Unit 23 Medications Used for Cardiovascular System Disorders
Terms in this set (39)
Digitalis is obtained by crushing the dried leaves of the plant Digitalis purpurea or purple foxglove into a powder.
A similar drug, digoxin, is obtained from the leaves of Digitalis Ianatas.
The primary use for these and other digitalis compounds is the treatment of various types of heart failure and together they belong to a chemical classification known as cardiac glycosides.
These drugs exert a positive inotropic efect on the heart.
They strengthen the heart muscle (myocardium), increase the force of systolic contraction, slow the heart and improve the muscle tone of the myocardium.
Action - Digitalis drugs strengthen the heart muscle, increase the force and velocity of myocardial systolic contraction - positive inotropic effect, slow the heart rate - negative chronotropic effect, and decrease conduction velocity through the artioventricular (AV) node.
Uses - Congestive heart failure, atrial fibrillation, atrial flutter, paroxysmal atrial tachycardia
Caution: Anorexia,nausea, vomiting, and arrhythmias may be indications of digitalis intoxication.
Implications for Patient Care - Assess the apical pulse for one minute before administering digitalis drugs.
Withhold the medication if the pulse is below 60 or the minimum specified by the prescribing physician.
Monitor intake and output ratio, daily weight, liver function studies, serum electrolytes, creatinine, and drug levels.
Be alert for signs of digitalis toxicity and hypokalemia. Evaluate the therapeutic response of medication.
Signs and symptoms of Digitalis Toxicity
The most common early symptoms of digitalis toxicity are anorexia, nausea, vomiting,and arrhythmias.
• Gastrointestinal: anorexia, nausea, vomiting , diarrhea, abdominal pain.
• Nervous system: headache, restlessness,irritability, drowsiness, depression, confusion, disorientation, insomnia, psychosis, convulsions, coma, blurred or yellow vision.
• Cardovascular: bradycardia, tachycardia, atrial tachycardia with varying AV block, ventricuar bigeminy, ventricular tachcardia, second degree AV block, complete AV block
• musculoskeletal: severe weakness
Disorders of the SA node that interfere with impulse formation or disorders with the conduction system - AV node, Bundle of His - result in a variety of cardiac arrhythmias.
The term arrhythmia means irregularity or loss of rhythm, and is commonly used to describe an irregular heartbeat.
Some cardiac arrhythmias do not require treatment, whereas other may result in death inf not treated by drug therapy or the use of an artificial pacemaker.
Vasopressors and Vasodilators
Vasopressers are drugs that cause contraction of the muscles associated with capillaries and arteries, thereby narrowing the space through which the blood circulates.
This narrowing increases the resistance to blood flow and results in an elevation of blood pressure.
Drugs classified as vasopressors are useful in treatments of patients suffering from shock.
Vasodilators are medications that cause the relaxation of blood vessels.
This action dilates the vessels thereby increasing their ability to carry blood.
This eases resistance to blood flow and lowers blood pressure.
Vasodilators may be classified as coronary or peripheral vasodilators.
lidocaine HCl - Xylocaine HCl
quinidine sulfate - Extentabs
Oral: 200 to 300 mg 3 to 4 times daily
phenylephrine HCl - Neo-Synephrine 1 % Injections
Peripheral Vasodilators Drugs - papaverine HCl
Antihypertensive Agents Drugs
Loop diuretics - furosemide - Lasix
20 to 80 mg/day
Beta-blockers - atenolol - Tenormin, metoprolol - Lopressor
ACE inhibitors - lisinopril - Prinivil, Zestril, quinapril - Accupril
calcium channel blockers non-dihydropyridines - diltiazem extended release - Cardizem CD, Dilacor XR, Tiazac
Alpha 1-blockrs - prazosin - Minipress
Drugs that Affect the Blood
Anticoagulants are used therapeutically after a thrombus or blood clot has formed.
They do not alter the size of an existing thrombus; however they do act to prevent further growth and reduce the possibility of embolization.
Caution: Heparin is not intended for intramuscular use. Hemorrhage can occur at almost any site in patients receiving heparin.
Warfarin Sodium - Coumadin Caution
1. hemorrhage can occur at almost any site in patients on anticoagulant therapy.
2. Anticoagulant therapy with Coumadin may enhance the release of atheromatous plaque emboli.
3. Use caution during lactation, severe to moderate hepatic or renal insufficency, trauma that may result in internal bleeding, surgery or rauma resulting in large exposed raw surfaces,
and in patients with indwelling catheers, severe to moderate hypertension, known or suspected deficiency in protein C, polycythemia vera, vasculitis, severe diabetes and severe allergic and anaphylacic disorders.
4. A patient receiving Coumadin must have periodic and carefully monitored prothrombin time or other suitable coagulation test.
For Coumadin patient teaching:
to avoid alcohol, salicylates -asprin, large amounts of green vegetables - high in vitamin K - or drastic changes in dietary habits, which may affect coumadin therapy.
That coumadin can cause a red orange discoloration of alkaline urine. Watch for bleeding.
Thrombolytic agents act to dissolve an existing thrombus when administered soon after is occurrence.
These agents dissolve the clot, reopen the artery, restore blood flow to the heart, and prevent further damage to the myocardium.
Hemostatic agents may be administered systemically to over come specific coagulation defects, or applied topically to control surface bleeding. Certain of these drugs are used in the treatment of hemophilia - ProPlex - an for hypofibrinogenemia - Amicar, vitamin K.
Other products known as locally absorbable hemostatics, are applied topically to control capillary oozing and surface bleeding.
Examples of these are gelatin sponge - Gelfoam, oxidized cellulose - Surgicel - microfibrillar collagen - Avitene - and thrombin.
Epoetin Alfa - Epogen
Epogen is anerythropoiesis stimulating agent (ESA) that stimulates red blood cell production (erthropoeisis) ESA's structurally and biologically are similar to naturally occurring protein erythropoietin.
Its used for anemia associated with chronic renal failure or in AIDS patients.
Cholesterol Values and Associated Risk Level
Total Cholesterol: <200 mg/dL
LDL: <100 mg/dL
Total Cholesterol: 200-239 mg/dL
LDL: 130-159 mg/dL
Total Cholesterol: 240 mg/dL
LDL: 160-189 mg/dL
Total Cholesterol: >241 mg/dL
LDL: >190 mg/dL
Antihyperlipidermic Agents Dugs
atorvastatin calcium - Lipitor
Dose: 10 mg orally once daily
gemfibrozil - Lopid
lovastin - Mevacor
pravastatin - Pravachol
simvastatin - Zocor