Lecture 5: Drugs for Lipid Disorders Flashcards
Dietary measures the management of hyperlipoproteinemia are initiated first unless the pt has evidence of what?
Coronary or peripheral vascular disease
The HMG-CoA reductase inhibitors used in management of lipid disorders end in which suffix?
-statin
What are the most effective agents in reducing LDL levels and best tolerated class of lipid lower agents?
HMG-CoA reductase inhibitors (statins)
Which HMG-CoA reductase inhibitor (statin) is almost completely absorbed when taken orally?
Fluvastatin
Statin absorption is enhanced by what?
Food
Which 3 HMG-CoA reductase inhibitors (statins) have the longest plasma half-lives of 19, 14, and 12 hours?
- Rosuvastatin (19 hrs)
- Atorvastatin (14 hrs)
- Pitavastatin (12 hrs)
Which HMG-CoA reductase inhibitor is not metabolized by CYP450’s?
Pravastatin
What is the MOA of HMG-CoA reductase inhibitors (statins)?
Leads to what changes and overall net effect?
- Inhibit HMG-CoA reductase, the rate-limiting enzyme in cholesterol synthesis
- Depletes intracellular supply of cholesterol –> cell then ↑ the # of cell-surface LDL-receptors = ↑ internalization of circulating LDL
List the HMG-CoA reductase inhibitors in descending order of potency starting with the most potent.
i.e., simvastatin, rosuvastatin, atovastatin, pitavastatin, lovastatin, pravastatin and fluvastatin
Atorvastatin = Rosuvasatin > Simvastatin > Pitavastatin = Lovastatin = Pravastatin > Fluvastatin
List the 4 therapeutic benefits of HMG-CoA reductase inhibitors (statins)?
- Plaque stabilization
- Improvement of coronary endothelial function
- Inhibition of platelet thrombus formation
- Anti-inflammatory effects
When does the majority of cholesterol synthesis occur, thus, is when statins are taken for therapeutic effects?
Nightime
Statins are effective at lowering plasma cholesterol levels in all types of hyperlipidemia and can be used alone, or in combo with what 3 other agents?
- Resins
- Niacin
- Ezetimibe
What may be seen in pt’s with liver disease or a hx of alcohol abuse if they taken a statin?
Elevations of serum aminotransferase activity (up to 3x normal)
*Levels decrease upon suspension of drug therapy
What may be seen in the muscle of patients who take a statin, especially in those with high level of physical activity?
Creatine kinase activity levels may increase
Which AE associated with the muscle can occur rarely and lead to renal injury in those on statins?
Rhabdomyolysis (leading to myoglobinuria)
There is an increased incidence of what AE in pt’s concomitantly taking statins and fibrates?
Myopathy
*Can also occur with monotherapy
Statins increase the levels of which anti-coagulant?
Warfarin
Statins are contraindicated in which subset of patients?
Women who are pregnant, lactating, or likely to become pregnant
Use of statins is not recommended in pt’s with what 2 underlying diseases?
- Liver disease
- Skeletal muscle myopathy
Use of statins in children is restricted to those with what?
Homozygous familial hypercholesterolemia and some pt’s w/ heterzygous disease
Niacin (nicotinic acid, Vit B3) decreases levels of which 3 lipids and increases what?
- Decreases = TG’s, LDL, and Lp(a)
- Increases = HDL
Niacin is converted to nicotinamide and incorporated into NAD, which is well absorbed, and is mainly distributed to which 3 tissues?
- Hepatic
- Renal
- Adipose tissue
What is the MOA of niacin in reducing levels of lipids?
Net effect on FFA’s, LDL, VLDL, and HDL?
- Inhibits lipolysis of TG’s in adipose tissue = ↓ circulating FFA’s
- Reduced hepatic synthesis of VLDL and LDL
- Catabolic rate for HDL is ↓
What is the effect of niacin on levels of tPA and fibrinogen?
- Fibrinogen levels are decreased
- tPA levels are increased
What can be taken before the administration of niacin to reduce the AE of nicain cutaneous flushing?
Aspirin or 1x daily ibuprogen
Niacin may cause toxicity of which organ as an AE?
Levels of what should be monitored at baseline?
- Hepatotoxicity
- Monitor liver function (aminotransferases)
Niacin should be avoided in pt’s with what 2 underlying diseases?
- Hepatic disease
- Active peptic ulcer
Why should niacin be used with caution in pt’s with diabetes mellitus?
Due to niacin-induced insulin resistance –> hyperglycemia
Which cutaneous AE’s may be associated with the use of niacin?
- Pruritus
- Acanthosis nigricans
- Rashes
- Dry skin or mucous membranes
How many times is niacin doses per day?
2-3x daily (half-life is ~60 mins)