Flashcards in Vasodilators Deck (46)
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1
Primary Mechanisms of Action of Vasodilators
Increasing intracellular cGMP
Preventing the depolarization
Decreasing intracellular Ca2+
Increasing intracellular cAMP
2
Nitric Oxide Donors: Mechanisms of Action and Pharmacology
Release NO when metabolized
Relax smooth muscle
Vascular
Corpora cavernosa
Short-lived in others (e.g. bronchial, GI)
Inhibit platelet aggregation
3
NO mech of action
increases cGMP, which causes the breakdown of myosin and actin, causing relaxation in vascular smooth muscle
4
Organic Nitrites and Nitrates
Isosorbide dinitrate
Nitroglycerin
5
Inorganic NO Donors
Nitroprusside
6
Organic NO Donors: Pharmacodynamics (site of action)
NO broken down in veins (relax coronary arteries)
-effect on preload (decreases O2 demand in heart)
7
Inorganic NO Donors: Pharmacodynamics (site of action)
dialate veins and arteries (good antihypertensive)
8
adverse effect of inorganic NO donors
cyanide toxicity
9
Isosorbide
Angina
Heart failure
10
Nitroglycerin clinical use
Acute myocardial infarction†
Anal fissure
Angina (stable and unstable)
Hypertensive emergency* (*=IV)
Hypotension induction*
Perioperative hypertension*
Pulmonary edema†
11
Nitroprusside
Hypertensive emergency (only IV)
12
angina
short-lived ischemia
13
short acting
nitroglycerin, nitroprusside (good for acute events)
14
long acting
isosorbide dinitrate, nitroglycerin (long term use)
15
NO donor tolerance
nitrate-free period of greater than 10 hours are necessary to prevent or attenuate tolerance
-want coverage during the day only (during activity that will lead to angina)
16
nitric oxide donor side effects
Hypotension
Dizziness
Headache
Flushing
Syncope
17
Nitroglycerin and nitroprusside are both pregnancy category
C
18
Isosorbide dinitrate and Nitroglycerin interaction
Sildenafil
19
PDE V
breaks down cGMP
20
Sildenafil mech of action
blocks action of PDE V (build up of cGMP--> relaxation)
21
Sildenafil clinical use
pulmonary hypertension, erectile disfunction
22
Sildenafil side effects/ adverse reactions
Severe hypotension and death if combined with nitrates, dyspepsia, priapism
23
Hydralazine clinical use
Hypertension; CHF
24
Hydralazine Side effects/Adverse Reactions
Dizziness, headache, angina, tachycardia, peripheral edema; Pregnancy category C
25
Nitroglycerine + Hydralazine
decreases tolerance of NO donor
26
Hydralazine is not used for
angina; healthy artery will dialate more than injured
27
Hydralaine half life is
relatively short; making it a non ideal hypertensive
28
Calcium-Channel Blockers: Mechanisms of Action and Pharmacology
Block calcium channels
Decrease calcium influx into cells
Decrease ER/SR calcium loading
Effects depend on selectivity
29
DHPs act on
blood vessels (L type receptors)
30
non DHPs act on
heart and blood vessels (L and T type receptors)
31
DHP action
promotes diuresis; main effect on resistance arterioles, some effect on capacitance venules; some effect on kidneys
32
non DHP
decreases heart rate and force of contraction
33
DHP drugs
Amlodipine and nifedipine
34
non DHP drugs
Diltiazem and Verapamil
35
Amlodipine half life
good for hypertension treatment
36
Long-acting CCB
1st line antihypertensive; great for treating low renin producers (esp africans and elderly)
37
Dihydropyridine CCBs have less effect on exercise performance than ________ and will not affect
b-blockers; electrolytes like diuretics do
38
Long duration of CCB action provides
superior long-term outcomes (also applicable to other anti-HTN meds).
39
Typically antihypertensives will be compensated for in the body unless
more than 1 drug is used
40
Treatment of Isolated Systolic Hypertension without Other Compelling Indications
Long-acting DHP CCB (good for isolated systolic bc won't drop diastolic that much bc doesn't have direct effect on heart)
41
nonDHPs and DHPs are both useful for ______, but
angina, but non DHPs have a stonger effect (bc they have an effect on the heart)
42
non DHPs treat these types of angina
stable angina-exertion, unstable angina-plaque, variant angina-spasm
43
DHPs treat these types of angina
stable (exertion) and variant (spasm)
44
DHP interactions
beta blocker withdrawal-increased rate of contraction in heart, then CCB will increase blood flow->bad! (not as severe for non DHPs)
45
non DHPs main use
arrhythmias, also angina
46
