Cardiac Medications Flashcards
Background of angina pectoris
- Chest pain due to ischemic heart disease: caused by O2 demand/supply mismatch & can be predicted/exacerbated by physical exertion
- Very high prevalence in US: many patients receiving PT may suffer from this disease state
- Can be sudden & described as intense compression & tightness of the chest that can sometimes radiate to the jaw or left arm
Describe EKG anomalies
- Gives info about electrical activity in the heart
- Well established template where anomalies can be detected & help to determine what is happening to the heart muscle
Describe the parts of the EKG heart beat wave
- QRS: ventricle depolarization/contraction
- T: ventricle repolarization/relaxation
- ST segment: interval b/w depolarization & repolarization (elevation or depression or T wave inversion is often due to ischemia
Pharmacologic treatments for angina pectoris
- Nitrates
- Bete blockers
- Calcium channel blockers
Describe organic nitrates
- Prodrugs that are converted to nitric oxide (NO) within vascular smooth muscle
- Nitric oxide increases cGMP which inhibits smooth muscle contraction
- Produces general vasodilation -> decreases preload & afterload
- Reduces workload on the heart (decreased oxygen demand)
List organic nitrate drugs
- Nitroglycerin
- Isosorbide dinitrate
- Isosorbide mononitrate
Describe nitroglycerin (Nitrobid, Nitrostat)
- Used for acute Tx of anginal attacks
- Sublingual administration is preferred in acute attacks due to rapid absorption (therapeutic effects begin within 2 min; bypasses 1st pass effect)
- Can also be administered ar an aerosol, ointment, patch, or oral tablet (patch must be removed for 10-12 hrs due to development of tolerance)
- Used as a powerful explosive: this feature is inactivated by diluting with lactose, alcohol, or propylene glycol
Describe isosorbide dinitrate
- Used for Tx of acute episodes of angina & for prevention of future attacks
- Longer effects
- Sublingual, buccal, chewable, or oral tablets
- Primarily used as preventive medication
Describe isosorbide mononitrate
- Primarily used as preventive medication
- Similar to Isosorbide dinitrate but longer acting
Adverse effects of organic nitrate drugs
- Headache
- Dizziness
- Orthostatic hypotension
Describe beta blockers
- Drugs: Metoprolol, Labetalol, Carvedilol
- MOA: antagonist to beta1 receptors on the myocardium; decrease HR & myocardial contraction force; decreases O2 demands
- Adverse effects: nonselective agents may cause bronchoconstriction in pts with asthma; otherwise well tolerated; watch for excessive cardiac depression
Describe calcium channel blockers
- Drugs: Diltiazem, Verapamil, Amlodiopine, Nifedipine
- MOA: affects vascular smooth muscle cells causing vasodilation (systemic vasodilation causes decreased myocardial O2 demand); mediates coronary vasodilation (increases O2 supply)
- Adverse effects: peripheral vasodilation (headache, flushing, dizziness); peripheral edema; reflex tachycardia (-ipine)
Describe stable angina
- Myocardial O2 demand > supply
- Typically brought on by physical exertion
- Acute Tx: sublingual nitroglycerin
- Prevention: beta blockers or long acting nitrate
- Chest pain/discomfort can occur with physical exertion
Describe variant angina
- Coronary vasospasm causes a decrease in myocardial O2 supply
- Tx: calcium channel blocker
Describe unstable angina
- Myocardial O2 supply decreases at the same time O2 demand increases
- Due to atherosclerotic plaque rupture within coronary arteries
- Chest pain/discomfort can occur during physical exertion or rest
- Tx: requires further evaluation & a combination of pharmacologic & interventional therapies
Non-pharmacologic management of angina pectoris
- Pharmacologic agents only treat the symptoms not the condition
- Lifestyle changes: exercise, weight loss, smoking cessation, stress management
- Angina related to plaque build up or thrombosis can be addressed with cardiac catheterizations & subsequent intervention or coronary artery bypass surgery of needed
What type of patients require special sternal precautions to be aware of during PT
- CABG patients have a scar down their chest & require special sternal precautions
Key points for PT related to angina pectoris
- Ensure patient has PRN nitroglycerin if needed
- Beta blockers & calcium channel blockers may blunt the myocardial response to exercise
- All of these drugs can cause hypotension: may be exaggerated upon sudden sitting to standing
Background of arrhythmias
- Arrhythmia: any significant deviation from normal cardiac rhythm
- Untreated arrhythmias can result in impaired cardiac function & may be associated with CVA, heart failure, & fatalities
Normal cardiac rhythm/electrical conduction pathway
- Sinoatrial node (SA)
- Atrioventricular node (AV)
- Bundle of His
- Left/Right bundle branches
- Purkinje Fibers
Classification of Antiarrhythmic drugs
- Class I: Sodium channel blockers
- Class II: Beta blockers
- Class III (drugs that prolong repolarization): K+ channel blockers
- Class IV: Calcium channel blockers
- Others: Digoxin
List class I sodium channel blockers
