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Pharmacology Exam Study Guide

Drugs for Hypertension

  • Therapeutic Classification: Antihypertensive

    • Exemplars: Diuretics, ACEIs, ARBs, CCBs, Adrenergic Antagonists/Agonists, Direct Vasodilators

Blood Pressure Determinants

  • Cardiac Output:

    • Stroke volume

    • Preload

    • Contractility

    • Afterload

    • Heart rate

    • Sympathetic nervous system activity

    • Parasympathetic nervous system activity

    • Epinephrine

  • Peripheral Resistance/Diameter of Arterioles:

    • Sympathetic nervous system activity

    • Renin/angiotensin II

    • Increase in blood viscosity

  • Blood Volume:

    • Fluid loss

    • Dehydration

    • Fluid retention

    • Aldosterone

    • ADH

Antihypertensive Medications and Mechanisms

  • Diuretics: Decrease sodium (e.g., thiazides)

  • Direct-Acting Arteriolar Dilators: diazoxide, hydralazine, minoxidil

  • Direct-Acting Arteriolar and Venous Dilator: sodium nitroprusside

  • Peripherally Acting Alpha1-Receptor Antagonists: doxazosin, prazosin, terazosin

  • Centrally Acting Alpha2-Receptor Agonists: clonidine, guanfacine, methyldopa

  • Centrally and Peripherally Acting Adrenergic Neuron Blocker: reserpine

  • Beta-Adrenergic Blocking Agents: propranolol, atenolol, etc.

  • Angiotensin-Converting Enzyme (ACE) Inhibitors: captopril, enalapril, etc.

    • Inhibit renin release

  • Angiotensin I to Angiotensin II Pathway: Decreases constriction

Symptoms of Hypertension

  • Severe Headache

  • Vision Problems

  • Difficulty breathing

  • Fatigue

  • Chest Pain

  • Pounding in Chest, Neck, or Ears

ACEIs & ARBs: Mechanism of Action

  • ACEIs prevent angiotensin I from converting to angiotensin II.

  • ARBs block receptor sites for angiotensin II.

  • ACEIs inhibit aldosterone secretion and peripheral artery constriction.

  • ARBs block the aldosterone receptor sites from working.

  • Both increase K^+ levels.

ACE Inhibitors

  • Common Drug Names:

    • benazepril (Lotensin)

    • captopril (Capoten)

    • enalapril (Vasotec)

    • fosinopril (Monopril)

    • lisinopril (Prinivil, Zestril)

    • quinapril (Accupril)

    • ramipril (Altace)

  • Recognition Clue: Generic drug names end in “pril”.

  • Side Effects:

    • Hyperkalemia

    • Orthostatic hypotension

  • Adverse Effects:

    • “1st dose phenomenon”

    • Persistent dry cough

    • Angioedema

  • Indications: HTN, HF

  • Pregnancy Category: D

  • Black Box Warning: Fetal injury & death may occur if taken during pregnancy; do not administer during lactation

Angiotensin II Receptor Blockers (ARBs)

  • Common Drug Names:

    • irbesartan (Avapro)

    • losartan (Cozaar)

    • olmesartan (Benicar)

    • valsartan (Diovan)

  • Recognition Clue: Generic drug names end in “sartan”.

  • Side Effects:

    • Hyperkalemia

    • Orthostatic hypotension

  • Adverse Effects:

    • “1st dose phenomenon” when given concurrently with ACEI

  • Indications: HTN, HF

  • Pregnancy Category: D

  • Black Box Warning: Fetal injury & death may occur if taken during pregnancy; do not administer during lactation

Calcium Channel Blockers (CCBs)

  • Selective CCBs (affect just the arteries):

    • amlodipine (Norvasc)

    • felodipine (Plendil)

    • nicardipine (Cardene)

    • nifedipine (Procardia XL)

      • Recognition Clue: Generic drugs for selective CCBs end in “pine”

