11.14 Lipid-Lowering Agents Flashcards Preview

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Flashcards in 11.14 Lipid-Lowering Agents Deck (41)
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1
Q

VLDL

A

-basically triglycerides (very low density lipoprotein)

2
Q

LDL

A

low density lipoprotein

  • bad cholesterol
  • VERY high correlation with Atherosclerosis, the higher levels of LDL=higher risk of atherosclerosis
3
Q

HDL

A

high density lipoprotein

-the higher the level of HDL the less correlation with atherosclerosis

4
Q

LPL

A

lipoprotein (TG) Lipase

-takes triglycerides and cleaves into free fatty acids

5
Q

Rate limiting step Cholesterol synthesis (in the liver)

A

HMG-CoA Reductase

6
Q

cholesterol containing lipoproteins

A

IDL, LDL, HDL

7
Q

Resins (bile acid sequestrants) MOA

A

ex: cholestyramine
1. Bind bile salts and block enterohepatic cycle of bile acids.
2. Lower cellular cholesterol content by ↑bile acid synthesis.
3. Increase LDL receptors in liver.
4. Rise in receptor-mediated endocytosis of LDL lowers plasma LDL levels.
5. Increase in cholesterol biosynthesis (bad).
6. Increase in plasma VLDL levels (bad) [do not use in patients with elevated VLDL ie. TGs]

8
Q

Beneficial Effects of Resins

A

Lower LDL levels about 15 to 25%
Increase HDL levels about 10%
Relatively safe drugs (no systemic absorption) Good combo agents with statins or niacin Safest to use in pregnancy and children Decrease morbidity and mortality of CAD

9
Q

Adverse Effects of Resins

A

Gritty bad taste, patients don’t like Increase cellular cholesterol biosynthesis
Increase plasma VLDL levels (do not use in patients with ↑VLDL, TGs).
GI: nausea, constipation, heartburn, bloating (less with Colesevelam [Welchol])
Decreases absorption of other agents
- fat soluble vitamins A, D, E & K
- aspirin, warfarin, thiazide, digoxin, phenobarbital

10
Q

Statins, examples

A

Atorvastatin (lipitor?) and simvastatin (prodrug) and lovastatin

11
Q

Statin MOA

A
  1. Competitive inhibitors of HMG-CoA reductase (rate-limiting step) which regulates cholesterol formation.
  2. Decreased cellular cholesterol level increases LDL receptors.
  3. Rise in receptor-mediated endocytosis of LDL lower plasma LDL levels. [15-50%] Best class.
  4. Modest increase in HDL levels (10%)
  5. Statins + Resins are good combination for lowering elevated LDL levels.
  6. Atorvastatin and simvastatin also lower VLDL.
12
Q

Beneficial Effects of Statins

A

Lower plasma LDL levels, best agents (15 to 50%) Increase plasma HDL levels (10%)
Atorvasatin & Simvastatin also lower plasma VLDL Combo Rx with Resins to lower plasma LDL Reduce morbidity and mortality of CAD
Best if taken evenings with food

13
Q

Adverse Effects of Statins

and what other drug should be avoided when taking statins (CIs)?

A

May produce headaches, rashes and myopathy (muscle disease, weakness)
May cause rhabdomyolysis (muscle wasting) and liver injury (higher doses). Monitor liver function
- alanine aminotransferase (ALT)
- aspartate aminotransferase (AST)
Rhabdomyolysis potentiated with Gemfibrozil (avoid).
Caution: elderly, women (CI: pregnancy), children (<12), hypothyroidism, renal and liver dysfunction and drug interactions (cytochrome P450, reduced metabolism).

14
Q

Fibrates -examples

A

Gemfibrozil, Fenofibrate, Clofibrate

best agent for lowering triglycerides and second best for…

15
Q

Fibrates - MOA

A

Gemfibrozil, Fenofibrate,

  1. Increase VLDL (TG’s) clearance by increasing LPL activity (best agent). Via activation of peroxisome proliferator activated receptor α (PPARα).
  2. Decrease VLDL production by inhibiting adipose tissue lipolysis (decrease TGs 20-50%)
  3. Lowers IDL and LDL production and content.
  4. Increase HDL levels (20-30%).
  5. Lipoproteins: Lowers VLDL (TG’s), IDL and LDL.

Dosage: oral dose 1 to 2 times per day gemfibrozil (600 mg) fenofibrate (67 mg), fenofibrate > potency than gemfibrozil.

