Pharm Section 4 Flashcards
(115 cards)
functions of cholesterol
responsible for proper cell membrane synthesis and the formation of bile acids and steroid hormones
rate limiting step in cholesterol formation
mevalonate
formed by acetyl CoA and catalyzed to HMG-CoA reductase
cholesterol synthesis pathway
acetyl Coa > HMG CoA reductase > mevalonate > farnesyl pyrophosphate > squalene > cholesterol
cholesterol and transportation
hydrophobic, must be transported in blood by hydrophilic lipoproteins
most cholesterol in plasma normally carried in what form?
LDL; low density lipoproteins; “bad cholesterol” associated with increased risk of CAD
apoB
apolipoprotein B; apoB binds lipids to LDLs and acts as ligand to “unlock” cell membranes to allow LCL inside; it is responsible for carrying cholesterol to tissues
the more apoB, the more atherogenic
test for apoB amounts
“Berkeley” cholesterol test
HDL cholesterol
high density lipoprotein; “good cholesterol” because low HDL traditionally seen as strong risk factor for CAD. Recent data is challenging this.
triglycerides
carried in chylomicrons, VLDL (very low), and IDL (intermediate)
ATP IV guidelines (new 2013)
do away with specific goals (numbers) for LDL and instead categorize patients into four groups of primary and secondary prevention patients. Recommend “intensity” of tx for each prevention group in order to achieve desired LDL cholesterol reduction. No evidence to support specific target. May increase people on statins by 70 million in US (1/2 US pop 40-75).
ATP four new guideline documents include…
- tx of blood cholesterol in adults
- assessment of CV risk
- lifestyle management to reduce CV risk
- management of overweight and obesity in adults
ATP IV new risk categories for hyperlipidemia patients
- with CV disease; 40-75 years old; >=7.5% calculated risk for MI or stroke within 10 years
- with hx MI, stroke, angina, PAD, TIA, or revascularization
- 21 and older with LDL level of 190mg/dL or higher
- 40-75 years old with type 1 or 2 diabetes
ATP IV new guidelines for assessment of CV risk
focus on atherosclerosis as chronic disease that extends beyond the heart
ATP IV new guidelines for lightly management to reduce CV risk
recommendations cover evidence related to dietary patterns, nutrient intake, and levels/types of physical activity
ATP IV new guidelines for management of overweight/obese adults
BMI as quick, first screening step for wright loss counseling; waist circumference as indicator for T2 diabetes, CVD, all-cause mortality; new recommendations for BMI cutoff for treatment recommendations (was BMI30 or [25 +2comorbidities], now BMI25 and 1 comorbidity)
AACE response to ATP IV guidelines?
they reject the new guidelines and question their scientific basis. say certain at-risk populations will be underserved by new guidelines
Metabolic syndrome
–formerly syndrome X
–describes patients with three or more of: …obesity (waist circ >40in M/ >35in F)
…dyslipidemia (triglyceride >150; HDL <40 M/ <50 F)
…HTN (>135/85 mmHg)
…diabetes (FBG >110mg/dL)
HMG-CoA reductase inhibitors are also called…?
statins
most widely used drugs for dyslipidemia
first statin drug
lovastatin (Mevacor); 1987
how do statins work?
inhibit cholesterol synthesis
inhibit HMG-CoA reductase (rate-limiting step in cholesterol synthesis), which aids in removal of cholesterol from blood
how is ubiquinonse/coenzyme Q10 related to cholesterol? what might it be related to?
other side of the pathway for cholesterol production
deals with muscle properties, so may be related to myopathy side effects of statins
may be helpful to give statins with CoQ10 supplement
statin impact on LDL, HDL, total cholesterol and triglyceride concentrations
lower plasma concentration of LDL
lower total cholesterol
reduce levels of triglycerides
increase levels of HDL
statins must be taken for how long?
indefinitely. if stopped, cholesterol will return to baseline within a few weeks
statins may be beneficial for what non-CV conditions?
improved endothelial function
decreased platelet aggregation
reduced inflammation