Heart+Failure+Drugs

=WHAT IS HEART FAILURE? A pathological state in which the heart is unable to pump blood in sufficient amounts from the ventricles to meet the body's metabolic needs. It can affect the left ventricle, right ventricle, or both simultaneously. Reduction of ejection fraction to left ventricle end-diastolic volume = Heart Failure! = ( =

What happens?  Heart cannot meet the the increased demands placed on it and the blood supply to certain organs is reduced. Organs with the most blood supply dependency are the last one to be deprived ( brain and heart).

Left sided heart failure?  Often leads to pulmonary edema, coughing, shortness of breath, and dyspnea

Right sides heart failure?  Typically involves systemic venous congestion, pedal edema, jugular venous distention, ascites, hepatic congestion

What data needs to be assess?  BP, plulse rate (apical and radial), capillary refill, heart sounds, weight, I&O, electrocardiogram, serum laboratory results, liver function laboratory results, medication history (full history), dietary habits, smoking history, alcohol consumption/history

Nursing diagnoses...  Ineffective cardiopulmonary tissue perfusion r/t pathophysiologic influence of heart failure.  Deficient knowledge r/t first time heart failure.  Imbalanced nutrition, less than body requirements, r/t side effects of medication.

Goals...  Patient exhibits improved cardiac output once therapy is initiated <span style="font-family: Georgia,serif; font-size: 140%;"> Patient states uses, action, adverse effects, toxic effects of therapy <span style="font-family: Georgia,serif; font-size: 140%;"> Patients appetite is improved

<span style="font-family: Georgia,serif; font-size: 140%;">Outcomes... <span style="font-family: Georgia,serif; font-size: 140%;"> Patient has strong peripheral pulses, increased endurance for activity,decreased fatigue, pink and warm extremities <span style="font-family: Georgia,serif; font-size: 140%;"> Patient has increased urinary output <span style="font-family: Georgia,serif; font-size: 140%;"> Patient has improved heart and lungs sounds with decreased dysrhythmias and crackles