16
Q

Beneficial Effects of Gemfibrozil, Clofibrate & Fenofibrate (Fibrates)

A

Lower plasma VLDL (primary), IDL and LDL.
Greatest decrease in plasma TG’s (VLDL, 20-50%)
Increase plasma HDL (20 to 30%) Reduces morbidity and mortality of CAD Fenofibrate is more potent than Gemfibrozil

17
Q

Adverse Effects of Fibrates

A

GI distress (discomfort), rashes and headaches
May produce liver injury
Gemfibrozil potentiates myopathy with statins, combination should be avoided
Fenofibrate is safer to use with statins
May increase risk of gallstones (esp. Clofibrate)

18
Q

Omega 3 Fatty Acids

A

work by decreasing the synthesis and release of VLDL, thus lowering TG levels
• Salmon, flaxseed, canola oil, soybean oil and nuts
• Diets rich in omega 3 fatty acids from oily fish decrease TC, TG, LDL, increase HDL & decrease CV events
• Reduces TG by inhibition of VLDL-TG synthesis and apoprotein B (assoc. with LDL receptor binding)
• Rx fish oil: Lovaza®: ↓TG 14-30%, ↑HDL ~10%
• FDA approved as adjunct for high TG levels (> 500 mg/dL)
• Thrombocytopenia, bleeding disorders (high doses)
• < 3 g/day generally recognized as safe

19
Q

adverse effects of Omega 3 fatty acids

A

-thrombocytopenia (destruction of platelets) bleeding disorders (high doses)
- GI disturbance
- fishy aftertaste
- increased bleeding risk
- worsening glycemic control (↑CHO)
44

20
Q

statins are the most powerful agent for what?

A

lowering “bad cholesterol” (LDL)

21
Q

SE: liver toxicity

A

statins

22
Q

SE: myopathy

A

statins

23
Q

CI: pregnancy

A

Statins

24
Q

CI: liver Disease, peptic ulcer

A

Niacin

25
Q

SE: flushed face

A

nicacin

26
Q

what is the best class for lowering TGs?

A

Fibrates

27
Q

increased risk for gall stones with what class of drugs?

A

fibrates

28
Q

SE: thrombocytopenia

A

Omega-3 fatty acids

thus bleeding is a concern with these

29
Q

Factors Increasing HDL Levels

A

Increased HDL levels are antiatherogenic
HDL enhances the clearance of LPs and Cholesterol Exercise
Moderate Alcohol Intake
Weight Reduction (overweight)
Stop Smoking
Lipid-lowering drugs (Pharmacotherapy)
(Resins, Statins, Fibrates, Ezitimibe & Niacin)

30
Q

what are the undesirable effects of resins? and when are they contra-indicated?

A
  • Increase in cholesterol biosynthesis (bad).

- Increase in plasma VLDL levels (bad) [do not use in patients with elevated VLDL ie. TGs]

31
Q

what group of drugs is the best agent for lowering the level of LDL in plasma?

A

Statins (Atorvastatin, Simvastatin, Lovastatin)

32
Q

Ezetimibe - MOA

A
  1. Inhibits cholesterol absorption in intestinal cells.
  2. Reduce cholesterol transport system in intestinal cell wall. 3. Reduces cholesterol absorption by more than 50%.
  3. Reduces LDL by 18%.
  4. Reduces VLDL by about 5%.
  5. Increases HDL by about 3%.
  6. Ezetimibe enhances the lipid-lowering effects of statins.
    7**. In combination with statins enhances the reductions in LDL and VLDL. Less statin required to significantly lower LDL and VLDL (clinical value now in question?).
  7. Dosage: 10 mg oral dose alone or combo with statins (?).
33
Q

Rationale for Co-administration of Ezetimibe with Statins

A

One-step co-administration of ezetimibe similar to three-step statin titration

34
Q

Beneficial Effects of Ezetimibe

A

Reduces Plasma LDL (18%)
Reduces Plasma VLDL (5%)
Increases Plasma HDL (3%)
**Enhance the lipid-lowering effects of statins.

35
Q

adverse effects of Ezetimibe

A

No adverse effects identified (safe drug??) Minor: headache, diarrhea
Increase cancer risk (?)

36
Q

Niacin (Nicotinic Acid or Vitamin B3 )

A
  1. Decrease VLDL production by inhibiting adipose tissue lipolysis (main action,
37
Q

what is the best agent for increasing HDL levels (20-50%)?

A

Niacin (nicotinic acid or vitamin B3)

38
Q

Beneficial Effects of Niacin

A
  • Lower plasma VLDL (primary), IDL and LDL.
  • Increases plasma HDL (20 to 50%) [best HDL stimulator]
  • Reduce morbidity and mortality of CAD
39
Q

Adverse Effects of Niacin

A

GI discomfort, facial and chest flushing (involves PG’s, reduced if aspirin taken just prior, now available as combo Rx), rashes and itching
Potentiates gout (decrease uric acid secretion), diabetes (glucose intolerance) and peptic ulcers
May produce liver injury
CI: active liver disease, peptic ulcer

40
Q

when is Niacin CI?

A

active liver disease, peptic ulcer

41
Q

what drug/class of drugs produce the greatest decrease in plasma TG’s (VLDL, 20-50%)?

A

the Fibrates (Gemfibrozil, Clofibrate & Fenofibrate)