Pharmacology Quiz: Antiplatelet & Medication Safety

Pharmacology for Pharmacy Technicians, 4th Ed

• The book is written by Kathy Moscou PhD RPh MPH and Karen Snipe CPHT AS BA MEd
• Copyright is held by Elsevier Inc.
• All rights reserved, including those for text and data mining, AI training, and similar technologies

Chapter 19: Treatment of Heart Disease and Stroke

• The chapter covers treatment of heart failure, myocardial infarction, and stroke
• Students will learn terminology related to heart failure, myocardial infarction, and stroke
• Risk factors will be listed for heart failure, myocardial infarction, and stroke
• The symptoms of each condition will be listed
• Medications used to treat the conditions and hyperlipidemia will be categorized.
• Mechanisms of action for these medications will be described
• Warning labels and messages for these medications will be identified

Key Terms

• Antiplatelet/Anticoagulant/Antithrombotic/Atherosclerosis/Atherothrombosis
• Automaticity/Cholesterol
• Ejection fraction/Heart Failure
• HDL/Hyperlipidemia/LDL/Triglycerides
• Ischemia/Myocardial Infarction
• Tissue plasminogen activator
• Natriuretic peptides/PTT/Plaque/Platelets
• Prothrombin Time
• Thrombolytic
• Transient ischemic attack

Heart Diseases

• Heart failure: The heart is unable to pump blood at the rate needed to meet the body's metabolic needs
• Myocardial infarction (MI) (Heart attack): A sudden loss of blood supply to the heart, which damages the heart muscle.
• Angina: Chest pain or discomfort caused by a temporary disruption in blood and oxygen flow to the heart. Could be a sign of an MI.
• Stroke: Brain cells deprived of oxygen or damaged by sudden bleeding into the brain

Heart Failure Overview (1 of 2)

• Risk factors include kidney dysfunction, diabetes, ischemic heart disease, hypertension, hypothyroidism, hyperthyroidism, bradyarrhythmia/tachyarrhythmia, pulmonary embolism, HIV/AIDS, and Myocardial infarction.

Heart Failure Overview (2 of 2)

• Lifestyle factors are also risk factors for heart failure. These include excessive salt consumption, excessive alcohol consumption, and lack of physical activity.
• NSAIDs can worsen edema and interfere with the effect of drugs used to treat heart failure.

Pathophysiology of Heart Failure (1 of 3)

• Left-sided heart failure: The heart is unable to adequately pump blood to the rest of the body, resulting in lower ejection fraction and reduced volume of oxygen/nutrient-rich blood. This can cause pulmonary edema and shortness of breath.
• Right-sided heart failure: The heart's ability to pump blood to the lungs is reduced, potentially accompanied by swelling in the legs and ankles, fatigue, and weight gain from fluid accumulation

Pathophysiology of Heart Failure (2 of 3)

• Left-sided heart failure may include systolic heart failure. Ventricular contractions, stroke volume, and cardiac output can be reduced. Ejection fraction is decreased.
• Left-sided heart failure may also include diastolic heart failure. The left ventricle loses the ability to relax normally due to stiff muscle. This decreases stroke volume and cardiac output. Ejection fraction is preserved

Pathophysiology of Heart Failure (3 of 3)

• Compensatory mechanisms include the renin-aldosterone-angiotensin system being activated.
• There is an increase in blood volume and cardiac output.
• Chronic sympathetic nervous system activity increases heart rate.
• Natriuretic peptides such as atrial natriuretic peptide and brain natriuretic peptide are released. Their action promotes sodium and water elimination, vasodilation, and diastolic relaxation

Drugs Used to Treat Heart Failure

• Cardioglycosides/Diuretics/Aldosterone antagonists/Beta blockers/ACE inhibitors/Angiotensin II receptor blockers/HMG CoA reductase inhibitors/Vasodilators

Cardioglycosides

• Digoxin is the only commercially available cardioglycoside.
• It comes in capsules, tablets, elixir, and parenteral solution.
• It's derived from the foxglove plant.
• It reduces hospitalizations and increases exercise tolerance, but does not increase patient survival

Cardioglycosides: MOA

• Digoxin has a positive inotropic effect on the heart.
• It increases the force of myocardial contractions.
• It increases cardiac output.
• It decreases compensatory sympathetic activity.

Cardioglycosides: Adverse Effects

• Digoxin may cause diarrhea, constipation, nausea, vomiting, fatigue, weakness, visual disturbances (altered color perception, hazy vision), photophobia, impotence, and gynecomastia.

Digoxin Toxicity

• Digoxin has a narrow therapeutic index.
• Signs of digoxin toxicity include arrhythmia, dizziness, headache, convulsions, delusions, and coma.

Warning Labels: Cardioglycosides

• Take digoxin as directed; do not skip or exceed the dosage.
• If a dose is missed, take it as soon as possible, unless the next dose is scheduled within 12 hours.

Diuretics: Info and MOA

• Diuretics treat volume overload.
• They reduce blood pressure.
• They reduce pulmonary edema and peripheral swelling.

Aldosterone Antagonists: Info and MOA

• These agents decrease sodium and water levels.
• They increase potassium levels.
• They are used as adjunct therapy for hypertension and congestive heart failure.

Beta Blockers: Info and MOA

• Beta blockers block excess sympathetic stimulation induced by heart failure.
• They reduce heart rate and lower peripheral arterial resistance.
• They decrease cardiac workload and reduce left ventricular hypertrophy.

