Cardiac Medications Flashcards
It is recommended that these agents be administered within 4 to 6 hours after the onset of pain if cardiac catheterization is not possible in 90 minutes, since permanent myocardial necrosis may occur if coronary perfusion has not been restored within that time. If these drugs are given prior to transfer to SBH the patient will remain in ACCU or ICMS for 24 hours before being transferred to 5A cardiology.
These drugs are also referred to as fibrinolytic agents. Thrombolytic therapy is indicated for lysis of intracoronary thrombi in the early stages of an acute MI. Tenecteplase (TNKase), tissue plasminogen activator (tPA), urokinase and streptokinase are common thrombolytic agents.
These drugs are used in MI patients to decrease the possibility of extension of coronary thrombi, to prevent development of left ventricular (LV) clot, and to decrease the likelihood of venous thromboembolism.
Anticoagulants - Heparin / Warfarin
- prevents coagulation by inhibiting the conversion of prothrombin to thrombin, preventing thrombin from acting as a catalyst in converting fibrinogen into fibrin, and preventing aggregation of platelets.
- increases the clotting time of blood by disrupting the clotting process in proportion to the availability of the patient’s clotting factors and the dose of the drug administered.
Heparin
inhibits the synthesis of vitamin K-dependent factors II, VII, IX and X along with regulatory proteins C, S and Z. This interruption in the clotting cascade leads to an increase in INR which is followed to determine warfarin dosing.
Warfarin
commonly added to treatment of heart failure for African Americans who remain symptomatic while on ACEi + BB+ MRA. These are shown to reduce morbidity and mortality for all patients who cannot tolerate ACEi, ARB, or ARNI.
Vasodilators - hydralazine, isosorbide dinitrate
newer medication that lowers heart rate with no effect on contractility. It is an inhibitor of the If current in the SA node, which is the channel that initiates impulses. As it does not modify myocardial contractility or conduction, it has no effect on BP. This medication can be added on to ACEi/ ARB + BB + MRA if the patient is in normal sinus rhythm with a resting heart rate of greater than77bpm.
Ivabradine
What are common MRAs
Spironolactone and eplerenone
Antagonism of aldosterone receptors inhibits sodium reabsorption in the kidney. This interferes with Na/K+ exchange and reduces urinary K+ excretion and weakly increases diuresis. These are added for on after ACEi and BB. Monitor Cr & K+. Patients should not take K+ supplementation after initiation, and should avoid high K+ foods and NSAIDs. Check Cr and K+ 2-3 days and 7 days after initiation
MRAs (Spironolactone, Eplerenone)
- These drugs have been shown to reduce morbidity and mortality following an MI with reduced ejection fraction (EF), heart failure or anterior MI. All patients with an EF of less than 40%, patients with hypertension, diabetes mellitus or stable chronic kidney disease should be on an it.
- block the conversion of angiotensin I to angiotensin II, thereby causing vasodilation.
- These agents are commonly used to improve left ventricular function and reduce the progression of CHF. They are also first-line therapy in the treatment of hypertension.
Angiotensin converting enzyme inhibitors (ACEi)
an oral nitrate which does not relieve pain of an angina
attack like nitroglycerine does but over time it works to dilate coronary vessels to improve flow and oxygen delivery and reduce myocardial oxygen demand.
Isordil
- are among the oldest cardiac medications and are effective for patients with angina.
- dilate large arteries and veins (capacitance vessels). In patients with angina, relief is achieved primarily as a result of venous dilation. Venodilation reduces cardiac preload, which in turn reduces ventricular filling pressures and volumes, decreases ventricular wall stress, and ultimately reduces oxygen demand of the myocardium.
Nitrates (Nitroglycerin, Isordil)
prevent the influx of calcium ions through specialized cell membrane channels of the myocardium and vascular smooth muscle. By blocking calcium influx,
- relax arterialsmooth muscle and cardiac muscle. Coronary vessels dilate, increasing myocardial perfusion and collateral flow. The oxygen demand on the heart decreases while the oxygen supply increases.
These agents decrease heart rate by slowing conduction in the SA and AV nodes and also reduce
myocardial contractility.
Calcium channel blockers (verapamil, amlodipine, dilitazem, nifedipine)
Therapeutic class: Antiarrhythmic; anticholinergic
Indication: excessive secretions, sinus bradycardia, heart block
Action: Inhibition of acetylcholine, increasing the HR, causing bronchodilation, and decreasing secretions.
Nursing Considerations:
● Monitor for urinary retention and constipation
● Avoid in clients with glaucoma
Atropine
Anticholinergic and antiarrythmic that is used for bradycardia
Atropine
Indication: Used for many dysrhythmias.
Action: Blocks sodium channels, which slows impulse conduction and delays repolarization.
Nursing Considerations:
● Adverse effects:
○ Diarrhea ○ SLE-like syndrome ○ Negative inotropic effects → hypotension, cardiosupression
SODIUM CHANNEL BLOCKERS (Procainamide, Lidocaine)