  • Nonselective CCBs (affect arteries & the heart):

    • diltiazem (Cardizem)

    • verapamil (Calan)

  • Side Effects:

    • Orthostatic hypotension

    • Constipation (NS CCBs – bradycardia)

  • Administration Alerts: Do not divide, crush, or have the patient chew extended release tablets

Beta-Adrenergic Antagonists (Beta Blockers)

  • Common Drug Names:

    • atenolol (Tenormin)

    • metoprolol (Lopressor, Toprol)

    • carvedilol (Coreg)

    • labetalol (Trandate)

    • nadolol (Corgard)

    • propranolol (Inderal)

      • Recognition Clue: Generic drug names end in “olol”

  • MOA: Cardioselective vs non-cardioselective

  • Indications: HTN, MI, HF, migraines

  • Side Effects:

    • Bradycardia

    • Orthostatic hypotension

  • Patient Teaching: NEVER stop taking this med suddenly!

  • Additional Notes:

    • May cause ED

    • Monitor I & O

    • Assess for angina

    • Check breath sounds before IV administration

    • Be careful following first dose

Alpha 1-Adrenergic Antagonists

  • Common Drug Names:

    • Doxazosin (Cardura)

    • Prazosin (Minipress)

    • Terazosin (Hytrin)

      • Recognition Clue: Generic drug names end in “zosin”.

  • MOA: Blocks alpha1 receptors in vascular smooth muscle – dilating arteries & veins, as well as smooth muscle around prostate

  • Indications: HTN, BPH

  • Adverse Effects: Profound hypotension 2-6 hours following first few doses

  • Administration Alerts:

    • Monitor for 1st dose phenomenon

    • Do not divide, crush, or have the patient chew extended release tablets

Alpha 2 - Adrenergic Agonists

  • Common Drug Names:

    • clonidine (Catapres)

    • methyldopa (Aldomet)

  • MOA: Decreases outflow of sympathetic impulses from CNS to heart & arterioles, similar in effect to alpha1 antagonists – slows HR & dilates arterioles

  • Side Effects:

    • Orthostatic hypotension

    • Bradycardia

    • CNS effect: sedation

  • Nursing Responsibilities: Check BP, HR, and LOC before giving

Direct-Acting Vasodilators

  • Common Drug Names:

    • hydralazine (Apresoline)

    • Minoxidil (Loniten)

    • nitroprusside (Nipride, Nitropress)

  • Indications: HTN, HF

  • Contraindications: Angina or in the presence of an MI because it can cause reflex tachycardia

  • Adverse Effects:

    • Reflex tachycardia from sudden drop in BP

    • Sodium and water retention because of rapid drop in BP

    • Nipride can cause thiocyanate toxicity

  • Administration Alert: Abrupt withdrawal can cause rebound HTN

Nursing Responsibilities: Monitoring Parameters

  • BP: Monitor for all drug classes.

  • HR: Monitor for all drug classes except diuretics.

  • K^+: Monitor for diuretics, ACEIs, and ARBs.

Drugs for Heart Failure

Pathophysiology of Heart Failure

  • Vicious Cycle: Failing heart leads to decreased cardiac output, triggering:

    • Increased sympathetic activity (increased heart rate and force of contraction)

    • Activation of renin-angiotensin-aldosterone system (vasoconstriction and retention of Na+ and water)

    • Diminished renal blood flow (retention of Na+ and water)

    • Increased afterload, plasma volume, and cardiac workload

    • Pulmonary and peripheral edema

    • Myocardial dysfunction worsening heart failure

Signs & Symptoms of Left-Sided Heart Failure

  • Paroxysmal Nocturnal Dyspnea

  • Elevated Pulmonary Capillary Wedge Pressure

  • Restlessness

  • Confusion

  • Pulmonary Congestion

    • Cough

    • Crackles

    • Wheezes

    • Blood-Tinged Sputum

    • Tachypnea

  • Orthopnea

  • Tachycardia

  • Exertional Dyspnea

  • Fatigue

  • Cyanosis

MOA for Heart Failure Drugs

  • Diuretics: Increase cardiac output by reducing fluid volume and decreasing blood pressure (e.g., furosemide).

