Chap 22 Antihypertensive Drugs Flashcards
AdrenergicDrugs:interactions
Can cause additive CNS depression
with alcohol, benzodiazepines,
opioids
Peripherally Acting Alpha1 Blockers
Doxazosin, prazosin, and
terazosin
◦ Block alpha1-adrenergic receptors
◦ When alpha1-adrenergic receptors
are blocked, BP is decreased.
◦ Dilate arteries and veins
◦ Alpha1 blockers also increase
urinary flow rates and decrease
outflow obstruction by preventing
smooth muscle contractions in the
bladder neck and urethra.
◦ Use: benign prostatic hyperplasia
(BPH*
Beta
Blockers
Propranolol, metoprolol, and atenolol
◦ Reduction of the heart rate through
beta1 receptor blockade
◦ Cause reduced secretion of renin
◦ Long-term use causes reduced
peripheral vascular resistance.
Beta Blockers site of action 1H 2L
Beta-1 = 1 heart
Beta-2 = 2 lungs
Adrenoceptors: vasomotor fxn AC-BD
Alpha=Constrict
Beta=Dilate
Beta Blockers: B1 selective vs. B1-B2Nonselective
A->N O->Z
A through N B1 selective: Acebutalol, Atenolol, Esmolol, Metoprolol
O through Z: B1, B2 non-selective: Pindolol, Propanalol, Timolol
Angiotensin-Converting Enzyme (ACE) Inhibitors
Large group of safe and effective drugs
Currently are 10 ACE inhibitors
Often used as first-line drugs for HF and hypertension
May be combined with a thiazide diuretic or CCB
Angiotensin-Converting Enzyme (ACE) Inhibitors
Captopril (Capoten)
Benazepril (Lotensin)
Enalapril (Vasotec)
Fosinopril (Monopril)
Lisinopril (Prinivil)
Moexipril (Univasc)
Perindopril (Aceon)
Quinapril (Accupril)
Ramipril (Altace)
Trandolapril (Mavik)
ACE Inhibitors: Mechanism of Action
Inhibit ACE inhibit an enzyme
ACE: converts angiotensin I (AI) (formed through the action of renin) to angiotensin II (AII)
A II: potent vasoconstrictors that induce aldosterone secretion by the adrenal glands
Aldosterone: stimulates sodium and water resorption, which can raise BP
Renin-angiotensin-aldosterone system (R-A-A)
ACE inhibitors thus lower BP.
Cardio Protective and Renal Protective Effects
ACE inhibitors decrease SVR (a measure of afterload) and preload.
Used to prevent complications after MI
ACE inhibitors have been shown to decrease morbidity and mortality in patients with HF.
*ACE inhibitors: reduce glomerular filtration pressure *
Standard therapy for diabetic patients to prevent the progression of diabetic nephropathy
ACE Inhibitors: Adverse Effects
Dry, nonproductive cough, which reverses when therapy is stopped
Note: First-dose hypotensive effect may occur.
