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