  • Cardiac Glycosides: Increase cardiac output by increasing the force of myocardial contraction (e.g., digoxin).

  • ACE inhibitors and angiotensin receptor blockers: Increase cardiac output by lowering blood pressure and decreasing blood volume (e.g., lisinopril).

  • Phosphodiesterase Inhibitors: Increase cardiac output by increasing the force of myocardial contraction (e.g., milrinone).

  • Vasodilators: Decrease cardiac workload by dilating vessels and reducing preload (e.g., isosorbide dinitrate with hydralazine).

  • Adrenergic blockers: Decrease cardiac workload by slowing the heart rate (\beta_1) and decreasing blood pressure (\alpha) (Example: carvedilol)

Heart Failure Drug Classes

  • ACEIs

  • ARBs

  • Diuretics

  • Cardiac Glycosides

  • BBs (Antagonists)

  • Vasodilators

  • Phosphodiesterase Inhibitors

  • Inotropic Drugs

Cardiac Glycosides: Digoxin (Lanoxin)

  • Drug of choice: HF secondary to positive inotropic properties, and for negative chronotropic and dromotropic properties

  • Also used for: Atrial fib & atrial tach

  • Contraindications: Apical pulse < 60, Hypokalemia

  • Side Effects: bradycardia

  • Adverse Effects: Often given with diuretics, monitor for hypokalemia. Concurrent use with BBs may intensify bradycardia (synergistic effect)

  • Treatment Overdose: digoxin immune fab (Digibind)

Vasodilators for HF : nesiritide (Natrecor)

  • Route: IV infusion

  • MOA: Synthetic BNP, vasodilator that decreases preload and afterload; hBNP enhances naturesis

  • Side Effect: hypotension

  • Nursing Responsibility: Check & monitor BP

Phosphodiesterase Inhibitors: milrinone (Primacor)

  • Pharmacologic Classifications: Phosphodiesterase Inhibitors

  • Route: IV infusion

  • Mechanism of Action: Blocks the enzyme phosphodiesterase in cardiac muscle, increasing the amount of calcium that can enter cells; This leads to increased inotropy and an increase in cardiac output

  • Adverse Effects: 1 in 10 patients develop ventricular tachycardia, hypotensive shock

  • Administration Alerts: Must use a microdrop set with IV pump, Continuous EKG monitoring

  • Side Effects: Hypotension

Drugs for Angina Pectoris and Myocardial Infarction

Exemplars

  • Organic Nitrates

  • BBs (Antagonists)

  • CCBs

  • Thrombolytics & Adjunct Drugs for MI

Coronary Artery Disease

  • Atherosclerosis leads to narrowing of lumen, plaque formation, and potential thrombus formation.

Acute Coronary Syndrome

  • Thrombolytic therapy should be initiated within 20 minutes to 12 hours of arrival at the hospital for a patient experiencing a myocardial infarction.

  • Large clot lodged in the left coronary artery. Tissue distal to the clot becomes inflamed and ischemic.

Organic Nitrates

  • Common Drugs:

    • nitroglycerin (Nitrostat, Nitro-dur, Nitro-Bid)

    • isosorbide dinitrate (Isordil)

    • isosorbide mononitrate (Imdur)

Nitroglycerin (Nitrostat, Nitro-Bid, Nitro-Dur)

  • Pharmacologic Class: Organic nitrate, vasodilator

  • Actions and Uses:

    • The SL form is taken while an acute angina episode is in progress or just prior to physical activity. When given sublingually, it terminates angina pain rapidly.