Pharmacological treatment: Drug Classes and Mechanism of action of key Heart failure drugs What are Inotropic,Chronotropic, and Dromotropic drugs? - Each has a positive and negative effect. Positive effects of each: + Inotropic drugs increase the force of myocardial contraction. + Chronotropic drugs increase the rate at which the heart beats. + Dromotropic drugs accelerate the conduction of the heart. All negative drugs do the opposite. Heart failure is treated with two inotropic drugs ( Phosphodiesterase inhibitors and cardiac glycosides), but they are recommended after the patient starts therapy with : angiotensin-converting enzyme (ACE) inhibitors, Angiotensin receptor blockers, beta blockers, and diuretics as well. Note: Digoxin used to be the mainstay in heart failure treatment, but it has been replaced by other drugs due to drug interactions, adverse effects, and a low therapeutic dosage range. The goal in the heart failure treatment is to reduce the effects of the renin-angiotensin-aldosterone system and the sympathetic nervous system. As noted DIGOXIN is added to the treatment only after ACE inhibitors, angiotensin receptors, beta blockers, and diuretics are used. Angiotensin-Converting Enzyme Inhibitors Quick fact: Ace inhibitors were discovered from a substance found in the venom of a South American Viper. <span style="background: none repeat scroll 0% 0% yellow; font-family: Calibri; font-size: 16pt; line-height: 115%; margin: 0in 0in 10pt;">How they work: They inhibit ACE, an enzyme that converts angiotensin I to angiotensin II. It is important because angiotensin II is a vasoconstrictor which increases systemic vascular resistance (SVR) and BP goes up, and it induces aldosterone secretion by the adrenal glands. Aldosterone stimulates sodium and H2O resorption, which raises BP. These drugs help reduce the heart afterload by inhibiting sodium and H2O resorption by inhibiting aldosterone secretions, and prevent vasoconstriction by inhibiting the conversion of angiotensin II. Indications: They are used to treat Heart failure as well as hypertension. They are able to reduce Systemic vascular resistance, which allows the heart to reduce its blood pressure. They are able to reduce glomerular filtration pressure which protects the kidney from renal failure. <span style="background: none repeat scroll 0% 0% red; font-family: Calibri; font-size: 16pt; line-height: 115%; margin: 0in 0in 10pt;">Contraindications and side effects: These drugs are contraindicated in patient who developed an allergic reaction with angiodema to other ACE inhibitors. It is contraindicated for patients with potassium leves of >5mEq/L because they promote hyperkalemia. Some of the common side effects are fatigue dizziness, mood changes, headaches and a dry non-productive cough. Drug interactions: NSAIDS reduce the effect of the ACE inhibitors and they may predispose patients to the development of acute renal failure. Lithium can be toxic if used with ACE inhibitors. Angiotensin II Receptor Blockers <span style="background: none repeat scroll 0% 0% yellow; font-family: Calibri; font-size: 16pt; line-height: 115%; margin: 0in 0in 10pt;">How they work: ARB’s block the binding of AII to type 1 AII receptors. They are similar to ACE inhibitors, but they affect primarily vascular smooth muscle and the adrenal gland. ARBs block vasoconstriction and the secretion of aldosterone. Another difference is that they do not cause cough. Basically they promote peripheral vasodilatation. Indications: They are used to treat hypertension and heart failure. Contraindications and side effects: They are contraindicated to use in the 2nd or 3rd trimester of pregnancy. Some of the side effects include dizziness, inability to sleep, diarrhea, dyspnea, heartburn and nasal congestion among others. Drug Interactions: Lithium may have increase concentrations and a longer period of elimination when used with ARBs. Rifampin decreases the ARB effect. Beta Blockers <span style="background: none repeat scroll 0% 0% yellow; font-family: Calibri; font-size: 16pt; line-height: 115%; margin: 0in 0in 10pt;">How they work: Beta-blockers work by reducing or blocking sympathetic nervous system stimulation to the heart and the heart’s conduction system. The result of blocking the stimulation include reduced heart rate, delayed AV node conduction, reduced myocardial contractility and decreased myocardial automaticity. Indications: used to treat hypertension and angina. Diuretics: How they work: They inhibit sodium and chloride resorption. They increase dieresis and reduce excessive blood volume. Indications: Heart Failure, Hepatic or Renal disease, and hypertension. Contraindications and side effects: side effects include electrolyte imbalance, dizziness, blurred vision, tinnitus and headache. Phosphodiesterase Inhibitors How they work: They are inotropic drugs that inhibit the action of the enzyme phosphodiesterase. Drugs approved: Inamrinone and milrinone. The beneficial effects of milrinone and inamrinone come from the intracellular increase in cyclic adenosine monophosphate (cAMP). The result is a positive inotropic response and vasodilation. These drugs have strong affinity for smooth muscle fibers in the lungs and the systemic blood vessels which increases blood flow and reduces the workload of the heart. Inhibition of phosphodiesterase also results in more calcium available for the heart to contract more forcefully. Indications: They are used in the intensive care unit setting for short term heart failure. These drugs may be used on weekly infusions for long-term patients. The purpose is to decrease hospitalizations for heart failure episodes. Contraindications and side effects: Include past drug allergy and severe aortic or pulmonary valvular disease. Adverse effects of Inamrinone: Thrombocytopenia (Usually with high doses), dysrhthmia, nausea, hypotension and elevations in liver enzyme levels with prolonged use. Adverse effects of Milrinone: Dysrhythmia (mainly ventricular), hypotension, angina, hypokalemia, tremor, and thrombocytopenia. Toxicity: Hypotension secondary to vasodilation is common with excessive dosages. There is no antidote and we need to discontinue the drug if excessive hypotension occurs. IV initiation may be required to support the circulatory system. Interactions: Concurrent administration of diuretics may cause hypovolemia and add the hypotensive effects. Furosemide must not be injected into IV lines because it will crystallize. Dosages: Milrinone and inamrinone are pregnancy category C.  ** Drug ** **Drug class** **Dosage Range** **Indication** Milrinone Phosphodiesterase inhibitor **ADULT:** Heart Failure (Primacor) **IV loading dose: 50mcg/kg** ** Continuous infusion: 0.375-0.75mcg/kg ** Cardiac Glycosides The only approved drug in U.S. is Digoxin. How it works: Digoxin produces a positive inotropic effect which increases the force of myocardial contraction (it inhibits the sodium-potassium ATP pump, increasing calcium availability). It has a negative chronotropic effect which decreases the heart rate. How? It decreases the rate of electrical conduction and gives more time to the ventricles to fill with blood coming from the atria, resulting in an increased cardiac output. Indications: Digoxin is used to treat systolic heart failure and atrial fibrillation. (It is recommended to use with ACE inhibitors, ARB’s, diuretics and beta blockers). It improves nocturnal dyspnea, cough and cyanosis related to oxygen deprivation because of improved blood flow. Digoxin improves coronary circulation, reduces heart size during diastole, decreases blood pressure and vein engorgement, improves quality of life but there is no evidence of reduced mortality rates. Contraindication and side effects: Major adverse effects: Dysrhythmias ( caused by disrupting electrical conduction), including tachycardia or bradycardia, and hypotension. It may cause fatigue, headache, confusion, anorexia, NVD, and colored vision. Digoxin is a pregnancy risk category C.  Toxicity: Digoxin has a low therapeutic window. Therefore patients need to be monitor since the beginning of drug therapy. NORMAL THERAPEUTIC LEVELS are: 0.5 to 2ng/mL. Toxicity is as high as 20% in patients taking digoxin. Low potassium level increases the risk for toxicity. Potassium levels should be between 3.5 to 5.0 mEq/L. Digoxin is excreted primarily by the kidney so we need to verify for renal failure before giving digoxin. If overdose occur digoxin immune Fab is usually indicated. (An antibody that recognizes the drug as an antigen, and it inactivates the free digoxin. In life threating overdose >10mg in adults and >4mg in children.   Interactions: Digoxin is interactive with other medications such as antidysrhytmics and calcium because they increase digoxin toxicity. Loop diuretics (Furosemide may lead to hypokalemia) increasing the risk for dysrhythmias. Potassium supplements may decrease the effects of digoxin. Verapamil increases plasma level of digoxin by 50%, and therefore digoxin dose should be reduced 50%. Barbituates increase therapeutic effect. Quinidine and calcium channel blockers enhance bradycardic effect.  <span style="background: none repeat scroll 0% 0% lime; font-family: Calibri; font-size: 16pt; line-height: 115%; margin: 0in 0in 10pt;">Dosages:  ** Digoxin Drug Class: ** Digitalis Cardiac Glycoside   ** Indication ** Heart Failure and SV dysrhythmias ** Dosage Range: ** <span style="background: none repeat scroll 0% 0% red; font-family: Calibri; font-size: 16pt; line-height: 115%; margin: 0in 0in 10pt;">Pediatric depends on age: IV: 0.008-0.0035mg/kg premature infant to >10 Yrs PO: 0.010-0.060mg/kg Premature infant to >10 Yrs <span style="background: none repeat scroll 0% 0% red; font-family: Calibri; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">ADULT: IV/PO digitalizing dose: 1-1.5 mg/day Maintenance dose: 0.125mg/day Nursing Implications <span style="color: #333333; font-family: 'Tahoma','sans-serif'; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">- Before use Assess history of allergies, BP, apical pulse for 1 full minute, serum lab values for potassium, sodium, calcium, renal and liver function. <span style="color: #333333; font-family: 'Tahoma','sans-serif'; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">-Monitor serum levels of Potassium to maintain a level between 3.5 to 5.0 mEq/L. <span style="color: #333333; font-family: 'Tahoma','sans-serif'; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">-Instruct Clients of possible GI side effects which include N/V/D and abdominal pain and to report them to the physician. <span style="color: #333333; font-family: 'Tahoma','sans-serif'; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">-Assess client for vision changes such as color vision or white halos around objects. <span style="color: #333333; font-family: 'Tahoma','sans-serif'; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">- Monitor digoxin levels periodically during treatment and maintain therapeutic levels of 0.5 to 2.0 ng/mL to prevent toxicity. <span style="color: #333333; font-family: 'Tahoma','sans-serif'; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">-Check pulse rate before administration of digoxin. Notify physician if heart rate is <60 beats/ Min. <span style="color: #333333; font-family: 'Tahoma','sans-serif'; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">-If verapamil is concurrently with digoxin, reduce digoxin dose by 50% or notify health care provider. <span style="color: #333333; font-family: 'Tahoma','sans-serif'; font-size: 16pt; line-height: normal; margin: 0in 0in 10pt;">-Monitor for weight gain of 2lb per day or 5lb in a week.

