Describe the four pro-atherogenic effects of oxidised LDL
- Inhibits macrophage motility
- Induces T-cell activation and VSMC division / differentiation
- Toxic to endothelial cells
- Enhances platelet aggregation
What are the indications for statins?
- CV risk prevention (CVD + DM)
- Familial Hypercholesterolaemia
Describe the three ways in which statins act as a lipid-lowering drug
- Inhibit cholesterol synthesis in hepatocytes
- Increase clearance of IDL and LDL
- Decrease production of VLDL and LDL
What are the possible adverse reactions of statin drug treatment?
- Increased transaminase levels – rapidly reversible, no evidence of chronic liver disease
- Myopathy – seen when higher doses of statins are used in combination with other drugs
- Miscellaneous – GI complaints, arthralgias, and headaches
Identify four secondary benefits of statin treatment
- Anti-inflammatory
- Plaque reduction
- Improved endothelial cell function
- Reduced thrombotic risk
Describe the structure and function of fibric acid derivatives
- Structure: ampipathic carboxylic acids
- Function:
I. PPARα agonist – increases production of lipoprotein lipase
II. Reduces triglyceride production
What are the indications for fibric acid derivatives?
- Adjunctive therapy to diet
- Hypertriglyceridemia
- Combined hyperlipidemia with low HDL (do not respond to NA)
What are the contraindications for fibric acid derivatives?
- Hepatic or renal dysfunction
- Pre-existing gallbladder disease
What are the possible adverse effects of fibric acid derivatives?
- GI upset
- Cholelithiasis
- Myositis
- Abnormal LFTs
Describe the three ways in which nicotinic acid acts as a lipid-lowering drug
- Reduces VLDL and increases HDL at high doses
- Lipid lowering effect by inhibition of lipoprotein synthesis
- Reduces coronary events
What are the possible adverse effects of nicotinic acid?
- Flushing, itching, headache
- Hepatotoxicity
- Activation of peptic ulcer
- Hyperglycemia and reduced insulin sensitivity
What are the contraindications of nicotinic acid?
- Active liver disease
- Unexplained LFT elevations
- Peptic ulcer disease
Describe the three ways in which ezetimibe acts as a lipid-lowering drug
Ezetimibe selectively inhibits intestinal cholesterol absorption:
- ↓ intestinal delivery of cholesterol to the liver
- ↑ expression of hepatic LDL receptors
- ↓ cholesterol content of atherogenic particles
What are the possible adverse effects of ezetimibe
- Headache
- Abdominal pain
- Diarrhoea
Describe how lipid lowering drugs can be used in combination therapy
Statin plus:
- Fibrate (not gemfibrozil)
- Nicotinic acid
- Ezetimibe
- Omega-3 fatty acids
- Resins
What should one consider when assessing the use combination therapy of lipid lowering drugs
- Benefit (CV risk reduction)
- Cost
- ADRs
In three steps, explain why gemfibrozil is not the fibrate of choice in combination fibrate + statin therapy
⇒ Fibrate + statin therapy may significantly improve triglyceride, LDL-C, and HDL-C levels
⇒ However, fibrates + statins are associated with increased risk for myopathy and rhabdomyolysis
⇒ Gemfibrozil may impair glucuronidation of statins
Complete the table by indicating whether the drug increases/decreases or does not affect the listed lipid parameter
Drug - LDLChol - HDLChol-TGs
Statin
Ezetimibe
Nicotinic acid
Cholestyramine
Omega 3 FA
Fibrate
Reduce-Reduce-Raise
Raise-Reduce-Reduce
Raise-Raise-None
Reduce-Reduce-Raise
Reduce-Reduce-Reduce
None/Increase-Reduce-Reduce
Provide two examples of a lipid-lowering drug
- Simvastatin
- Atorvastatin
