Cardiovascular Drugs: HTN Flashcards
Define Hypertention
systolic BP above 140 mm Hg
or diastolic BP above 90 mm Hg
Pts at risk for primary hypertention
Older adults, African Americans, Hispanic Americans, postmenopausal women, and Obese people
Primary (Essential) HTN
HTN with no identifiable cause, it is a chronic, progressive disorder. The most common form of HTN (92%)
Secondary HTN
less than 10% of pple with HTN have this form, it is elevation of BP brought on by an identifiable primary cause.
Causes of Secondary HTN
Chronic Renal Disease Renovascular disease Oral contraceptive-induced coarctation of the aorta primary aldosteronism cushing's syndrome pheochromocytoma sleep apnea thyroid or parathyroid disease
Antihypertensive Meds classes
- Diuretics
- Angiotensin Converting Enzyme Inhibitors
- Angiotensin II Receptor Blockers
- Aldosterone Antagonists
- Sympatholytics
- Direct Acting Vasodilators
- Calcium Channel Blockers
What is the first line treatment for HTN?
Diuretics and Beta blockers.
Diuretics are inexpensive and are the drug of choice for most pts.–esp for treating the elderly and African Americans
Essential HTN med
Thiazides (HCTZ)
Principal adverse effects of thiazides
- Hypokalemia (can be minimized by consuming potassium rich foods like bananas and citrus and using potassium supplements or a potassium-sparing diuretic).
- dehydration
- hyperglycemia
- hyperuricemia
When should you not use thiazides
when your GFR is low
-in this case High-ceiling (loop) diuretics may be prescribed which will lower BP be reducing blood volume and promoting vasodilation.
Adverse effects of high-ceiling (loop) diuretics such as furosemide
hypokalemia dehydration hyperglycemia hyperuricemia hearing loss
potassium-sparing diuretics (spironolactone) should not be used in combination with__________
should not be used in combination with one another or with potassium supplements
-should not be used routinely with ACE inhibitors, angiotensin II receptor blockers, or aldosterone antagonists all which promote significant HYPERKALEMIA
Sympatholytics (antiadrenergic drugs) how do they work and what are the subcategories
Suppress the influence of the sympathetic nervous system on the heart, blood vessels and other structures.
1) beta blockers
2) alpha1 blockers
3) alpha/beta blockers
4) centrally acting alpha2 agonists
5) adrenergic neuron blockers
Centrally acting alpha 2 agonist: Clonidine (catepres, catapres-TTS, Jenloga)
INDICATIONS, ACTIONS
indicated for severe pain (sold as Duraclon) and for treatment of hypertension (sold as Catapres and Jenloga)
action: alpha2 adrenergic agonist that causes “selective” activation of alpha 2 receptors in CNS-specifically in brainstem associated with autonomic regulation of the cardiovascular system. By activating central alpha 2 receptors, clonidine reduces sympathetic outflow to blood vessels and to the heart.
- alpha 2 receptors
Angiotensin Converting Enzyme Inhibitors
captopril (Capoten) benezepril (lotensin) enalapril (vasotec) fosinopril (Monopril) lisinopril ( Prinivil, Zestril) ramipril (altace) quizapril (accupril)
How do ACE inhibitors help treat diabetic pts with HTN
Lowers incidence of heart attacks and all cause mortality rates
-help slow progression of kidney disease by decreasing glomerular filtration pressure
Uses of ACE inhibitors
HTN, CHF, Post MI, LV dysfunction, nephropathy
prevention of : MI, stroke, death in pts with CV risk and decreases structural remodeling of the heart and blood vessels
Effects of ACE inhibitors
Cardiac output is increased (improved regional flow and decreased peripheral resistance) without increasing HR because ACE inhibitors do not interfere with cardiovascular reflexes
Side effects of ACE inhibitors
Cough
first dose hypotension
rash : withdraw treatment
Dysguesis (distortion of taste)-w/draw trmt
angioedema: life threatening emergency (related to elevated bradykinin)
neutropenia: rare but serious complication
ACE inhibitors are contraindicated for__________
- pts with renal failure: dont use with pt with bilateral renal stenosis, the kidneys rely on RAAS to maintain GFR
- Hyperkalemia: severe elevation of K can result in cardiac arrest. avoid us of ACE-I with K sparing diuretics or K supplements.