CAPTOPRIL
*Cough
*Angioedema
*Potassium Excess
Taste Changes
*Orthostatic Hypotension
Pressure Drop
Renal Failure/Rash
Indomethacin Inhibition
Leukopenia
ACE drug Interactions
NSAIDs
Lithium*
Potassium sparing diuretics*
Other antihypertensives
Ace Inhibitors Interactions & Precautions
Drug interactions:
NSAIDS(decrease BP control)*
Diuretics ( excessive hypotensive effect)*
Potassium supplement (increased rick of hyperkalemia)*
Lithium ( increased lithium serum levels)*
Precautions
“first dose effect” severe hyptoension, remain in bed for 3-4 days to prevent falls
obtain BP before giving, hold if hypo
change positions slowly due to orthostatic
monitor liver and kidney fxn
Captopril (Capoten) Uses
Uses: prevention of ventricular remodeling after MI; reduce the risk of HF after MI
Shortest half-life
Must be administered multiple times throughout the day
Captopril and Lisinopril are not prodrugs
Angiotensin II receptor blocker “sartan”
Losartan
Valsartan
Candesartan
Eprosartan
Olmesartan
Losartan (Cozaar)
Beneficial in patients with hypertension and HF
Used with caution* in patients with renal or hepatic dysfunction and in patients with renal artery stenosis
Not safe for breastfeeding women and should not be used in pregnancy
Losartan Mnemonic Side Effects
Low Blood Pressure
Other(Fatigue, Headache, Dizziness)
Swelling
Allergic Reaction
Raised Potassium
Teratogenic
Acute Kidney Injury
Nasal Congestion
Calcium Channel Blockers: Mechanism of Action
Primary use: HTN and angina
Cause smooth muscle relaxation by blocking the binding of calcium to its receptors, preventing muscle contraction
Results in:
Decreased peripheral smooth muscle tone
Decreased SVR
Decreased BP
Calcium Channel Blockers: Indications
Dihydropyridine* – Amlodipine, Nicardipine Nimodipine
Non-dihydropyridine* – Verapamil, Diltiazem
Angina
Hypertension: amlodipine (Norvasc)
Dysrhythmias
Migraine headaches
Raynaud’s disease
Prevent the cerebral artery spasms after subarachnoid hemorrhage: nimodipine
Diuretics
First-line antihypertensives in the JNC 8 guidelines for the treatment of hypertension
Decrease* plasma and extracellular fluid volumes*
Results
Decreased preload
Decreased CO*
Decreased total peripheral resistance*
Overall effect
Decreased workload of the heart and decreased BP*
Thiazide* diuretics* are the most commonly* used diuretics for hypertension.*
Vasodilators
Diazoxide (Hyperstat)
Hydralazine (Apresoline)
Minoxidil (Rogaine) - hair regrowth
Nitroprusside (Nitropress)
Vasodilators: Indications
Treatment of hypertension
May be used in combination with other drugs
Sodium* nitroprusside* and IV* diazoxide* are reserved* for the management of hypertensive emergencies.
Vasodilators Nursing Implications
Before beginning therapy, obtain a thorough health history and head-to-toe physical examination
Assess for contraindications to specific antihypertensive drugs.
Assess for conditions that require cautious use of these drugs.
Educate patients about the importance of not missing a dose and taking the medications exactly as prescribed.*
Instruct patients to check with their physicians for instructions on what to do if a dose is missed; patients should never double up on doses if a dose is missed.
Monitor BP during therapy; instruct patients to
keep a journal of regular BP checks.
Instruct patients that these drugs should not be stopped abruptly because this may cause a rebound hypertensive crisis and perhaps lead to stroke.
Oral forms should be given with meals so that absorption is more gradual and effective.
Administer IV forms with extreme caution and use an IV pump.
Remind patients that medication is only part of therapy. Encourage patients to watch their diet, stress level, weight, and alcohol intake.
avoid smoking and eating foods high in sodium.
Encourage supervised exercise.
change positions slowly to avoid syncope from postural hypotension.
report unusual shortness of breath; difficulty breathing;* swelling* of the feet, ankles, face, or around the eyes; weight gain or loss; chest pain; palpitations; and excessive fatigue.
Male patients who take these drugs may not be aware that impotence is an expected effect, and this may influence compliance with drug therapy.
If patients are experiencing serious adverse effects or if they believe the dose or medication needs to be changed, they should contact their physicians immediately.
Hot tubs, showers, or baths; hot weather; prolonged sitting or standing; physical exercise; and alcohol ingestion may aggravate low BP, leading to fainting and injury; patients should sit or lie down until symptoms subside.
Patients should not take any other medications, including over-the-counter drugs, without first getting the approval of their physicians.
Educate patients about lifestyle changes that may be needed.
Weight loss
Stress management
Supervised exercise
Dietary measures
Monitor for adverse effects
(dizziness, orthostatic hypotension, fatigue) and for toxic effects.
Monitor for therapeutic effects
