Term
what is the purpose of hypolipidemics? |
|
Definition
to treat hyperlipoproteinemias that cause atherosclerosis/CAD, increase the risk of mortality to heart disease and stroke, and treat hypertriglyceridemia that can cause acute pancreatitis |
|
|
Term
what is the first step in determining treatment of pts with hypolipidemics? |
|
Definition
assessment of risk status, presence of CAD/family hx, diabetes, HTN, smoker, age, and sex |
|
|
Term
what are the major lipids, how are they transported? what are apoproteins? |
|
Definition
cholesterol and triglycerides - which are transported as lipoproteins. apoproteins are surface proteins on lipoproteins that interact with tissue membrane receptors such as apoB100 for LDLs |
|
|
Term
|
Definition
|
|
Term
which lipoprotein do the bile acid resins bind to? |
|
Definition
|
|
Term
how do VLDLs become LDLs? |
|
Definition
through the action of lipoprotein lipase |
|
|
Term
what is the main function of HDLs? |
|
Definition
to remove cholesterol from the arteries and tissues as well as inhibit oxidation of atherogenic LPs |
|
|
Term
how is risk associated with LP(a) determined? |
|
Definition
genetically, and it is a risk factor for CAD |
|
|
Term
|
Definition
|
|
Term
what is the general metabolism of cholesterol of hepatic origin? |
|
Definition
cholesterol is packed into golgi vesicles either from incoming lipoproteins or from the body's own production (via HMG-CoA reductase, which makes mevalonic acid - a cholesterol precursor). the liver sends out VLDLs which are degraded to LDLs by LPL, which give some of their apoproteins to HDL |
|
|
Term
what is normal in terms of LDL levels? |
|
Definition
<150 mg/dl (<100 if vascular disease) |
|
|
Term
how can LDL levels be calculated? |
|
Definition
LDL = total cholesterol - HDL - TG/5 |
|
|
Term
if the LDL/HDL ratio is above ______ then the pt is considered at risk for CAD |
|
Definition
|
|
Term
what is the method of action for bile acid-binding resins? |
|
Definition
by ion exchange with bile acids, these prevent GI bile acid reabsorption back to the liver - preventing fats and cholesterols from being absorbed by the small intestine in the micelles that bile salts form |
|
|
Term
what is the result of using bile acid-binding resins? |
|
Definition
there is a compensatory increase in liver bile acid synthesis - liver LDL receptors are increased to take up/remove LDL cholesterol from the plasma - this is a beneficial effect |
|
|
Term
are bile acid-binding resins used in combination with any other drugs? |
|
Definition
yes, bile acid-binding resins are considered second line drugs and are often used in combination for synergistic effects w/statins, niacin, and fibrates |
|
|
Term
what are the three bile acid-binding resins that we need to know? |
|
Definition
cholestyramine, colestipol, and colesevelam (which has lower adverse affects - doesn't interact w/other drugs) |
|
|
Term
can bile acid-binding resins increased HDLs? |
|
Definition
|
|
Term
what are ADRs for bile acid-binding resins? |
|
Definition
GI, nausea, bloating, belching, gas, heartburn, constipation, impaired absorption of fat sol. vitamins, impair absorption of drugs (esp acidic compounds, anticoagulants, diuretics, digitalis, and some statins **except colesevelam**), and it **may increase VLDL-triglyceride levels in pts with elevated TGs, due to increased liver TG synthesis |
|
|
Term
what is the M/A for HMG-CoA reductase inhibitors (STATINS)? |
|
Definition
HMG-CoA reductase inhibitors are competitive inihibitors of HMG-CoA reductase (they bear a strong structural similarity to mevalonate) in their rate limiting step - which significantly reduces endogenous liver cholesterol synthesis |
|
|
Term
what is the effect of HMG-CoA reductase inhibitors (STATINS) on LDL and LDL receptors? |
|
Definition
plasma LDL is decreased b/c HMG-CoA reductase inhibitors force an increase in LDL receptors, which then increases the intake of plasma LDL |
|
|
Term
when is the best time for HMG-CoA reductase inhibitor (STATIN) administration? |
|
Definition
