Cardiovascular Drugs Flashcards
Review:
What is the Circulatory System?
- delivery of oxygen, nutrients, hormones, electrolytes, and other essentials to cells and
-removal of carbon dioxide and metabolic wastes from cells. In addition, the system helps fight infection.
Review:
What are the parts of the Circulatory System and its function?
- The heart - is the pump that moves blood through the arterial tree.
- Arteries - transport blood under high pressure to tissues.
- Arterioles are control valves that regulate local blood flow.
- Capillaries are the sites for the exchange of fluid, oxygen, carbon dioxide, nutrients, hormones, and wastes.
6 Venules collect blood from the capillaries.
7 Veins transport blood back to the heart. In addition, veins serve as a major reservoir for blood.
Review:
What are the determinants of Cardiac output?
- HEART RATE - controlled by the Autonomic Nervous System
- STROKE VOLUME – determined by;
2.1) myocardial contractility (force with which the ventricles contract),
2.2) cardiac afterload,
2.3) cardiac preload - PRELOAD – the amount of tension (stretch) applied to a muscle before contraction = force of the venous return
- AFTERLOAD – load against which a muscle exerts its force = arterial pressure that the left ventricle
overcomes to eject blood
What is hypertension?
- Defined as a persistent systolic pressure of greater than 140mmHg and/or a diastolic pressure of greater than 90mmHg
*Major risk factor for Coronary artery disease (CAD), Cardiovascular disease (CVD), and death
What is blood pressure and how is it determined?
- The force of circulating blood on the walls of the arteries. Blood pressure is taken using two measurements: systolic (measured when the heart beats when blood pressure is at its highest) and diastolic (measured between heartbeats, when blood pressure is at its lowest).
- Determined by the product of cardiac output and systemic vascular resistance
a. CARDIAC OUTPUT – the amount of blood ejected from the left ventricle and measured in Lpm
b. SYSTEMIC VASCULAR RESISTANCE – resistance to blood flow that is determined by the diameter of the blood vessels and vascular musculature
BP = CO X SVR
CO = Heart rate X Stroke Volume
The Goals of Anti-hypertensive therapy?
- Reduction of cardiovascular and renal morbidity and mortality
- The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7) – achieve a blood pressure of less than 140/90mmHg and for patients with hypertension and diabetes, less than 130/90mmHg
- Individualized considering comorbidities and impact on patient’s quality of life
Different types drugs for Anti-hypertensive drugs
- Diuretics
- Adrenergic Drugs
- Direct Vasodilators
- ACE Inhibitors
- Calcium Channel Blockers
- Direct Renin Inhibitors
- Angiotensin
- Receptor Blockers
Diuretics
Drugs that accelerate the rate of urine formation that results to the removal of sodium and water from the body
DIURETICS: CARBONIC ANHYDRASE INHIBITORS
- Chemical derivatives of sulfonamide antibiotics
- Drug : Acetazolamide
- Mechanism of action(MOA): Works along the carbonic anhydrase enzyme system in the proximal convoluted tubule Carbonic Anhydrase is needed to make hydrogen ions for the exchange of sodium and water.
- Once inhibited Na and H20 will not be reabsorbed thus excretion is accelerated
- Indications: treatment of Glaucoma, Edema, and High-altitude sickness
- contraindication(C/I): drug allergy, hyponatremia, hypokalemia, cirrhosis, and renal, liver, and adrenal gland dysfunction
*Adverse Effects(A/E): metabolic acidosis, hypokalemia, drowsiness, photosensitivity - Interactions: Digoxin toxicity
DIURETICS: LOOP
- Chemically related to the sulfonamide antibiotics
- Drugs : Bumetanide, Furosemide, Torsemide
- Mechanism of action(MOA): acts on the ascending LoH, blocks Cl and Na resorption, activate
prostaglandins leading to vasodilation - Indications: edema associated with heart, hepatic or renal failure, control hypertension, and increased renal excretion of calcium
- contraindication(C/I): drug allergy, hepatic coma, and severe electrolyte loss
- Adverse Effects(A/E): hypokalemia, blood disorders: decreased blood values
- Interactions: Aminoglycosides increase neuro and ototoxicity, Digoxin increase the risk for toxicity, Non-steroidal anti-inflammatory drugs (NSAIDs) decrease diuretic activity
DIURETICS: OSMOTIC
- Osmotic diuretics increase tubular fluid osmolarity, pulling water into the collecting tubules and preventing water reabsorption, which results in osmotic diuresis. The primary osmotic diuretic used clinically is mannitol. The primary indication for mannitol is to treat cases of increased intracranial or
intraocular pressure, which can have significant effects on fluid volume and sodium concentration, so caution must be exercised when using these agents.