<span style="background: none repeat scroll 0% 0% red; color: #000000; display: block; font-family: Calibri; font-size: 48pt; line-height: 115%; margin: 0in 0in 10pt; text-align: center;">Quiz <span style="color: #000000; font-family: Calibri; font-size: 22pt; line-height: 115%; margin: 0in 0in 10pt;">1. What is the normal therapeutic level for digoxin? <span style="color: #000000; font-family: Calibri; font-size: 22pt; line-height: 115%; margin: 0in 0in 10pt;">2. What are some of the common adverse effects of Digoxin? <span style="color: #000000; font-family: Calibri; font-size: 22pt; line-height: 115%; margin: 0in 0in 10pt;">3. Name two nursing implications associated with the use of Digoxin? <span style="color: #000000; font-family: Calibri; font-size: 22pt; line-height: 115%; margin: 0in 0in 10pt;">4. What is a positive inotropic effect? <span style="color: #000000; font-family: Calibri; font-size: 22pt; line-height: 115%; margin: 0in 0in 10pt;">5. Name some drug interactions related with digoxin. <span style="color: #000000; font-family: Calibri; font-size: 22pt; line-height: 115%; margin: 0in 0in 10pt;">Answers: <span style="color: #000000; font-family: Calibri; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt;">1. 0.5 to 2 ng/mL <span style="color: #000000; font-family: Calibri; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt;">2. Mainly Dysrhythmias, color and halo vision, hypotension, and anorexia among others. <span style="color: #000000; font-family: Calibri; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt;">3. Assess for vital signs and serum levels of potassium and electrolytes. Monitor for side effects and report any adverse effect to the primary healthcare provider. <span style="color: #000000; font-family: Calibri; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt;">4. A positive inotropic drug increases myocardial contractility. <span style="color: #000000; font-family: Calibri; font-size: 12pt; line-height: 115%; margin: 0in 0in 10pt;">5. Antidysrhythmics which increase digoxin toxicity, verapamil which increases digoxin levels by 50% and potassium supplements which decrease effectiveness of digoxin.