Drug Therapy of Angina Pectoris Lecture PDF Flashcards
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Most common source of angina is due to what underlying physiologic mechanism?
Atherosclerosis
3 types of angina
- chronic stable (exertional)
- variant (vasospastic)
- unstable (part of acute coronary syndrome)
Nitroglycerin DOC and mech of action
- Drug of choice for acute anginal attacks
- Acts directly on vascular smooth muscle to promote vasodilation, acts mostly on veins in peripheral vasculature than arteries (reduces O2 need for heart muscle)
Nitroglycerin therapeutic uses (3)
- treat acute angina to abort ongoing attack
- treat chronic stable angina by decreasing cardiac oxygen demand
- variant angina treatment relaxing vasospasm of coronary arteries increasing oxygen supply
Nitroglycerin ADR’s (3)
- headache (can be diminished over time)
- orthostatic hypotension
- reflex tachycardia (can be prevented by coadministration with B1 receptor or Ca2+ channel blocker)
Nitroglycerin drug interactions (2)
- intensifies other hypotensive drugs
- phosphodiesterase type 5 inhibitors for ED (sildenafil and such) causes drop in blood pressure
Nitroglycerin drug tolerance
-occurs with depletion of sulfhydryl groups in VSM and can develop rapidly over the course of a day, preventing from nitroglycerin from being converted to active form nitric oxide, development is more likely with high dose or uninterrupted therapy, can prevent by witholding for period of time (over night) to replensih sulfhydryl groups
Nitroglycerin for prophylaxis of angina
Preparations used to be taken just prior to anticipated exertion to prevent an attack from occurring
Nitroglycerin administration (4)
- sublingual tablet for direct short term effect (can take up to 2 additional tablets at 5 min intervals, if doesn’t relieve then probably MI)
- oral capsule for long term prophylaxis
- ointment or patch
- IV (often for CHF associated with acute MI)
B adrenergic blocking agents are important for treating ___ angina pectoris but are not effective against _______
stable, vasospastic angina
B blocker sudden abrupt withdrawal
results in excess of sensitive B 1 adrenergic receptors that can increase incidence and intensity of anginal attacks, may precipitate an MI
B blockers should not be used in patients with these 3 conditions
- sick sinus syndrome
- heart failure
- 2nd or 3rd degree heart block
3 most common Ca2+ channel blockers
- verapamil
- dilitiazem
- nifedipine
Ca2+ channel blockers can treat ___ and ___ angina
variant (cardiac spasm)
classic (reduce o2 demand on heart)
Ranolazine (ranexa) function
Approved for treatment of angina in patients that have not adequately responded to nitrates, BB or CCB’s and should be combined with at least one of these drugs, act by unknown mechanism