- Class IA: Quinidine, Procainamide
- Class IB: Lidocaine, Mexilatine
- Class IC: Flecainide, Propafenone
MOA and adverse reactions of class I sodium channel blockers
- MOA: control the rate of Na entry; control excitation/conduction to stabilize the cardiac cell membrane
- Adverse effects: increased arrhythmias, dizziness, visual disturbance, N/V, diarrhea
List class II beta blocker drugs
- Atenolol
- Esmolol
- Metoprolol
MOA and adverse effects of class II beta blockers
- MOA: decrease excitatory effects of the sympathetic NS; slows conduction through the myocardium (blocks AV node)
- Adverse effects: Non-selective = increased bronchoconstrictionn; bradycardia, orthostatic hypotension
List class III K+ channel blockers
- Amiodarone
- Dofetilide
- Dronedarone
MOA and adverse effects of class III K+ channel blockers
- MOA: prolong the effective refractory period; slows & stabilizes the HR
- Adverse effects: torsades de pointes (pro-arrhythmic); amiodarone = pulmonary, thyroid, liver toxicity
List class IV calcium channel blockers
- Verapamil
- Diltiazem
MOA and adverse effects of CLass IV calcium channel blockers
- MOA: block calcium influx which alters the excitability & conduction; decrease the rate of discharge of the SA node & inhibit velocity through the AV node
- Adverse effects: excessive bradycardia, peripheral vasodilation = dizziness & headache
Non-pharmacologic treatment of arrhythmias
- Drugs do not resolve cause of arrhythmia
- Implantable devices: pacemakers, defibrillators
- Interventions: ablations
Key points for PT for arrhythmias
- Be aware of the various side effects of these agents (commonly dizziness, hypotension)
- May play a role in early detection
- Potential for increased arrhythmias with many medications & with activity
- If no EKG is available, palpation of pulse for rate & regularity may be useful
Background of congestive heart failure (CHF)
- Heart is unable to pump a sufficient quantity of blood
- Fluid accumulates in the lungs & peripheral tissues because the heart is unable to maintain proper circulation
Pathophysiology of congestive heart failure (CHF)
- Cardiac lesion -> decreased cardiac performance -> neurohumeral compensation -> increased cardiac workload -> myocardial cell changes -> decreased cardiac performance
- Vicious cycle
Systolic dysfunction of CHF
- Cardiac output is reduced
- Neurohumeral compensation activates further worsening dysfunction
- Increased preload & after load due to vasoconstriction & sodium & water retention
- Cardiac remodeling
Diastolic dysfunction of CHF
- 50% of patients have normal systolic function & cardiac output
- Left ventricle is stiff & unable to relax -> unable to fill & increased pressure
- Progressive changes in cellular function & impaired cardiac function
Signs and symptoms of CHF
- Pulmonary edema
- Pleural effusion
- Distended neck veins
- Enlarged liver & spleen
- Ankle edema
Difference between left and right sided heart failure
- Left: volume backs up in the lungs
- Right: volume backs up in peripheral tissues
Pharmacotherapy for CHF
- Inotropes (improve pumping ability of the heart): Digitalis, Phosphodiesterase inhibitors, and Dobutamine/Dopamine
- Decrease cardiac workload: ACE inhibitors/ARBs, beta blockers, loop diuretics, and vasodilators
MOA and adverse effects of Digoxin
- MOA: increase intracellular Ca facilitates interaction b/w myosin & actin filaments; directly inhibits sympathetic NS
- Adverse effects: GI distress (N/V/D); CNS disturbances (drowsiness, fatigue, confusion, visual disturbances); arrhythmias
MOA and adverse effects of phosphodiesterase inhibitors: Milrinone
- MOA: inhibit phosphodiesterase which breaks down cGMP allowing more calcium to enter the cells (increases force of contraction); vasodilates (reduces preload & afterload)
- Adverse effects: Hypotension and arrhythmias
Describe Milrinone
- IV infusion medication
- Used in more severe advanced heart failure or short term for decompensated heart failure
MOA and adverse effects of Dobutamine & Dopamine
- MOA: stimulate beta1 receptors on the myocardium which increases contractility
- Adverse effects: Hypotension and arrhythmias
Describe Dobutamine & Dopamine
- IV infusion medication
- Used in more severe advanced heart failure or short term for decompensated heart failure
List ACE inhibitors and ARBs drugs
- ACE inhibitors: Lisinopril, Enalapril, Ramipril
- ARBs: Losartan, Valsartan
MOA and adverse effects of ACE inhibitors and ARBs
- MOA: block production or activity of angiotensin II which also reduces production of aldosterone
- Adverse effects: ACE inhibitors = cough; hypotension, acute kidney injury
List beta blockers
- Metoprolol succinate
- Carvedilol
- Bisoprolol
MOA and adverse effects of beta blockers
- MOA: attenuate excessive sympathetic activity contributing to the vicious cycle
- Adverse effects: bradycardia and hypotension
List loop diuretics
- Furosemide
- Bumetanide
- Torsemide
MOA and adverse effects of loop diuretics
- MOA: increase excretion of sodium & water = reduces preload
- Adverse effects: volume depletion and electrolyte imbalances = hyponatremia, hypokalemia
