Lecture 35: Drugs Affecting Lipoprotein Metabolism Flashcards
What is the paradigm for atherosclerosis generation?
Oxidized LDL is taken up by macrophage to form foamy macrophages
Who should be screened for lipids?
Everyone over 20 years old
Screened for triglycerides, total cholesterol, HDL, LDL
What is ATP when it comes to cholesterol treatment?
Adult Treatment Panel
What is the primary target of hypercholesteremia?
Reduction of LDL to appropriate level
What are the secondary goals in treating hypercholesteremia?
- Decreasing triglycerides and non-HDL cholesterol are secondary goals
- Increasing HDL cholesterol is also a secondary goal
What are LDL cholesterol goals?
Less than 100 or less than 70 if they have CHD
<160 if no risk factors
Highest risk below 70
What is a normal fasting normal TG?
<150
Elevated TG are independent risk factor for CHD
Because they are transported by the lipoproteins
What are non-HDL-C?
VLDL + IDL + LDL
Signficance is now we are trying to target other non-HDL
Aside from LDL
Also a risk factor for CHD
What is the non-HDL-C target?
30 mg/dL higher than LDL-C target
What is considered low HDL?
<40
What is the non-pharmacologic therapy for lipid disorders?
- Diet
- exercise and weight loss
- avoidance of alcohol intake
What are the purposes of the drugs for treatment of lipid disorders?
- reduce LDL-C
i. HMG-CoA Reductase Inhibitors
ii. Cholesterol Absorption Inhibitors
iii. Bile Acid Sequestrants - treat TG-HDL axis
i. Fibrates (Fibric Acid Derivatives)
ii. Omega 3 Fish Oil
iii. Niacin (Nicotinic Acid)
What are drugs that reduce LDL-C?
- HMG CoA reductase inhibitors (statins)
- cholesterol absorption inhibitors (CAI; ezetimibe)
- Bile acid sequestrants (BAS)
What are examples of different types of statins?
Always has a “statin” in the generic name
What is the MoA of statins?
Inhibits cholesterol synthesis
Targets rate limiting step of cholesterol synthesis
MoA = HMG-CoA Reductase Inhibitor
Statin mimics HMG-CoA so competitively binds
To HMG-CoA reductase
-reversible but has much greater affinity
Than normal HMG-CoA
How is the LDL receptor regulated?
Regulated by the amount of cholesterol in the liver
So if you have less cholesterol in the liver, you upregulate the production and migration of the LDL receptor to the liver surface
Thus, statins will decrease cholesterol synthesis which then upregulates LDLReceptors
Why are there very few adverse effects of statins?
Because body upregulates HMG-CoA reductase/LDL receptors to compensate for less cholesterol synthesis
Therefore, total cholesterol level remains about the same even though LDL is reduced in blood
What is the first line therapy for LDL reduction?
Statins
What are the adverse effects of statins?
- Elevated hepatic transaminases (not a big deal)
- muscle-related adverse effects
i. myalgia
ii. myopathy
iii. rhabdomyolysis
Dose-dependent