ANTIHYPERLIPIDEMIC DRUGS Flashcards
What is ezetimibe, what is the mechanism of action and how well does it work?
Ezetimibe decreases the absorption of cholesterol in the intestine by inhibiting the NPC1L1 protein in the intestines (regulates cholesterol absorption). Lowers LDL levels by ~15-20% and reduces CVD risk when combined with statin therapy. Ezetimibe is able to decrease the levels of serum cholesterol, however its efficacy in decreasing CVD risk alone is marginal and is better when combined with statin therapy.
How are fats classified and what are the merits/disadvantages of different types of fats?
Fats are classified as either saturated, monosaturated, trans fats and polyunsaturated. Saturated and trans fats are associated with an increase in CVD –> small amount of trans fats found in milk (controversy whether this is harmful). Monounsaturated fats such as such as oleic acid (found in olive oil) are associated with a decrease in CVD and is important in the mediterranean diet. Polyunsturated fats are associated with decrease in CVD –> prone to free radical oxidation to produce toxic biproducts.
Most fats found in grass fed animals are rich in omega 6 fatty acids and too much omega 6 is associated with higher TG levels and increased blood pressure. due to increased risk of ASCVD, and a diet rich in omega 3 fatty acids is beneficial to patients with CVD.
what are omega 3 fatty acids and what is the designation for arachidonic acid; for a-linolenic acid?
fatty acids are named for the position of the first double bond in their structure opposite to the position of the carboxylic acid. Omega 3 fatty acids have the first double bond 3 carbon atoms away from the end of the molecule and omega 6 fatty acids have the first double bond 6 carbon atoms away from the end of the molecule.
MOA of statins, how effective are they, what is optimal dosing of statins in terms of timing, and what interaction occurs with coadministration with vitamins.
statins competitively inhibit HMGCOa reductase enzyme which in important in cholesterol synthesis. This essentially works to increase the levels of LDL receptors on the cell surface and increase the uptake of LDL in the cell to decrease circulating LDL concentration. These statins have an efficacy of 15-50% reduction of cholesterol and are very good at reducing risk of CVD, especially post MI high intensity statin therapy is indicated to reduce risk of recurrent MI. Statins with short half lives are usually given in the night time because the HMGCOa reductase enzyme is most active in the nighttime and administration in the nighttime is associated with increased lipid lowering effects. In contrast, statins with a long half life don’t require dosing at certain times and can be given at any time of the day (such as atorvastatin).
Statins work by decreasing circulating LDL levels and decreasing TG and increasing HDL concentrations.
