(04-05-17) Cardiovascular Drugs Flashcards
underlying defect is a failure in the regulation of vascular resistance
hypertension
*defined as TWO BP readings of at least 140/90 separated by 2 minutes on 2 or more visits
what is systolic BP
pressure at peak of left ventricular contraction
what is diastolic BP?
resting resistance of the arterial system
what is the prevalence of HTN?
20-30% of all adults (more than 50 mill)
-1 in 4 pts in teh US have HTN
what % of pts with HTN are not being treated?
46.4%
what % of the pts that are being treated for HTN are adequately controlled?
49%
compromises 90-95% HTN pts
- precise etiology is unknown
- older pts
primary HTN
other 5-10% of pts with HTN
- there is some underlying condition
- often younger pts
- –renal, endocrine, neurologic disorders
secondary HTN
what are the #’s for normal HTN?
less than 120 / less than 80
what are the #’s for pre-HTN?
120-139 / 80-89
what are the #’s for stage one HTN?
140-159 / 90-99
what are the #’s for stage two HTN?
greater than 60 / greater than 100
what is considered an URGENCY with HTN?
- systolic is greater than 180
- diastolic is greater than 110
what is considered an EMERGENCY?
- same as with urgency but now with evidence of end-organ damage
- -confusion
- -chest pain
- -renal failure
- -visual changes
what are the benefits of treatment of HTN?
- reduces incidence of stroke
- dec MI
- dec CHF
- reduciton of 12mm HG in SBP for ppl instage 1 HTN over a 10 year period in prevention of 1 death in 11 pts treated
what are the goals of tx of HTN?
- limit end-organ damage
- most adults less than 140/99 mmHG
- diabetes or renal disease less than 130/80 mmHg
what are the ways to treat HTN?
- ALWAYS start with lifestyle modifications (weight loss, red sodium, aerobic exercise, dec alcohol intake, stop smoking)
- MOST pts require pharmacologic treatment
- MOST require more than one agent to achieve goals
what are the 5 common anti-hypertensive groups?
- diuretics
- adrenergic agents
- CCBs
- ACEIs
- ARBs
what are the steps to treating HTN pharmacologically?
- diuretic, beta blocker, ACEI/CCB. Thiazide is preferred
- after 1-3 months, inc the dose, add a different class, or substitute another drug
- add a 3rd drug, discontinue the 2nd drug, and substitute another
- add a 3rd and 4th drug
what is the mechanism of thiazide diuretics?
- dec CO (by reducing plasma volume)
- dec peripheral resistance (red Na-Ca exchange)
where do thiazide diuretics work?
distal convoluted tubule
what are the adverse effects of thiazide diuretics?
- hypokalemia (tired, lethargic, weakness)
- xerostomia
- anorexia
*all bc it basically drains your system of water
why are loop diuretics considered the “strong cousin” of thiazide diuretics?
bc they act the same way just in a different part of the body
- ASCENDING LOOP OF HENLE
- inhibits reabsorption of Na with concurrent loss of fluids
what is the most commonly used loop diuretic?
furosemide (lasix)
what are the adverse reactions of loop diuretics?
- hypokalemia
- hyperuricemia
- mostly used in pts with CHF
- can also be used if rapid diuresis is desired
-diuretics involvoing “potassium -catching” ability
potassium sparing diuretics
*used as adjunctive therapy with other drugs
what pt populationare potassium sparing diuretics good for?
pts concerned about UNWANTED HYPOKALEMIA
what is the mechanism of potassium sparing diuretics?
- competitive ANTAGONISTS compete with aldosterone
- directly block Na channels
where do potassium sparing diuretics work ?
DCT and collecting duct
what are the adverse reactions of potassium sparing diuretics?
- hyperkalemia
- arrhythmia
what are the receptors for the adrenergic agents for HTN?
