Beta Blockers, Alpha Blockers, Alpha Stimulants, Emergencies, & Urgencies Flashcards
What are the sympathetic effects on alpha 1 receptors?
Vasoconstriction
Increased peripheral resistance
Mydriasis
Increased closure of internal sphincter of the bladder
What are the big differences in the beta blockers?
Selectivity
How do non-selective beta-blockers work?
Block both beta-1 and beta-2 receptor sites.
How do selective beta-blockers work?
Specifically block beta-1 receptors.
What is an example of a non-selective beta blocker?
Propanolol
What is an example of a selective beta-blocker?
metroprolol
How do beta-blockers with peripheral vasodilatory effects work?
Adds in an alpha-1 blockade effect.
Affects nitric oxide levels.
What is an example of a beta-blocker which adds an alpha-1 blockade effect?
Labetolol
Carvedilol
What is an example of a beta-blocker that affect nitric oxide levels?
nebivolol
What are the sympathetic effects of alpha-2 adrenoreceptors?
Inhibition of norepinephrine release
Inhibition of acetylcholine release
Inhibition of insulin release
What are the sympathetic effects of beta-1 adrenoreceptors?
Tachycardia
Increased lipolysis
Increased myocardial contractility
Increased release of renin
What are the sympathetic effects of beta-2 adrenoreceptors?
Vasodilation Slightly decreased peripheral resistance Bronchodilation Increased muscle and liver glycogenolysis Increased release of glucagon Relaxed uterine smooth muscle
Why do people use metroprolol, labetolol, and carvedilol?
Decreased mortality found in clinical studies.
How can we affect blood pressure within the sympathetic nervous system?
Blocking the beta-1 receptors.
Blocking peripheral alpha-1 receptors.
Trigger central alpha-2 receptors
How does blockade of the beta-1 receptors reduce blood pressure?
Reduce heart rate
Reduce renin release
How does blockade of the alpha-1 receptors reduce blood pressure?
Vasodilation
Decreased peripheral resistance
How does triggering central alpha-2 receptors affect blood pressure?
Reduces sympathetic outflow to the heart.
How do beta blockers work?
Activation of beta-1 adrenoreceptors on the heart
Decreased cardiac output
Decreased Renin > Decreased angiotensin II > Decreased peripheral resistance
Decreased aldosterone > Decreased sodium and water retention> decreased blood volume
*Decrease in blood pressure!
What is an example of a non-selective beta blocker?
Carvedilol
Labetalol
Propanolol
What is an example of a selective beta blocker?
Metroprolol
Nebivolol
Who are the candidates for use of beta blockers?
Younger patients!
Higher cardiac output and cardiovascular system efficiency.
What is the effectiveness of beta blockers?
No evidence for primary prevention of hypertension.
What are the preferred HTN agents for patients with cardiovascular disease?
beta blockers
At what creatinine clearance do beta-blockers eliminated renally need dose adjustments?
35 ml/min
What is a beta blocker which is eliminated renally?
Atenolol
What is the half life of atenolol?
6-8 hours
Therefore dosed twice per day for clinical effectiveness.
What adjustments need to be made for beta blockers metabolized hepatically?
No renal dose adjustment but first pass effect issues.
What is a beta blocker affected by hepatic metabolism?
Metoprolol
Carvedilol
What are the indications for Atenolol?
Treatment of HTN alone or in combination with other agents.
Management of angina pectoris.
Secondary prevention postmyocardial infarction.
What are the indications for Carvedilol?
Management of HTN.
Mild-to-Severe heart failure of ischemic or cardiomyopathic origin.
Left ventricular dysfunction following myocardial infarction (clinically stable with LVEF < or = to 40%.
How do you adjust the dose of Atenolol for renal impairment?
Dose once per day.
What are the indications for metroprolol succinate?
Treatment of hypertension.
Treatment of angina pectoris.
To reduce mortality/hospitalization in patients with heart failure (stable NYHA Class I or III) already receiving ACE inhibitors, diuretics, and/or digoxin.
What is the brand name for Carvedilol?
Coreg
Coreg CR
What is the brand name for Metroprolol succinate?
Toprol XL
What is the brand name for Nebivolol?
Bystolic
What are the indications for nebivolol?
Treatment of hypertension alone or in combination with other agents.
What are the adverse effects of beta blockers?
Many side effects on cardiac tissue:
- Bradycardia
- Hypotension
- Atrioventricular nodal conduction block
Bronchoconstriction
Hypoglycemia
Are beta blockers contraindicated in controlled asthma or controlled COPD?
No
Metroprolol Ext. Rel
100 mg
One tablet daily
Carvedilol
12.5 mg
One tablet twice a day
Why should you watch a diabetic on a beta blocker?
Beta blockers can mask the symptoms of diabetes.
Decrease heart rate.
Bystolic
20 mg
One tablet daily
What are the beta blockers to use?