    • Chest pain that does not respond to SL NTG within 10 to 15 minutes after a single dose of sublingual nitroglycerin* may indicate MI, and emergency medical services (EMS) should be contacted.

    • The transdermal and oral extended-release forms are for prophylaxis only because they have a relatively slow onset of action.

  • Indications: chest pain and/or MI

  • MOA: dilates coronary arteries and veins, decreasing preload

  • Side Effect: orthostatic hypotension, headache from cerebral vasodilation

  • Adverse Effect: hypotensive shock, chest pain, MI

  • Nursing responsibility: check BP

  • Contraindications: hypotension, increased ICP

  • Administration Alerts:

    • Use gloves when applying nitroglycerin paste or ointment to prevent self-administration.

    • Drug–Drug: Concurrent use with phosphodiesterase-5 inhibitors such as sildenafil (Viagra) tadalafil (Cialis) may cause life-threatening hypotension and cardiovascular collapse.

    • Use of alcohol and other antihypertensive drugs may cause additive hypotension.

Adjunct Drugs for MI

  • ASA

  • ADP Receptor Blockers

  • Thrombolytics

  • Glycoprotein IIb/IIIa Inhibitors

  • Heparin

ASA

  • Indication: High dose ASA is given to reduce mortality related to MI

  • MOA: Inhibits platelet aggregation by inhibiting the COX-1 enzyme

  • Side effect: unusual bruising

  • Adverse effect: GI or cerebral bleeding

  • Nursing responsibility: check platelet levels

ADP Receptor Blockers

  • Indication: prevent reinfarction with an MI

  • MOA: inhibits platelet aggregation by blocking adenosine diphosphate (ADP) receptor sites

  • Side effect: unusual bruising

  • Adverse effect: GI or cerebral bleeding

  • Nursing responsibility: check platelet levels

Thrombolytics: retaplase (Retavase)

  • Indication: treatment for active MI

  • MOA: dissolves blood clots obstructing the coronary arteries, restoring blood supply to the myocardium

  • Administration Alert: Should be given within 30 minutes of arrival to ER

  • Side effect: bleeding may be prolonged at injection sites and IV catheter insertion sites

  • Adverse effect: GI or cerebral bleeding

  • Contraindication: patients with active bleeding or a recent history of hemorrhagic stroke or surgery

  • Nursing responsibility: VS, LOC, & s/s of bleeding must be monitored continuously

Glycoprotein IIb/IIIa Inhibitors

  • Indication: unstable angina or MI

  • MOA: Inhibits platelet aggregation by blocking glycoprotein IIb/IIIa proteins from adhering to each other

  • Side effect: unusual bruising

  • Adverse effect: GI or cerebral bleeding

  • Nursing responsibility: check platelet levels

Heparin

  • Indication: prevents additional thrombi from forming during an MI

  • MOA: inhibits thrombin, preventing fibrinogen from converting to fibrin

  • Side effect: unusual bruising

  • Adverse effect: GI or cerebral bleeding

  • Nursing responsibility: check platelet levels, check IV site for infiltration

Drugs for Shock

Shock Defined

  • A condition in which vital tissues and organs are not receiving enough blood flow to function properly.

  • Without adequate oxygen and nutrients, cells cannot carry out normal metabolic processes.

  • Failure to reverse the CAUSES of shock may lead to irreversible organ damage and death.

  • Shock is a medical emergency!