Drug: Mannitol - Mechanism of action(MOA): a non-absorbable solute that
works on the entire nephron esp. LoH
and PCT. Increases osmotic pull in the
filtrate which produces a rapid diuresis - Drug of Choice(DOC) for preventing kidney damage during acute kidney injury and reduction of intracranial pressure and cerebral edema
- contraindication(C/I): drug allergy, severe renal disease, pulmonary edema, active intracranial bleeding
- Adverse Effects(A/E): Convulsions, thrombophlebitis, and pulmonary congestion
DIURETICS: POTASSIUMSPARING
- DRUGS: Spironolactone, Triamterene, Amiloride
- Mechanism of action(MOA): works on the collecting ducts and DCT by blocking the aldosterone receptor
- Indication: hyperaldosteronism, hypertension, reverse potassium loss caused by other diuretics, pediatric clients with heart failure
- contraindication(C/I): allergy and hyperkalemia
DIURETICS: THIAZIDES
- Chemical derivatives of sulfonamides
- Drugs: Chlorothiazide and Hydrochlorothiazide, Metolazone
- Mechanism of action(MOA): works in the DCT by inhibiting Na, K, and Cl resulting in osmotic water loss; can cause direct relaxation of arterioles which decreased afterload
+ Indications: Edema, Hypercalciuria, Diabetes insipidus, adjunct for heart and hepatic failure - contraindication(C/I): drug allergy, hepatic coma, anuria, and renal failure
- Adverse Effects(A/E): hypokalemia, increase Ca, Lipids, Glucose, and uric acid, headache, impotence and decreased libido
What are Adrenergic drugs and the different types?
Adrenergic drugs are a broad class of medications that bind to adrenergic receptors throughout the body. These receptors include:
alpha-1,
alpha-2,
beta-1,
beta-2,
beta-3.
Adrenergic drugs will bind directly to one or more of these receptors to induce various physiologic effects
- Central Acting – acts on the brain by decreasing NE production
+ Drugs: Clonidine, Methyldopa
- Peripheral Acting – at the heart and blood vessels
+ Drugs: Alpha and Beta Blockers
Nursing process for Diuretics
A. Assessment:
1. Obtain patient and medication history, and perform physical assessment (breath and heart sounds, skin turgor, V/S, weight, I&O)
2. Check laboratory findings (BUN, Creatinine, AST, ALT, Serum Electrolytes)
3. CAI, Loop and Thiazides may lower hypokalemia. Monitor pulse rhythm and ECG changes
4. PS may increase serum K: avoid bananas, oranges, apricots, raisins, broccoli, green beans, potatoes, tomatoes, fish, legumes
B. Diagnoses:
1. Decreased cardiac output related to drug effects and adverse effects of diuretics (e.g., fluid and electrolyte loss)
2. Deficient fluid volume related to drug effects and adverse effects of diuretics
3. Risk for injury related to postural hypotension and dizziness
C. Implementation:
1. Check pulse for 1 full minute
2. Increase fiber in the diet d/t constipation risks
3. Accurate dosing and timing to minimize adverse effects (usually morning dose to prevent nocturia)
4. Maintain adequate fluid intake.
5. Encourage to rise and change positions slowly
6. Monitor blood glucose regularly
Adrenergic Drugs
- Indications: Hypertension, Glaucoma
- Clonidine: used for the prevention of migraine headaches and severe dysmenorrhea, mgt of opioid, nicotine, and alcohol withdrawal
- Contraindication (C/I): drug allergy, acute heart failure, peptic ulcer
- Adverse Effects(A/E): postural hypotension, bradycardia, dry mouth, dizziness
- First Dose Syncope – severe hypotension resulting in loss of consciousness
- Abrupt discontinuation may lead to rebound hypertension
Antihypertensives drugs: Angiotensin-Converting Enzyme Inhibitors (ACEI)
- Drugs: Captopril, Enalapril, Lisinopril, Quinapril
- Mechanism of action(MOA): prevent an enzyme in the body from producing angiotensin II, a substance that narrows blood vessels. This narrowing can cause high blood pressure and forces the heart to work harder. Angiotensin II also releases hormones that raise blood pressure.
- Indications: Hypertension, adjunct for
heart failure, stop the progression of LVH - Contraindication (C/I): drug allergy, hyperkalemia, lactating women, children, and bilateral renal artery stenosis
- Adverse Effects(A/E): fatigue, dizziness, headaches, dry, non-productive cough, first dose effect
- Interactions: NSAIDs reduce the effect and potassium supplements
Antihypertensives drugs: Angiotensin II Receptor Blockers
- Drugs: Losartan, Eprosartan, Valsartan,
Irbisartan, Olmesartan, Telmisartan - Mechanism of action(MOA): block binding of Angiotensin II to its receptors and primarily affects
the vascular smooth muscle and adrenal gland - Indication: hypertension and adjunct for heart failure
- Contraindication (C/I): drug allergy, pregnancy, and lactation
- Adverse Effects(A/E): URTI, dizziness, insomnia, fatigue, diarrhea, back pain
Antihypertensives drugs: CALCIUM CHANNEL BLOCKER
- 3 types of Calcium Channel Blocker drugs
a. Phenylalkylamines - Verapamil
b. Benzothiazepines - Diltiazem
c. Dihydropyridines – Amlodipine, Nicardipine, Nifedipine - Mechanism of action(MOA): blocks calcium from the excitation-contraction coupling process in heart and vascular smooth muscle cells resulting in vasodilation; decreases afterload, depression of conduction through SA and AV nodes
- Indications: first-line drugs for angina, hypertension, supraventricular tachycardias; coronary spasms, short-term mgt of atrial fibrillation and flutter, migraine, Raynaud’s disease
- Drug: Nimodipine drug of choice for patients having cerebral artery spasms due to aneurysm rupture
- Contraindication (C/I): drug allergy, acute MI, second/third degree AV block, hypotension
- Adverse Effects(A/E): hypotension, palpitations, constipation, nausea, peripheral edema
What are supraventricular tachycardias, atrial fibrillation, and flutter?
