Antihypertensive Drugs Flashcards
stWhat is the equation for blood pressure?
Cardiac output x Systemic vascular resistance
What is a high normal BP
130-139 mm Hg/ 85-89 mm Hg
What are the 3 different types of hypertension
Essential hypertension: Sudden/spontaneous
Secondary hypertension: Caused by another condition
Malignant hypertension: Above 180/120, a medical emergency
What is the goal of antihypertensive therapy?
Reduction of cardiovascular and renal morbidity
Achieve pressure <140/90
<130/80 for diabetics
What does the parasympathetic NS stimulate
Smooth muscle, cardiac muscle, glands
What are the 7 categories of antihypertensive drugs?
Adrenergic drugs
Angiotensin-converting enzyme inhibitors
Angiotensin II receptor blockers (ARBs)
Calcium channel blockers
Diuretics
Vasodilators
Direct renin inhibitors
What does the sympathetic NS stimulate
Heart, blood vessels and skeletal muscle
What are the 5 subcategories of adrenergic drugs
Adrenergic neuron blockers (central and peripheral)
A2 receptor agonists ( central)
A1 receptor blockers (peripheral)
Beta receptor blockers (peripheral)
Combo a1 and B receptor blockers (peripheral)
Name an A2 receptor agonist and what does it do.
Clonidine is an A2 receptor agonist. Stimulates A2 adrenergic receptors in the brain which decreases sympathetic outflow in the CNS and norepinephrine production. Also reduces renin in kidneys (makes angiotensin 1)
Name a A1 receptor blocker and what does it do
Doxazosin
Blocks a1 adrenergic receptors which dilates arteries and veins resulting in decreased BP
Also increases urinary flow rates by preventing smooth muscle contraction in the bladder neck and urethra so there’s no blockage/resistance
What is doxazosin also used to treat?
BPH
Name 3 beta blockers and what do they do?
Propranolol, metoprolol, atenolol
Reduces HR and secretion of renin (makes angiotensin I)
What does long term use of beta blockers cause?
Reduced Peripheral vascular resistance
Name a dual-action a1 and beta receptor blocker and what does it do?
Labetalol
Reduces HR and is a vasodilator
What are the indications for adrenergic antihypertensives?
HTN, Glaucoma, BPH, Severe heart failure when used with cardiac glycosides and diuretics, menopausal flushing
What are adverse effects of adrenergic drugs
Orthostatic hypotension
Dry mouth
Drowsiness, sedation
Constipation
Depression
Edema
Sexual dysfunction
Bradycardia
Headaches
Sleep disturbances
Rash
Palpitations
Why are a2 receptor agonists (clonidine) not typically used as a first line of antihypertensive drugs?
High incidence of unwanted adverse effects (orthostatic hypotension, fatigue, dizziness)
Only used adjunctly with other antihypertensives when other drugs fail
What is nebivolol HCL, what does it do and what is a nursing consideration?
Beta blocker
Blocks beta receptors which causes vasodilation resulting in a decrease in Systemic vascular resistance
Do not stop abruptly, taper out over 2 weeks
What is used as a first line antihypertensive and why?
ACE inhibitors
Safe and very effective
What is the suffix for ACE inhibitors?
“pril”
Name 4 ACE inhibitors
Captopril
Enalapril
Perindopril
Ramipril
What is the MOA of ACE inhibitors
Blocks ACE which converts angiotensin 1 to angiotensin 2.
Angiotensin 2 is a potent vasoconstrictor
Prevents breakdown of bradykinin which is a vasodilator
What else can ACE inhibitors treat
Decrease SVR and preload (left ventricle volume)
Can stop progression of left ventricular hypertrophy
What are the indications for ACE inhibitors
HTN, HF, Slow progression of Left ventricular hypertrophy after myocardial infarction
Renal protection for diabetes
What are prodrugs
Prodrugs are inactive when administered and must be metabolized by the liver into an active form
How are captopril and lisinopril different from other ACE inhibitors
They can be used if a patient has liver dysfunction, unlike others that are prodrugs
How do ACE inhibitors treat HF
Prevent sodium and water reabsorption by inhibiting aldosterone secretion
Diuretic so decreases blood volume returning to the heart
Decreases preload
Decreases work required of the heart
How do ACE inhibitors provide renal protective effects?
Reduce glomerular filtration pressure
Reduce proteinuria
Prevents progression of diabetic nephropathy
What are adverse effects of ACE inhibitors?
Fatigue, dizziness, headache, impaired taste, mood changes, Dry, nonproductive cough that reverses when therapy is stopped.
Angioedema
First dose hypotension
Possible hyperkalemia
Which ACE inhibitor has the shortest half life and needs to be given the most often? How many times must be administered?
Captopril. 3 to 4 times a day
Enalapril is the only ACE inhibitor available in _____ and ____ forms
Oral and IV
What is the suffix for ARBs
“sartan”
Name 2 ARBs
Losartan
Telmisartan
What is the MOA for ARBs
Selectively block the binding of angiotensin 2 to to angiotensin 2 receptors in vascular smooth muscle and adrenal glands
Blocks vasoconstriction and the secretion of aldosterone
What is difference between ACE inhibitors and ARBs
Both well tolerated and effective
ARBs do not cause a cough
________ are better tolerated than ____________ and are associated with lower mortality after MI
ARBS, ACE inhibitors
T/F: ARBs are as effective as ACE inhibitors in treating HF and protecting the kidneys
False
What are the indications for ARBs
HTN
Adjunctive drugs for the treatment of HF
What are the adverse effects of ARBs
Upper respiratory infections, headaches, dizziness, inability to sleep, diarrhea, dyspnea, heartburn, nasal congestion, back pain, fatigue
T/F: Hyperkalemia is more likely to occur with ARBs than ACE inhibitors
False; It is less likely
What are the contraindications with losartan
Breastfeeding women
Used with caution in patients with renal or hepatic dysfunction or renal artery stenosis
How do Calcium channel blockers decrease HTN ?
Cause smooth muscle relaxation by blocking the binding of calcium to its receptors, thereby preventing contractions.
Decreases peripheral smooth muscle tone, SVR and BP
What are the indications for Calcium channel blockers
Angina
HTN
Antidysrhythmias
Migraines
Raynaud’s disease
Cerebral artery spasm prevention
Name a calcium channel blocker
Amlodipine
How do diuretics lower BP
Decrease plasma and ECF volumes.
Decreases preload, cardiac output and total peripheral resistance
Overall decreases heart workload and BP
What is the common diuretic used to treat HTN
Hydroclorthiazide
Name a vasodilator
Sodium nitroprusside
What is the MOA of vasodilators?
Direct vasodilation of arteries and/or veins
Decreases SVR
What are the indications for Vasodilators
HTN
Hypertensive emergencies
What are the adverse effects sodium nitroprusside
Bradycardia, decreased platelet aggregation, rash, hypothyroidism, Hypotension, Methemoglobinemia, Cyanide toxicity
What are the contraindications of sodium nitroprusside?
Allergy, Severe HF, Known inadequate cerebral perfusion
What is a general rule regarding patients BP and administering an antihypertensive
If apical HR <60 or systolic BP <90, hold meds and contact physician
Teach patients to______ to avoid syncope from postural hypotension.
Change positions slowly
What is a consideration for male patients on these drugs?
Impotence is an expected effect
Why shouldn’t antihypertensives be stopped abruptly
Can cause rebound hypertensive crisis which could lead to a stroke