Common Types of Shock

  • Anaphylactic: Acute allergic reaction

    • Severe reaction to an allergen such as penicillin, nuts, shellfish, or animal proteins

  • Cardiogenic: Failure of the heart to pump sufficient blood to tissues

    • Left heart failure, myocardial ischemia, myocardial infarction (MI), dysrhythmias, pulmonary embolism, or myocardial or pericardial infection

  • Hypovolemic: Loss of blood volume

    • Hemorrhage, burns, excessive diuresis, or severe vomiting or diarrhea

  • Neurogenic: Vasodilation due to overstimulation of the parasympathetic nervous system or understimulation of the sympathetic nervous system

    • Trauma to the spinal cord or medulla, severe emotional stress or pain, or drugs that depress the central nervous system

  • Septic: Multiple organ dysfunction as a result of pathogenic organisms in the blood; often a precursor to acute respiratory distress syndrome and disseminated intravascular coagulation

    • Widespread inflammatory response to bacterial, fungal, or parasitic infection

Causes of Anaphylaxis

  • Penicillin, cephalosporins, sulfonamides

  • Nonsteroidal anti-inflammatory drugs (NSAIDs)

  • ACE inhibitors

  • Opioid analgesics and iodine-based contrast media

Initial Treatment Priorities for Shock

  • CABs of life support: Circulation, Airway, Breathing

  • Identify underlying cause, then start more specific treatment

  • Connect to a cardiac monitor, and apply a pulse oximeter

  • Administer oxygen at 15 L/min via a nonrebreather mask

  • Monitor level of consciousness

  • Keep patient warm and quiet

  • Offer psychological support (be caring!)

Pharmacologic Interventions for Shock

  • Vasopressors

    • dopamine

    • norepinephrine (Levophed)

    • epinephrine (Adrenalin)

  • Inotropic Drugs

    • dobutamine (Dobutrex)

    • dopamine - dose related

  • Fluid Replacement Agents

    • Crystalloids

    • Colloids

    • Blood Products

    • (Usually in that order!)

Fluid Replacement Agents

  • Crystalloids: Normal saline (0.9% sodium chloride), Lactated Ringer's, Hypertonic saline (3% sodium chloride), 5% dextrose in normal saline

  • Colloids: plasma protein fraction (Plasmanate), dextran 40, hetastarch (Hespan), serum albumin

  • Blood products: Whole blood, Immune globulins, Platelets, Fresh frozen plasma, Packed red blood cells.

Albumin

  • Administration Alerts: Monitor for circulatory overload or cellular dehydration. For religious reasons, some patients may refuse to accept any type of blood product, including albumin.

  • Because albumin is a natural blood product, the patient may have antibodies to the donor albumin resulting in a transfusion reaction (aka an allergic reaction). Fortunately, this does not happen often.

Blood Administration KEY POINTS

  • Determine Client's Allergies

  • Previous Transfusion Reactions

  • Verify Client's ID

  • Check the Dr's Order.

  • Check labels on blood bag & blood bank transfusion record with 2 Nurses: ABO-Group, RH Type, Client's Name, ID Blood Band, Hospital #, Expiration Date

  • Baseline vitals - (Then per policy).

  • #18G or #20G gauge needle.

  • Normal saline IV solution.

  • Blood administration set with filter.

  • Infuse Each Unit Over 2-4 Hours BUT No Longer Than 4 Hours.

  • Administer Within 30 Minutes of Receiving From Blood Bank.

  • Never Add ANY Meds to Blood Products.

  • Do NOT Warm Unless Risk of Hypothermic Response, THEN Only By Specific Blood Warming Equipment.

  • Severe reactions most likely first 15 min & first 50cc.

  • Blood tubing should be changed after 4 hours.

Blood Transfusion Reaction

Febrile Reaction:

  • Fever

  • Headache

  • Chills

  • Flushing

  • Tachycardia

  • Anxiety
    Hemolytic Transfusion Reaction:

  • Low Back Pain

  • Hypotension

  • Tachycardia

  • Fever and Chills

  • Chest Pain

  • Tachypnea

  • Hemoglobinuria

  • May Have Immediate Onset
    Allergic Reaction:
    Mild:

  • Hives

  • Pruritus

  • Facial Flushing
    Severe:

  • Severe Shortness of Breath

  • Bronchospasm

  • Anxiety
    Nursing Implications:

  • Stop Transfusion and notify Physician.