- pregnant women esp in 2nd and 3rd trimesters (Category D) can cause death to fetus
Name some medications that are Angiotensin II Receptor Blockers
The Sartans Losartan (Cozaar) Valsartan (Diovan) Irbesartan (Avapro) Candesartan (Atacand) Olmesartan (Benicar) Telmisartan (Micardis) Eprosartan (Teveten)
ACTION of ARBs
Blocks the action of angiotensin II by blocking its access to receptors in blood vessels, adrenals, and other tissues
Side effects of ARBs
Nasal congestion, HA, Dizziness, angioedema (incidence is lower)
- -does not produce cough or Hyperkalemia
- -no clear evidence why they decrease CV morbidity and mortality
Aldosterone Antagonists
- example of one
- action
- side effect
“Tyrone” the bouncer
-Spironolactone (Aldactone)
-excretion of sodium and water and retention of K by BLOCKING ALDOSTERONE
side effect: Hyperkalemia
Therapeutic Uses for Spironolactone
Used primarily for hypertension and edema. Most commonly used in combination with thiazide or loop diuretic to conteract the potassium wasting effects.
- HF: in pts with severe HF spironolactone reduces mortality and hospital admissions, mostly from protective effects of aldosterone blockade in the heart and blood vessels.
- also used for primary hyperaldosteronism, premenstrual syndrome, polycystic overy syndrome and acne in young women.
adverse effects of Spironolactone ( an aldosterone antagonist)
Hyperkalemia–can produce fatal dysrhythmias: if K>5 or if abnormal cardiac rhythm develop DC and restrict K intake.
- Benign and Malignant Tumors
- Endocrine Effects: structure similar to steroid hormones and can cause gynecomastia, menstrual irregularities, impotence, hirsutism and deepening of voice
Example of a Direct Renin Inhibitor
- action
- indication
Aliskiren: acts on renin to inhibit conversion of angiotensinogen to angiotensin I
- stops entire RAAS
- approved only for HTN
Side effects of DRI’s
- risk of angiodedema, cough, hyperkalemia is low
- can cause diarrhea
- reduction of negative outcomes is NOT WELL ESTABLISHED
Beta-Adrenergic Blockers
“-olol”
- metoprolol (Lopressor)
- propranolol (Inderal)
- atenolol (Tenormin)
- bisoprolol (Zebeta)
Action of Beta Blockers
blockade of B1 receptors decreases HR, AV conduction, contractility, and CO
- suppresses reflex tachycardia caused by vasodilators
- blocks B1 on juxtaglomerular cells of the kidney (reduces renin)
- reduces peripheral vascular resistance with long term (mechanism unknown)
Adverse effects effects for Beta Blockers
- increased incidence of type 2 DM with use
- masks hypoglycemia
- depression, insomnia, bizarre dreams, sexual dysfunction (risk is small)
- fatigue and lethargy MOST COMMON
- dizziness and/or lightheadedness upon standing
contraindications for B blockers
CONTRAINDICATED: in asthma, emphysema and chronic bronchitis (COPD) due to bronchoconstriction-important to use a B1 selective drug such a metoprolol.
What is rebound excitation?
when beta blockers get stopped suddenly there is an increase in cardiac activity causing anginal pain and ventricular dysrhythmis. THis is because long term use of beta blockers can sensitize heart to catecholamines.
–MUST BE WITHDRAWN slowly, angina, MI and death reported in pts who D/C treatment abruptly w/out gradual withdrawal.