in the evening due to the diurnal pattern of cholesterol synthesis *except for pravastatin, whose absorption is increased with food* |
|
|
Term
what is the synergistic effect of combining statins and bile acid binding resins? |
|
Definition
endogenous cholesterol production is blocked and bile acids are not retained, each individually lowering the cholesterol level and both contributing to increased LDL receptors which increase the level of plasma LDL being taken up |
|
|
Term
what are the statins (HMG-CoA reductase inhibitors) we should know? |
|
Definition
rosuvastatin, atorvastatin, simvastatin, lovastatin, and pravastatin |
|
|
Term
do statins decrease TGs? increase HDLs? how do they affect vascular disease? |
|
Definition
statins decrease TGs, increase HDLs, and inhibit platelet aggregation/decrease inflammatory markers/increase fibrinolysis/and **increase endothelial function - eNOS upregulation/activity (increase vasodilation) |
|
|
Term
what are the ADRs associated with statins? |
|
Definition
increased liver *AST, *ALT, CPK (creatine phosphokinase). hepatitis, myopathy, (increased myoglobin can lead to renal failure) myositis w/flu-like symptoms, rhabdomyolysis, rash, pruritus, dryness, carcinogenicity, teratogenicity, interactions with DMMS inhibitors/inducers - and contraindicated w/liver disease, alcoholism, after sx, and severe trauma |
|
|
Term
what is the M/A for ezetimibe? |
|
Definition
ezetimibe inhibits jejunal enterocyte uptake of cholesterol by decreasing incorporation into chyolmicrons |
|
|
Term
how does ezetimibe affect TGs and HDL? |
|
Definition
|
|
Term
can ezetimibe be administered with statins? |
|
Definition
yes, usually simivistatin |
|
|
Term
what is the effect of niacin administration? |
|
Definition
niacin/nicotinic acid/vit B3 inhibits adipose lipolysis (inhibiting intracellular lipase which releases FAs from triacylglycerol in the fat stores), decreases FA and thus supply to the liver - which decreases VLDL/LDL synth and increases HDL. **it also lowers Lp(a) |
|
|
Term
what ADRs are associated with niacin? how is this combated? |
|
Definition
intense cutaneous vasodilation/vasomotor flushing/pruritis - prostaglandin activated, therefore preemptive ASA dose 30 min before can help prevent. AST and ALT hepatic transaminase enzymes can also be elevated, there is some risk of hepatitis/hepatic necrosis, and hyperglycemia/glucose intolerance, and **hyperuricemia/gout |
|
|
Term
can niacin be combined with other hypolipemics? |
|
Definition
yes, niacin is combined with lovastatin, which further decreases LDL and increases HDL |
|
|
Term
what are contraindications/precautions for niacin? |
|
Definition
pts w/diabetes, peptic ulcers, liver disease, pregnancy, and **gout |
|
|
Term
what is the mechanism of action for fibric acid derivatives? |
|
Definition
fibric acid derivatives can activate nuclear receptors in liver/muscle that **increase lipoprotien lipase, increasing FA oxidation, which decreases TG synthesis and VLDL production and increases HDL (due to increase in apoAI/II) |
|
|
Term
what drug is considered first line for hypertriglyceridemia? |
|
Definition
fibric acid derivatives such as gemfibrozil |
|
|
Term
what are ADRs associated with fibric acid derivatives such as gemfibrozil? |
|
Definition
GI disturbances, cholecystitis, **gallstones, increased liver enzymes/hepatitis, myositis/myopathy and caution when used with statins ** except rosuvastatin for hyperlipoproteinemia** also - rash/allergy risk |
|
|
Term
|
Definition
a newer fibric acid derivative also approved for hypertriglyceridemia that decreases TG/VLDL synthesis, but decreases LDL more favorably than gemfibrozil. it increases HDLs 10-20% |
|
|
Term
what are ADRs for fenofibrate? |
|
Definition
same as gemfibrozil, but lower incidence of myopathy and GI effects |
|
|
Term
what is a potential ADR for administration of bile acid binding resins and pts w/hypertriglyceremia? |
|
Definition
bile acid binding resins can raise TG and VLDL cholesterol concentrations |
|
|
Term
what is a specific ADR for the statins? |
|
Definition
|
|
Term
what is the major increased risk of gemfibrozil administration? |
|
Definition
|
|