  • Change IV Tubing.

  • Treat symptoms if present-02, fluids, epinephrine as ordered.

  • Recheck crossmatch record with unit.
    Hemolytic Reactions

  • Obtain 2 blood samples distal to infusion site.

  • Obtain first UA-test for hemoglobinuria.

  • Monitor fluid/electrolyte balance.

  • Evaluate serum calcium levels.

Vasopressors & Inotropes:

  • Vasopressors:

    • dopamine

    • epinephrine [Adrenalin]

    • norepinephrine [Levophed]

  • Inotropes:

    • dobutamine [Dobutrex]

Dopamine

  • Indication: for shock

  • Pharmacologic Class: Nonselective adrenergic agonist; inotropic drug

  • Actions and Uses: Dose Dependent

    • Low dose: 1 to 5 mcg/kg/minute

      • Selectively stimulates dopaminergic receptors, especially in the kidneys, leading to increased renal blood flow and urine output.

    • Intermediate dose: 6 to 15mcg/kg/min

      • Stimulates B1-adrenergic receptors. Produces positive chronotropic and inotropic effects on the myocardium, resulting in increased heart rate and cardiac contractility.

    • High Dose: 20 mcg/kg/min and over

      • Stimulates alpha-adrenergic receptors causing vasoconstriction, causing BP to increase; further increased stimulation of B1-adrenergic receptors may increase risk of tachyarrhythmias

  • Administration Alerts:

    • Ensure the patency of the IV site prior to beginning the infusion.

    • If extravasation occurs, administer phentolamine [Regitine] to the area of infiltration as soon as possible.

  • Black Box Warning: Following extravasation, the affected area should be injected SQ with phentolamine (Regitine), an adrenergic blocker.

  • Adverse Effects: Because intermediate and high doses of dopamine have a profound effect on the cardiovascular system, patients must be continuously monitored for signs of angina, tachydysrhythmias, and severe hypertension. Dopamine is a vesicant drug that can cause severe, irreversible skin and soft tissue damage if the drug infiltrates. Can cause gangrene.

Epinephrine (Adrenalin)

  • Indications: for anaphylactic, cardiogenic, septic, and neurogenic shock states (works within minutes)

  • Pharmacologic Class: Nonselective adrenergic agonist; Sympathomimetic

  • MOA: (works within minutes)

    • Stimulates both alpha and beta adrenergic receptors:

      • alpha1 receptors ® arterial vasoconstriction

      • beta2 receptors ® relaxes smooth muscle in the bronchi, opening the airways

      • beta1 receptors ® CO & HR

  • Side effects: hypertension, tachycardia

  • Adverse effects: IV extravasation, hypertensive emergency, tachydysrhythmias

  • Nursing Responsibilities: Start infusion only after ensuring the patency of the IV. Monitor BP, HR, and EKG rhythm

  • Contraindications: In life-threatening conditions such as anaphylaxis, there are no absolute contraindications for the use of epinephrine.

Norepinephrine (Levophed)

  • Indications: acute cardiogenic shock, cardiac arrest. Vasopressor of choice for septic shock

  • Pharmacologic Class: Nonselective adrenergic agonist; sympathomimetic

  • MOA: acts directly on alpha-adrenergic receptors in the vascular smooth muscle, immediately raising blood pressure.

  • Contraindications: norepinephrine should not be administered to patients who are experiencing hypotension due to hypovolemia because peripheral vasoconstriction already exists in such patients. see adverse effects

  • Side effects: HTN

  • Adverse effects:

    • Norepinephrine may cause severe peripheral and visceral vasoconstriction ® tissue hypoxia, ischemia, and infarction

      • Renal effects: decreased urine output ® oliguria

      • Mesenteric effects: absent bowel sounds (often leads to sepsis ® septic shock)

      • Peripheral vasculature: thrombi, emboli

  • Nursing Responsibilities:

    • Start infusion only after ensuring the patency of the IV.

