Block 4 Pharmacology Final Exam

How venodilator treatment reduces preload/end-diastolic volume - by decreasing venous return How arterial dilator treatment reduces afterload/end-systolic volume - by decreasing arterial/aortic pressure Description of O2 supply of heart - ATP synth by aerobic metab w/ interm O2 supply (not continuous bl supp b/c BVs supp myocard constr during systole) - extr up to 70% O2 from blood Pathophysiology of IHD - 1). Stable angina = chron disr bl supp to myocard tiss by asymp athero plaque 2). Stable ischemia/angina = stab fixed athero plaque 3). Unstable ischemia/angina = plaque disr+plt aggreg but not yet thrombus formation 4). NSTEMI = thrombus form but not compl occlusive 5). STEMI = compl occl thromb Angina Pectoris Description & Types - press-like discomf/pain from myocard isch/underl athero -- O2 demO2 supp - IHD = angina+MI - Typ ang = O2 dem incr (ie. exerc/stress) but cor bl fl+O2 supp lim by athero - Stab ang = sim angina attacks each time - Unstab ang = ang attacks worse each time by rup plaque; MI forerunner - Variant/Prinzmetal's ang = ac cor vasosp w/ pain @ rest -- TREAT w/ CCBs/BBs Drug Classes used for Stable Angina Treatment - - Nitrites & Nitrates - CCBs - BBs - Drugs modifying myocard metab General Pharmacology of Drugs for Stable Angina Treatment - - Incr O2 supp by: incr reg fl distrib by nitrates, CCBs, BBs & incr cor bl fl by nitrates, CCBs - Decr O2 dem by: decr HR+contractility by BBs, CCBs & decr wall tens (pre+afterload) by nitrates, CCBs Examples & Use of Nitrites in Stable Angina Treatment - Amyl nitrite for ac ang by inhal Examples & Use of Nitrates in Stable Angina Treatment - incl nitroglycerin, isosorbide dinitrate, isosorbide mononitrate - Use = prev+treat ang attacks by pref relax ven sm musc (venodil) - IV nitro also for MI-assoc ac HF MOA & Effects of Nitrites & Nitrates in Stable Angina Treatment - - MOA = biotransf prod NO activ guanylyl cyl -- cGMP --sm musc relax -- vasodil (pref in veins) - Effects = pref dil ven sm musc to red preload -- decr vent wall tens -- decr O2 dem; cor art dil -- incr cor bl fl+distrib to subendoc -- incr O2 supp Block 4 Pharmacology Final Exam Onset & Duration of Action of Nitroglycerin, Isosorbide dinitrate, Isosorbide mononitrate - - SL Nitro = onset 2 mins, dur 25 mins - PO sust-rel Nitro = onset 35 mins, dur 4-8 hrs - TD Nitro = onset 30 mins, dur 8-14 hrs **useful for prev nocturnal angina** - SL IsoD = onset 5 mins, dur 1 hr - PO slow-rel IsoD = onset 30 mins, dur 8 hrs - PO ext-rel IsoM = onset 30 mins, dur 12 hrs Therapeutic Uses & AEs of Nitrates - - Uses = prev+treat ang attacks - AEs = excess vasodil -- HA, hypoTN, dizz; refl tachy by sympa stim -- incr O2 dem so BB w/ nitrate to prev tachy; Tolerance by mitoch aldehyde dehydrog inactiv biotransf nitro -- interrupt ther for 8-10hr/day to restore resp DIs for Nitrates - w/ Sildenafil (Viagra) for ED -- serious hypoTN Types of Ca Channels in Smooth Muscle Cells & Cardiomyocytes - - Sm musc cells = L+T-type -- vasocon - Cardiomyocytes = L-type only -- card contractility, SA automaticity, AV cond vel Examples & Potency of Dihydropyridine CCBs - - Amlodipine - Felodipine - Isradipine - Nicardipine - Nifedipine - Nimodipine - Nisoldipine potent vasodils w/ min/no effect on heart, MOSTLY @ BVs for stab/var angina treatment **incr O2 supp** Examples & Potency of Phenylalkylamine & Benzothiazepine CCBs - - Verapamil (phenylalkylamine) & Diltiazem (benzothiazepine) act @ both heart & BVs -- decr SA node autom, decr AV node cond vel, decr card contractility for stab/var angina treatment **incr O2 supp+decr O2 dem** **SUPERIOR for IHD treatment**