List vasodilators
- Hydralazine
- Nitrates
MOA and adverse effects of vasodilators
- MOA: reduce peripheral vascular resistance to decrease amount of blood returning to the heart (preload) and pressure the heart must pump against (afterload)
- Adverse effects: headache, dizziness, hypotension, orthostatic hypotension, reflex tachycardia
Key points for PT related to congestive heart failure (CHF)
- Exercise programs for these patients result in improved exertion tolerance, endurance, & improved quality of life
- Must remain alert for signs of acute HF: cough, difficulty breathing, abnormal respiratory sounds
- Watch for signs of adverse drug events especially orthostatic hypotension
Background of coagulation disorders & hyperlipidemia
- Hemostasis: balance between too much and too little blood coagulation
- Restoration of hemostasis involves pharmacologic methods: excessive clotting = anti platelets, anticoagulants, fibrinolytics; inadequate clotting = replacing missing clotting factors
Describe anticoagulants
- Control the function & synthesis of certain clotting factors
- Prevent clot formation in the venous system
- 4 classes: heparin, warfarin, direct thrombin inhibitors, factor Xa inhibitors
List heparin agents
- Unfractionated heparin
- Low molecular weight heparin (enoxaparin)
MOA and adverse effects of heparin agents
- MOA: potentiates the activity of antithrombin - binds to several clotting factors & renders them inactive
- Adverse effects: heparin induced thrombocytopenia (HIT)
MOA and how to monitor warfarin
- MOA: interferes with Vit. K metabolism in the liver & impairs the synthesis of several clotting factors
- Monitoring: periodic INR checks
List direct thrombin inhibitors and their MOA
- Dabugatran (Oral); Bivalirudiin, Argatroban (IV)
- MOA: bind directly to the active site on thrombin & inhibit its ability to convert fibrinogen to fibrin
List factor Xa inhibitors and their MOA
- Fondaparinux (SQ); Rivaroxaban, Apixaban (PO)
- MOA: inhibit factor Xa which is the combination of the intrinsic & extrinsic pathways
Describe antiplatelets
- Inhibit abnormal platelet activity & prevent aggregation in arteries
- Help reduce incidence of myocardial infarction & ischemic stroke
MOA and adverse effects of aspirin
- MOA: suppresses platelet aggregation by inhibiting the synthesis of prostaglandins & thromboxane
- Adverse effects: GI irritation, liver and kidney toxicity
Uses for aspirin
- Limits progression of platelet induced occlusion thereby reducing the extent of damage to the myocardium in an acute MI
- Stroke
- After certain interventions: grafts, valve replacements
List ADP receptor blockers
- Clopidogrel
- Prasugrel
- Ticagrelor
MOA and uses of ADP receptor blockers
- MOA: inhibit ADP on the platelet membrane which decreases platelet activity
- Uses: myocardial infarction (MI), ischemic stroke
Describe fibriinolytics
- Facilitate destruction of blood clots
- Used to reestablish blood flow through vessels that have been occluded by thrombi: MI, ischemic stroke, and DVT/PE
- IIV médications used in emergency situations
List fiibrinolytics
- Alteplase
- Tenecteplase
- Reteplase
Adverse effects of antithrombotics
- Bleeding
Describe hemophilia
- Hereditary disease
- Unable to synthesize a specific clotting factor
- Tx: replace clotting factor either prophylactically or during acute events ($$$)
Describe vitamin K deficiency
- Insufficient ingestion or inadequate absorption
- Tx: administer exogenous vitamin K
Describe hyperlipidemia
- Chronic & excessive increase in plasma lipids
- Deposited on arterial walls forming plaque like lesions which can occlude the artery
- Rupture of these lesions leads to thrombosis & infarction
List HMG-CoA reductase inhibitors (Statins)
- Atorvastatin, Rosuvastatin
- Simvastatin, Lovastatin, Prevastatin
MOA and adverse effects of HMG-CoA reductase inhibitors (Statins)
- MOA: inhibit HMG-CoA reductase which catalyzes one of the early steps in cholesterol synthesis; decrease LDL & triglycerides; increases HDL
- Adverse effects: myalgias
List fabric acids (Fibrates)
- Fenofibrate
- Gemfibrozil
MOA and adverse effects of fabric acids (Fibrates)
- MOA: binds to a receptor to affect the transcription of genes that affect lipid metabolism; primarily decreases triglycerides
- Adverse effects: Rhabdomolysis = particularly in combination with other agents
Describe bile acid sequestrants
- Cholestyramine, colesevelam, colestipol
- Bind to bile acids within the GI tract & increase fecal excretion which accelerates cholesterol breakdown
Describe Niacin
- Decreases LDL and triglycerides; increases HDL
- Adverse effects: flushing
Describe Ezetimibe
- Inhibits cholesterol absorption in the GI tract
- Primarily decreases LDL
Key points for PTs related to coagulation disorders & hyperlipidemia
- Any procedure or technique which may induce bleeding should be done cautiously for patients on antithrombotics
- Intrajoint hemorrhage is common with hemophilia & rehab of the affected joints is necessary
- PTs can help design & implement exercise programs for weight loss to assist with hyperlipidemia therapy