Metroprolol
Carvedilol
Bystolic
What is the extended release of Metroprolol?
Metroprolol succinate
What does the lipid and water solubility of beta bockers determine?
the degree of penetration of the blood-brain barrier.
What is the max dosing of metroprolol extended release?
400 mg
Theoretically, what effects can beta blockers have on the central nervous system?
Lethargy
Nightmares
Confusion
Depression
What are the characteristics of water soluble beta blockers?
Less tissue penetration
Longer biological half-lives
Coreg CR
25 mg
One tablet per day
What is the mechanism of action for alpha blockers?
Block peripheral post synaptic adrenergic receptors resulting in arterial/venous vasodilation.
How long do you continue beta-blocker therapy before determining the effectiveness of therapy?
4-6 weeks
What are the adverse drug reactions of alpha blockers?
first dose syncope
peripheral edema
How do alpha blockers work?
Affect both arteriolar and venous resistance of vessels.
Dependent on the magnitude on sympathetic system activity.
What can be the body’s blood pressure response to alpha-1 blockade?
Increase in heart rate
Increase in cardiac output
Increased fluid retention
Which alpha blocker has the longest half life of the hypertension agents?
Doxazosin
What are the three alpha blockers?
Prazosin (Minipress)
Terazosin (Hytrin)
Doxazosin (Cardura)
What are the indications for Prozasin?
Treatment of hypertension.
What are the indications for Terazosin?
Management of mild-to-moderate hypertension alone or in combination with other agents such as diuretics or beta-blockers.
Benign prostate hyperplasia.
What are the indications for doxazosin?
Treatment of hypertension as monotherapy or in conjunction with diuretics, ACEI, beta-blockers, or calcium antagonists.
Treatment of urinary outflow obstruction and/or obstructive or irritative symptoms associated with benign prostate hyperplasia.
Commercial name for Prozasin
Minipress
Commercial name for Terazosin
Hytrin
Commercial name for Doxazosin
Cardura
What are the adverse drug reactions of alpha blockers?
Orthostatic hypertension - increased fall risk. Easing into therapy or dose changes.
Aggravators - nasal congestion, headache, reflex tachycardia, peripheral edema.
Non-selective alpha blockade - smooth muscle of the base of the urinary bladder
Doxazosin
8 mg
One capsule daily
What is an example of an alpha blocker to remember?
Doxazosin
Do alpha blockers have a favorable effect on lipid profile?
Diminish risk of atherosclerosis by this mechanism and reduction of effect of cathecholamines in stimulation of vascular smooth muscle hypertrophy
What is the maximum dose for doxazosin?
> 16 mg per day
Where do alpha stimulants work?
The brain
How do alpha stimulants work?
Block signals out of the central nervous system.
What are the alpha stimulants?
Methyldopa
Clonidine
Guanfacine
Guanabenz
What are the indications for Methyldopa?
Management of moderate-to-severe hypertension.
What are the indications for Clonidine?
Management of hypertension (monotherapy or as adjunctive therapy).
Tablets or patch
What are the indications for Guanfacine?
Management of hypertension.
What are the indications for Guanabenz?
Used alone or in combination with other classes of antihypertensive agents in the management of hypertension.
Commercial name for Methyldopa
Aldomet
Commercial name for Clonidine
Catapres
Commercial name for Guanfacine
Tenex
What are the adverse drug reactions for alpha stimulants?
dry mouth
bradycardia
orthostatic hypotension
sedation
What are alpha stimulants also used for?
Addiction treatment
Clonidine: Psychosis, Restless Leg Syndrome, Ulcerative colitis
What can occur with abrupt withdrawal of an alpha stimulant?
Life-threatening hypertensive crisis
Do alpha stimulants have metabolic effects of beta blockers and thiazides?
No!
Clonidine
200 mcg
one tablet twice a day
What are the alpha stimulants to remember?
Clonidine
Catapres TTS
Methyldopa
Catapres TTS
0.2 mg/ 24 hours
apply one patch once every 7 days
Methyldopa
500 mg
one tablet twice per day
Minoxidil
5 mg
one tablet daily
What is an example of a direct vasodilator?
Minoxidil
Hydralazine
How does Minoxidil work?
Increase in nitric oxide levels.
Increaed nitric oxide = increased vasodilation = decreased blood pressure
What are the adverse drug reactions of Minoxidil?
Standard side effects for an antihypertensive
Pericarditis and pericardial effusion that could progress to tamponade.
Increase oxygen deman and exacerbation of angina.
Some sodium and water retention.
Anti-hypertensive agent used in pregnancy
Methyldopa
or
beta blocker
How does Hydralazine work?
Opening up potassium channels in vascular smooth muscle.
Increased nitric oxide levels.
When can you write for Minoxidil?
After you’ve used 3 antihypertensive agents and still have not met goal of therapy.
What is Minoxidil also known as?
