks the key enzyme of cholesterol synthesis in the liver;
• Atorvastatin — an inhibitor of cholesterol synthesis;
• Rosuvastatin — an inhibitor of cholesterol synthesis;
• Lovastatin — inhibits cholesterol synthesis within hepatocytes;
• Pravastatin — inhibits cholesterol synthesis within hepatocytes.

What is the molecular mechanism of action of fibrates?

At the molecular level, the mechanism of action of fibrates involves the activation of PPAR$\alpha$ nuclear receptors (peroxisome proliferator-activated receptors). This leads to the following effects:

• expression of endothelial lipoprotein lipase and stimulation of its activity;
• increased synthesis of apoproteins Apo A (apoA-I and apoA-II);
• inhibition of hepatic cholesterol synthesis;
• increased density of lipoprotein receptors on hepatocytes.

As a result, the catabolism of triglyceride-rich particles is accelerated.

What side effects are most characteristic of statins?

Statins are characterized by adverse effects affecting various body systems.

• General reactions — dyspeptic disorders, central nervous system disturbances (insomnia, headache), and cutaneous manifestations (erythema, rash).
• Hepatotoxicity — a dose-dependent effect that may manifest as elevated liver transaminases.
• Muscle tissue injury — occurs infrequently but represents the greatest danger, manifesting as myopathy and rhabdomyolysis (destruction of muscle tissue).

Which drugs are classified as bile acid sequestrants?

The group of bile acid sequestrants includes the following anion-exchange resins:

• Cholestyramine — forms non-absorbable complexes with bile acids in the intestinal lumen;
• Colestipol — possesses approximately equal therapeutic efficacy to cholestyramine.

Both drugs disrupt enterohepatic circulation and enhance the excretion of bile acids from the body in feces.

Which specific enzyme is inhibited by nicotinic acid preparations in adipose tissue?

In adipose tissue (adipocytes), nicotinic acid preparations inhibit the enzyme triglyceride lipase (also designated as TAG lipase or triacylglycerol lipase). Suppression of this enzyme's activity leads to the following effects:

• decrease in intracellular lipolysis in adipocytes;
• reduction in the formation of free fatty acids;
• decrease in the transport of free fatty acids from adipocytes to the liver.

What is the main ultimate goal of prescribing lipid-lowering agents?

To reduce the content of atherogenic lipoproteins in blood plasma, which is achieved by suppressing the synthesis of cholesterol and VLDL.

How do intestinal cholesterol absorption inhibitors work?

They inhibit a specific sterol transporter in the intestine, which decreases the incorporation of cholesterol into chylomicrons. The drug can be used as monotherapy or combined with statins.

What happens to HDL levels during therapy?

As a concurrent effect, a compensatory increase in the level of high-density lipoproteins, which possess protective antiatherogenic properties, is frequently observed.