- supraventricular tachycardia (SVT) (HR: 150-250 bpm)
- This arrhythmia has such a fast rate that the P waves may not be seen - Atrial Fibrillation (HR: 250-350 bpm)
- The AV node conducts impulses to the ventricles at a 2:1, 3:1, 4:1, or greater ratio (rarely 1:1).
- The degree of AV block may be consistent or variable. - Atrial Flutter (HR: more than or equal to 350 bpm)
- Rapid, erratic electrical discharge comes from multiple atrial ectopic foci (Ectopic foci are abnormal pacemaker sites within the heart (outside of the SA node) that display automaticity).
- No organized atrial depolarization is detectable.
Vasodilators Drugs
- Drugs: Minoxidil, Hydralazine, Diazoxide, Nitroprusside
- Mechanism of action(MOA): directly cause peripheral vasodilation
- Minoxidil (Drug) – effective in restoring hair growth
- Nitroprusside (Drug) - both arterial and venous vasodilation
- Indications: hypertension
- IV Nitroprusside and Diazoxide – hypertensive emergencies
- Contraindication (C/I): drug allergy, hypotension, cerebral edema, head injury, acute MI
- Adverse Effects(A/E): hypotension, dizziness, headache, orthostatic hypotension, dysrhythmias, sodium and water retention, hyperglycemia
Nursing process for Vasodilators
A. Assessment:
- Obtain health history, physical assessment, and V/S
- Monitor labs: Na, K, Cl, Mg, Ca, Troponin, BUN and Creatinine, ALT, AST
- Adrenergic drugs – watch out for edema, BP and HR, first-dose syncope (2-6hrs)
- Angiotensin-Converting Enzyme Inhibitors (ACEI) – assess BP, Apical pulse, respiratory status (dry cough), and CBC
- Angiotensin II Receptor Blockers (ARBs) – assess the renal function of elderly clients
- Vasodilators – assess neurological status, use with extreme caution to elderly
B. Diagnoses:
1. Ineffective peripheral tissue perfusion related to the impact of the hypertensive disease process and/or possible severe hypotensive adverse effects associated with antihypertensive drug therapy
2. Sexual dysfunction related to adverse effects of some antihypertensive drugs
3. Constipation related to the adverse effects of antihypertensive drugs
4. Noncompliance with drug therapy related to lack of familiarity with or acceptance of the disease process
5. Risk for injury (e.g., possible falls) related to possible antihypertensive
drug–induced orthostatic hypotension with dizziness and syncope
C. Implementation:
1. Monitor for adherence to medication regimen
2. Advise patients to monitor BP and HR at home
3. For Adrenergic antagonists d/t to first dose syncope – patient should remain supine for the first dose and given at nighttime
4. Some patients using bet—blockers may experience an exacerbation of respiratory diseases such as asthma, bronchospasm, and heart failure
5. Provide clear, concise instructions about reporting Adverse effects
6. Drugs may induce rebound hypertension, so advice against abrupt discontinuation.
7. Hydralazine may trigger SLE (systemic lupus erythematosus) (>200mg/day PO), discontinue the drug, and notify the physician immediately. (S/Sx: photosensitivity, rashes, CNS changes, and blood dyscrasias)
8. Cyanide toxicity may be induced by nitroprusside administration. Dilute the medication properly and avoid the solution turning blue, green, or red. Use infusion pump and continuous monitoring of BP
Health teaching for patients having hypertensive medications
- Medications are taken exactly as prescribed
- Hypertension management includes dietary restrictions (low-salt, low fat), monitoring stress levels and exercise, and avoidance of smoking and alcohol.
- Emphasize recording of blood pressure readings and daily weights
Anginal symptoms: Heart and Chest pains
- Very efficient organ that pumps blood to all tissues and organs
- Requires large supply of oxygen from the coronary arteries to meet demands
- Poor blood supply (decreased O2 and nutrients) leads to angina pectoris (chest pain) and ischemia
- The pain felt is due to anaerobic metabolism that increases production of lactic acid which stimulates pain receptors