Rogaine
Hydralazine
50 mg
one tablet twice a day
Initially 4 times per day until maintenance is achieved.
Why must you give a beta blocker to blunt the effect of Hydralazine?
blood pressure drops significantly enough to cause reflex tachycardia.
What are the adverse drug reactions of hydralazine?
Headache
Lupus-like syndrome
What is the half life of hydralazine?
Short!!
Frequent daily doses.
No extended release form.
hypertensive emergencies
severe elevations in blood pressure
often higher than 220/140 mmHg
What does a hypertensive emergency require?
requires immediate attention and blood pressure reduction
hypertensive emergency
marked elevation in blood pressure
usually higher than 180/110 mmHg
What are the signs and symptoms of hypertensive urgency?
headache
SOB
pedal edema
How is a hypertensive urgency handled?
oral agents
What oral drugs are appropriate for hypertensive emergency?
Captopril
Clonidine*
Labetalol
Amlodipine
What injectable drugs are appropriate for hypertensive emergency?
sodium nitroprusside nitroglycerin nicardipine hydralazine enalaprilat labetalol esmolol
sodium nitroprusside
0.25-10 mcg/kg/min IV infusion
onset/duration of sodium nitroprusside
Immediate/ 2-3 min after infusion stop
ADR of sodium nitroprusside
nausea
vomiting
cyanide poisoning
nitroglycerin
5-100 mcg IV infusion
onset/duration of sodium nitroprusside
2-5 min/ 5-10 min after infusion stop
ADR of nitroglycerin
headache
tachycardia
What is sodium nitroprusside?
a powerful intravenous vasodilator.
What does sodium nitroprusside dilate?
arterial and venous vessels
sodium nitroprusside toxicity causes…
hypotension
metabolic acidosis
arrhythmias
death
What limits the extent of your ability to prescribe injectable vasoactive products?
state laws and regulations
True or False: You are limited by state laws, regulations, etc as to the extent of your ability to prescribe oral vasoactive agents.
False!
hypertensive emergencies caused by acute coronary syndrome are treated with…
Nitroglycerin
Nitroprusside
Nicardipine
hypertensive emergencies caused by heart failure are treated with…
Nitroprusside
Nitroglycerin
IV loop diuretic
What is the goal of therapy in a hypertensive emergency?
20-25% reduction from starting pressure in 1-3 hours
hypertensive emergencies caused by acute or chronic renal failure are treated with…
Nitroprusside
Labetalol
Nicardipine
hypertensive emergencies caused by ischemic stroke are treated with…
Nitroprusside
Nicardipine
Labetalol
oral agents used to treat hypertensive emergencies include
Captopril
Clonidine
Labetalol
Amlodipine
Captopril
25 mg PO, repeat as needed
SL - 25 mg
onset/duration of Captopril
PO: 15 - 30 minutes / 6-8 hours
SL: 10-20 min / 2-6 hours
ADRs of Captopril
hypotension
renal failure
bilateral renal stenosis
Clonidine
0.1 - 0.2 mg PO
repeat hourly as required to total dosage of 0.6 mg
onset/duration of Clonidine
30-60 minut / 8-16 hours
ADRs of Clonidine
hypotension
drowsiness
dry mouth
Labetalol
200 - 400 mg PO
repeat every 2-3 hours
onset/duration of Labetalol
1-2 hours/ 2-12 hours
ADRs of Labetalol
bronchoconstriction
heart block
orthostatic hypotension
Amlodipine
2.5 - 5 mg PO
onset/duration of Amlodipine
1-2 hours / 12-18 hours
ADRs of Amlodipine
tachycardia
hypotension
injectable agents for hypertensive emergencies
Nicardipine Hydralazine Enalaprilat Labetalol Esmolol
Nicardipine
5-15 mg/hr IV infusion
onset/duration of Nicardipine
1-5 min / 15 - 30 min
ADRs of Nicardipine
tachycardia
nausea
increased intracranial pressure
Hydralazine
5-20 mg IV bolus;
10 - 40 mg IM
repeat every 4-6 hours
onset/duration of Hydralazine
10 min/ 1 hr IV 20-30 min / 4-6 hr IM
ADRs of Hydralazine
tachycardia
headache
aggravation of angina
Enalaprilat
0.625-1.25 mg every 6 hr IV
onset/duration Enalaprilat
within 30 min / 12-24 hours
ADRs of Enalprilat
renal failure in bilateral renal stenosis
Labetalol
20 - 40 mg IV bolus every 10 min; up to 2 mg/min IV infusion
onset/duration Labetalol
5-10 min / 2-6 hours
ADRs of Labetalol
bronchoconstriction
heart block
bradycardia
Esmolol
500 mcg/kg IV bolus; 50-100 mcg/kg/min IV infusion
onset/duration Esmolol
1-5 min/ 15-30 min
ADRs of Esmolol
first-degree heart block
heart failure
worsen asthma symptoms