- alpha 1 = inc BP
- alpha 2 = stimulation inhibits norepi
- beta 1 = inc HR and contraction
- beta 2 = inc contraciton and CO (not as strong as beta 1)
what are the medication mechanisms for adrenergic agents of HTN?
- alpha 2 agonists
- alpha 1 antagonists
- non-selective beta 1 and beta 2 antagonists
- beta 1 antagonists
what is the mechanism of alpha 1 antagonists?
- block receptors in arteries and veins therefore relaxing smooth muscle associated with these
- not typically used drug for HTN, can use in CONJUNCTION with BPH
what are the side effects of alpha 1 antagonists?
postural hypotension
what is the mechanism of alpha 2 agonists?
- inhibition action of epi and norepi
- leads to vessel dilation
- NOT FIRST LINE, usually 3rd or 4th
what are the side effects of alpha 2 agonists?
drowsiness, sedation
why do beta blockers help asthema?
bc they lead to bronchial dilation
what pts are NON-SELECTIVE beta blockers bad for?
pts with reactive airway disease
what pts are SELECTIVE (B1 only) good for?
-ischemic heart disease pts and MI
-
what is the disadvantage to selective B1 blockers?
- hypotention
- bradycardia
- these drugs have the suffix -dipine
- used to treat HTN and other cardiac conditions such as arrhythmias and angina
Calcium channel blockers
what is the mechanism for calcium channel blocker?
- inhibit the movement of calcium into cardiac cells
- produces vasodilation and reduces afterload
how does the CCB, dihydropyridine work?
reduce vascular resistance = dilation
how does the CCB, NON-dihydropyridine work?
reduce myocardial O2 demand = treat angina
what are the adverse reactions of CCB?
- gingival overgrowth
- excessive HYPOtension (dizziness, syncope)
- nausea and vomitting
- bradycardia
what is the mechanism of ACE inhibitors?
block conversion of angiotensin I to II in order to reduce BP
where do ACE inhibitors work?
KIDNEY
-the renin-angiotension system
what are the adverse effects of angiotension converting enzyme inhibitors
- hypotension (dizziness and syncope)
- URI - dry cough
- N&V
- lichenoid oral lesions
- avoid NSAIDS during drug action
what is the mechanism of angiotension receptor blockers?
attach to the angiotension II receptor and block the effect of angiotension II
what is the prototype of angiotension receptor blockers?
losartan (cozaar)
what are the adverse reactions of angiotension receptor blockers>
ARBs are more specific than ACEIs and expected to have FEWER adverse reactions
-can include: dizziness, fatigue, insomnia, headache, URI, diharrea, angioedema
what are the most common meds for each of the treatments of HTN?
- thiazide = HCTZ
- ACEI = lisinopril
- Beta-blockers = metoprolol
- CCBs = amlodipine
what is the cut off for BP reading for tx in the CCC
for EMERGENCIES
less than 180/110
how does the med plavix (clopidogrel) work after MI and stent placement?
- anti-platelet that inc bleeding time
- prevents fibrinogen binding and dec platelet aggregation and adhesion
- platelet turn around is 5-9 days
how does the med plendil (felodipine) work after MI and stent placement?
- CCB
- produces relaxation of coronoary smooth muscle and vasodilation
- inc myocardial oxygen delivery
how does the med nitrostat work after MI and stent placement?
- nitroglycerine - peripheral vasodilator
- dec workload of the heart
what meds would a pt be on if they have a bare metal stent?
-aspirin and plavix for a month after procedure
how does a drug eluting stent work?
- stent witha drug to block cell proliferation
- possibly dec stent re-stenosis
how do you prevent re-stenosis for a bare metal stent
-dual platelet therapy for at least a month (ideally for a year)
how do you prevent re-stenosis for a drug eluting stent?
-dual platelet therapy for at least 6 months, ideally for a year
mismatch between O2 needs of the heart and delivery of O2 to the heart
-relieved by O2, rest, and vasodilators
angina
what is the treatment of angina?