    • If extravasation occurs, administer phentolamine (Regitine) to the area of infiltration as soon as possible.

    • Norepinephrine is a powerful vasoconstrictor; continuous monitoring of the patient’s blood pressure is required to prevent the development of hypertension.

    • Pregnancy category D

Dobutamine (Dobutrex)

  • Indication: Cardiogenic shock

  • Pharmacologic Class: Selective beta-1 adrenergic agonist

  • MOA: Stimulates beta-1 receptor sites by increasing myocardial contraction and cardiac output. Drug of choice for severe HF.

  • Side effects: hypertension, tachycardia

  • Adverse effects: IV extravasation, hypertensive emergency, tachydysrhythmias

Drugs for Dysrhythmias

Normal Electrical Conduction Through The Heart

  • The cardiac action potential [AP] is responsible for generating and conducting electrical impulses through the heart

  • Automaticity is the ability of specialized cells in the heart to generate an AP

  • Electrical activity always precedes mechanical activity

The Cardiac Action Potential

  • Class I: Sodium channel blockers

    • Procainamide

  • Class II: Beta-adrenergic blocker

    • Propranolol

  • Class III: Potassium channel blockers

    • Amiodarone

  • Class IV: Calcium channel blockers

    • Verapamil

Mechanisms of Action and Effects on Action Potential

  • Class I (Ia, Ib, Ic): Na+ Channel Blockade

    • Slows depolarization in fast AP cells

  • Class II: Beta Receptor Blockade

    • Slows depolarization in slow AP cells

  • Class III: K+ Channel Blockade

    • Prolongs action potential

  • Class IV: Ca2+ Channel Blockade

    • Slows depolarization in slow AP cells

Exemplars of Antidysrhythmic Classes

  • Class I: Sodium Channel Blockers

  • Class II: Beta-adrenergic Blockers

  • Class III: Potassium Channel Blockers

  • Class IV: Calcium Channel Blockers

Class I Antidysrhythmics: Sodium Channel Blockers

  • Indications: Atrial fibrillation and ventricular tachycardia

  • MOA: Slows conduction velocity, delays repolarization

  • Prototype drug: Procainamide IV (lidocaine IV is also used)

Class II Antidysrhythmics: Beta Adrenergic Blockers

  • Indication: tachydysrhythmias occurring above the ventricles caused by sympathetic stimulation

  • MOA: non-selective beta-blocker

  • Prototype drug: propranolol (Inderal)

Class III Antidysrhythmics: Potassium Channel Blockers

  • Indications: a-fib and resistant v-tach related to HF

  • MOA: prolongs atrial and ventricular repolarization

  • Prototype drug: amiodarone (Cordarone)

  • Side effects: bradycardia ® hypotension; blue-gray lips or skin

  • Contraindications: bradycardia, hypokalemia

  • Pregnancy Category: D

Class IV Antidysrhythmics: Non-Selective Calcium Channel Blockers

  • Indications: slows conduction velocity and decreases sinus or atrial tachydysrhythmias

  • MOA: inhibits influx of calcium during action potential, slowing heart rate and decreasing contractility

  • Prototype drug: verapamil (Calan)

  • Side effects: bradycardia, orthostatic hypotension, constipation

  • Adverse effects: symptomatic bradycardia

  • Contraindications: heart failure, severe bradycardia or hypotension

Miscellaneous Antidysrhythmics: Atropine Sulfate

  • Class: Anticholinergic

  • Indications: Symptomatic bradycardia

  • Route: IVP

  • SE: Urinary retention

  • AE: Tachycardia

Miscellaneous Antidysrhythmics: Adenosine (Adenocard)

  • Class: Antiarrhythmic

  • Indications: SVT that does not respond to vagal maneuvers

  • Route: Rapid IVP (half-life of 6 seconds)

  • SE: brief episode of asystole or severe bradycardia