Indications for Alpha Adrenergic Blockers
treat HTN also BPH (Benign Prostatic Hypertr), glaucoma, Raynaud’s disease
-used if other agents aren’t effective (high risk of stroke, CHF)
adverse effects of alpha adrenergic blockers
high risk of stroke, CHF
severe orthostatic hypotension with 1st dose
-palpitations, dizziness, HA, drowsiness, decreased energy
Examples of Alpha Adrenergic Blockers
Prazosin (minipress)
Terazosin (Hytrin)
doxazosin (Cardura)
Alpha/Beta Adrenergic Blockers: action, example drugs
Alpha1 and Beta 1 blockers
A1 blockage-vasodilation
B2 blockage-blocks Renin, decreases HR, decreases contractility
carvedilol (coreg) and labetalol (Normodyne, Trandate)
Centrally Acting Alpha2 Agonists
nervous system inhibitors
-act within brainstem to suppress sympathetic outflow to heart and blood vessels resulting in vasodilation and reduced CO
Adverse effects of centrally acting alpha 2 agonists action and examples of drugs
all cause dry mouth and sedation
Clonidine (Catapres) : severe rebound hypertension of abruptly d/c
Methyldopa: hemolytic anemia, liver disorders
Adrenergic neuron-blocking drugs
decrease release of norepinephrine from postganglionic sympathetic neurons
- decreases activation of all adrenergic receptors
- example: Reserpine
Reserpine: indication, adverse effect
the primary indication: HTN
adverse effect: depression (depletes transmitters such as serotonin and catecholamines from neurons in CNS)
-NOT a preffered drug because of severe adverse effects and more desirable drugs available
Direct Acting Vasodilators
action
indications
may act on arterioles, veins or both
indication HTN, angina, HF
side effects of Direct Acting Vasodilators
- risk of orthostatic hypotension is low
- lowers BP-which may cause tachycardia, renin release and fluid retention
examples of direct acting vasodilators
Hydralazine (apresoline)
minoxidil (Loniten)
Hydralazine (apresoline) uses and side effects
a direct acting vasodilator
direct acting vasodilator, used for essential HTN, hypertensive crisis and HF
serious side effects: systemic lupus erythematosus-like syndrome (rare)
–charactarized by muscle pain, joint pain, fever, nephritis and pericarditis
–DC drug; may take 6+ months to resolve
Minoxidil (Loniten)
indication and side effects
(a direct acting vasodilator)
indication: severe HTN
side effects: ECG changes (T-wave), peripheral edema, pericardial effusion with tamponade
-hypertrichosis (excessive hair growth)
-not routinely used because of risk of harm to pts
Sodium nitroprusside (Nitropress) (potent direct-acting vasodilator)
used for hypertensive crisis
(in ICU)–to monitor BP, slow IV infusion.
-causes both venous and arterial dilation
What drug causes Cyanide poisoning with overdose?
Sodium Nitroprusside (Nitropress) a direct acting potent vasodilator.
must stop IV infusion, use buffers, infuse THIOSULFATE
may need hemodialysis.
How do Calcium Channel Blockers compare against other antihypertensive drugs to decrease CV disease incidence and mortality
-promote dilation of ARTERIOLES
have immediate effect on BP (but are inferior in preventing heart events, stroke or kidney complications)
action of calcium channel blockers
prevent calcium ions from entering cells
- vascular smooth muscle
- works on heart and blood vessels by regulating strength and rate of heart
indications for Calcium Channel Blockers
Used to treat HTN, Angina, Cardiac dysrhythmias (atrial fibrillation)
side effects of calcium channel blockers
dizziness
HA, flushing
Peripheral edema (r/t vasodilation effects)
impotence, gingivitis
examples of calcium channel blockers
verapamil (Calan), Diltiazem (Cardizem)
Nifedipine (Procardia)
Dihydropyridines: act mostly on vascular smooth muscle
promotes vasodilation
produces little blockade of calcium channels in heart
adverse effects with Nifedipine
causese reflex tachycardia (occurs primarily with fast acting, not sustained release)
- -often combined with beta blocker to suppress reflex tachycardia
- -the rapid acting: assoc. with incr. mortality in pt with MI, unstable angina–should be used with caution