- stop procedure
- position upright (trendellenburg if SBP less than 100)
- 100% O2
- sublingual nitro 0.4 mg
- morphine for pain relief
what are the best anti-anginal drugs?
- nitro (by far most common)
- CCBs
- B-adrenergic blocking agents
how does the most common anti-anginal drug nitro work?
- vasodilator
- activates guanyly cyclase and inc cGMP producing relaxation of vascular smooth muscle
- reduces workload of the heart, also reduces O2 needs
what are the adverse reactions of nitro?
- severe headaches
- flushing, hypotension, light-headedness, syncope
- burning/tingling
ischemia leading to death of myocardial tissue
-NOT RELIEVED by O2, rest, and vasodilators
MI
*GET PT TO HOSPITAL
complex disease proces by which heart is unable to fill with or eject blood to meet bodily needs
- ischemic heart disease
- valvular heart disease
- hypertension
CHF
what side of the heart is responsible for systemic heart failure?
right
what side of the heart is responsible for pulmonary congestion?
left
what are the classes for CHF?
- symptomatic only with greater than normal activity
- symptomatic only with ordinary activity
- symptomatic with minimal activity
- symptomatic at rest
what is the number one treatment option for CHF?
digoxin
*still not considered first line therapy though
what is the mechanism of digoxin in the treatment of CHF?
- inc force and strength of contraction of the myocardium
- allows the heart to do more work without inc the use of O2
- the heart becomes more efficient, and CO inc
what are the adverse reactions fo digoxin?
narrow therapeutic index so slight changes can lead to bad things
- arrythmias
- visual changes
- N&V
- headaches
what are the first line therapy for CHF>
ACEIs
occurs when multiple areas within the atria depolarize, causing a quivering of the atrium. AV node sporadically reacts leading to rate in the 180s
atrial filibration
*quivering of the heart allows for thrombus formation
what is the inc in risk of CVA in pts with atrial filibration?
7x
how do antiarrhytic agents work?
depressing parts of the heart that are beating abnormally
- dec velocity of depolarization
- dec propagation
- inhibit aberrant impulse propagation
what are the adverse rxns of antiarrhythmic agents?
- these have a NARROW THERAPEUTIC INDEX so they are difficult to manage
- only used for pts with arrhymias that prevent the proper functioning of the heart
elevations in cholesterol and/or triglycerides and is associated with the development of arteriosclerosis
hyperlipidemia
what is the first line of defense when it comes to hyperlipidemia>
lifestyle changes
- inc exercise
- dec saturated fat in diet
- dec cholesterol from the diet
what are the drugs that are included in antihyperlipidemics?
- HMG CoA reductase inhibitors (STATINS)
- inhibitors of intestinal absorption of cholesterol
- gemfibrozil
- niacin
how do the “statin” drugs work?
lower cholesterol levels by inhibiting HMG CoA reductase, the rate limiting enzyme in cholesterol synthesis
what are the adverse effects of “statins”
- GI complaints
- muscle pain
- skin rash
- CAN INC ANTICOAGULANT EFFECTS OF WARFARIN
what is ezetimibe (zetia)?
-inhibitors of intestinal absorption of cholesterol
what are the adverse reactions of zetia?
- fatigue
- abdominal pain
- diarrhea
how does gemfibrozil (lopid) work?
- used when triglycerides are elevated
- incs lipolysis of trigylcerides, decreasing lipolysis in adipose tissue, and inhibiting secretion of VLDLs from the liver
what are the adverse rxns of gemfibrozil?
- promote gallstone formation
- taste preversion and hyperglycemia
what % of ppl with aortic stenosis will die if valve is not replaced in 3 years?
75%
what is the treatment of aortic stenosis?
coumadin
- commonly used for pts with sick sinus syndrome
- tx for long-term bradycardia
- can be used for atrium, ventricle, or both
pacemaker
how do Implated Cardiovascular Defilibrators (ICDs) work?
provide a shock wihthin 15 seconds of sensing a dysrhythmia
