Antihyperlipidemic Drugs Flashcards
What is hyperlipidemia?
Elevation of plasma cholesterol and or triglycerides
Low HDL levels
Increased risk of cardiovascular mortality is most closely linked to elevated levels of LDL cholesterol and?
Decreased levels of HDL cholesterol
–in addition TAGs present an independent risk factor
What are other risk factors for cardiovascular disease?
Cigarette Smoking
Hypertension
Obesity
Diabetes
Primary cause of hyperlipidemia includes what?
Monogenic Disease
Genetic Polymorphism
Gene Environment Interactions
What are the classifications of lipid disorders?
Type I: Familial Hyperchylomicronemia: increased chylomicrons: Deficiency in LPL or apoCII (Rare)
Type IIA: Familial Hypercholesterolemia: Increased LDL: Decreased or non functional LDL receptor expression
Type IIB: Familial Combined Hyperlipidemia: Increased LDL and increased VLDL. Overproduction of VLDL by the liver (common)
Type III: Familial Dysbetalipoproteinemia: Increased IDL: abnormal apoE
Type IV: Familial HyperTAGs: Increased VLDL. Overproduction and/or impaired catabolism of VLDL (common)
Type V: Familial Mixed TAGs: increased chylomicrons and Increased VLDL. Increased production or decreased clearance of VLDL and chylomicrons
Now secondary hyperlipidemia is common in the adult population. What are the secondary causes in developed countries?
Sedentary lifestyle with excessive dietary intake of saturated fat, cholesterol, and trans fatty acids
OTHER FACTORS:
–alcohol (leads to increased VLDL production)
—type 2 DM (increased VLDL synthesis and reduced chylomicron and VLDL catabolism by LPL. ApoCIII levels are increased) – all due to the insulin resistance
–hypothyroidism
What are the signs and symptoms of hyperlipidemia?
No symptoms
–can lead to symptomatic vascular disease (coronary artery disease and peripheral arterial disease)
High TGs
–can lead to acute pancreatitis
Lipoprotein disorders are detected by measuring serum lipids after a 10 hour fast. What are these values?
Total Cholesterol, TGs, and HDL are measured directly
–LDL are calculated: LDL= TC-(HDL + TG/5)
–only works if TGs are less than 400mg/dl
LDL can be measured directly using plasma ultracentrifugation
Moving on to the drugs, what are the first choice in management of hyperlipidemia?
Statins
–decrease the incidence of major coronary events and death in such patients
Addition of a nonstain lipid lowering agent to a stain can reduce what?
LDL levels further than a statin alone
What are the 5 main classes of drugs available for the treatment of hyperlipidemia?
- HMG-CoA reductase inhibitors
- Niacin
- Bile acid binding resins
- Fibric acid derivatives
- Cholesterol absorption inhibitors
HMG-CoA reductase inhibitors (statins) include atorvastatin, fluvastatin, lovastatin, pravastatin, rosuvastatin and simvastatin. What is their MOA?
Competitive Inhibitors of HMG-CoA reductase
- -the enzyme that catalyzes the first committed step of cholesterol biosynthesis
- -blocking this inhibits cholesterol synthesis which causes the cell to up-regulate LDL receptors.
Statins are the most effective drug at lowering LDL. what is the most potent statin?
Rosuvastatin followed by Atorvastatin followed by simvastatin followed by Lovastatin/pravastatin
What are the clinical uses for statins?
Drug class of choice for LDL reduction and are most widely used class of lipid lowering drugs --reduce cardiovascular mortality
Which patients benefit the least from statins?
Homozygous for familial hypercholesterolemia
–lack functional LDL receptors