Beta Blockers: Adverse Effects

• Potential adverse effects include dizziness, fatigue, bradycardia, hypotension, impotence, heart block, and palpitations

ACEI, ARBs, HMG CoA Reductase Inhibitors and Vasodilators

• ACE inhibitors and ARBs are shown to reduce mortality.
• They may reduce left ventricular hypertrophy, improve diastolic filling, and increase cardiac output and reduce peripheral vascular resistance.
• ARBs improve exercise tolerance and diastolic filling in patients with heart failure.
• HMG CoA reductase inhibitors (statins) reduce inflammation caused by heart failure.
• Vasodilators reduce peripheral resistance, cardiac preload, and cardiac afterload.

Stroke Overview

• Stroke is the third leading cause of death in the US.
• Stroke occurs when blood supply to the brain is interrupted.
• Myocardial infarction occurs when blood supply to the heart is interrupted.
• Transient ischemic attacks (mini-strokes) can occur.
• About 25% of stroke patients experience a second stroke within 5 years of the first.

Types of Stroke

• Ischemic
• Thrombotic
• Embolic
• Hemorrhagic
• Transient ischemic attack

Stroke

• Recognize the warning signs using the acronym FAST (Face, Arms, Speech, Time)

Symptoms of Stroke (1 of 3)

• Limbs: Numbness or weakness of arms and legs, difficulty walking, or loss of balance or coordination

Symptoms of Stroke (2 of 3)

• EENT: Facial numbness or weakness, impaired speech, or impaired vision

Symptoms of Stroke (3 of 3)

• Cognitive: Confusion or difficulty understanding speech
• Other: Dizziness or severe headache

Symptoms of Myocardial Infarction

• Timing: Sudden onset, lasts longer than 30 minutes; angina occurs after exercise, 1-5 minutes, rest may relieve symptoms, may occur at rest
• Location: Mid-chest radiating to jaw, neck, arms, and epigastric area
• Quality: Severe squeezing or heaviness in chest area; heaviness, chest tightness, indigestion

Pathophysiology of Stroke and Myocardial Infarction

• Blood supply to brain/heart is interrupted
• Damage and death to cells occurs
• Atherosclerosis
• Atherothrombosis

Risk Factors for Stroke and Myocardial Infarction

• Nonmodifiable: Age, gender, and family history.
• Modifiable: Lifestyle, hypertension, atrial fibrillation, high cholesterol, infection.

Treatment of Stroke and Myocardial Infarction

• Clots that form in arteries may dislodge and obstruct blood and oxygen supply to the brain or heart
• Drugs that control hemostasis (process of stopping blood flow)
• Prevention of clot formation
• Dissolution of clots
• Antiplatelets (inhibit platelets)
• Anticoagulants (lessen coagulation)
• Fibrinolytic agents (dissolve existing clots)

Drugs That Control Hemostasis: Antiplatelets

• Aspirin
• Clopidogrel
• Dipyridamole
• Ticlopidine
• Abciximab
• Eptifibatide
• Tirofiban

Antiplatelet Drugs: MOA (1 of 2)

• Aspirin: Blocks the enzyme cyclooxygenase, reduces plaque formation, inhibits platelet aggregation.
• Glycoprotein IIb/IIIa inhibitors: Block the final pathway of platelet aggregation.

Antiplatelet Drugs: MOA (2 of 2)

• Ticlopidine and Clopidogrel: Interfere with platelet adhesion and aggregation; decrease the concentration of fibrinogen
• Dipyridamole: Inhibits platelet aggregation, is a coronary vasodilator

Antiplatelet Drugs: Adverse Reactions

• Bleeding, skin rash or itching, stomach pain, pain at injection site (abciximab), difficulty breathing, dizziness, weakness, joint pain, bone-marrow toxicity

Drugs That Control Hemostasis: Anticoagulants

• Warfarin
• Dalteparin
• Enoxaparin
• Heparin
• Tinzaparin
• Fondaparinux
• Argatroban
• Dabigitran

Anticoagulants: MOA

• Increase activity of antithrombin III.
• Inhibit common pathway of clotting factors Xa and Ila.
• Prevent clot formation
• Warfarin interferes with formation of vitamin K-dependent clotting factors.

Anticoagulants: Adverse Reactions

• Fever, difficulty breathing, dizziness/fainting, irritation or bleeding at injection site, rash or red spots on skin, itching or bruising, pain in back or stomach, cold/painful hands and feet; bleeding gums or in eye, nosebleeds, heavy menstrual bleeding, coughing up blood

Drugs That Control Hemostasis: Thrombolytics/Fibrinolytics

• Alteplase
• Reteplase
• Tenecteplase

Thrombolytics: MOA

• Thrombolytics increase the activity of plasmin.
• They dissolve blood clots.
• They work rapidly

Thrombolytics: Adverse Reactions

• Nausea, vomiting, hypotension, transient arrhythmia, allergic reaction, fever, bruising and bleeding in GI tract, genitourinary tract, mouth, gums, and brain

Drugs That Treat Hyperlipidemia

• HMG CoA reductase inhibitors:
  • Atorvastatin
  • Fluvastatin
  • Lovastatin
  • Pravastatin
  • Rosuvastatin
  • Simvastatin
  • Pitavastatin

HMG CoA Reductase Inhibitors: MOA

• Interfere with steps in lipid metabolism pathway.
• Reduce LDLs and triglycerides.
• Increase LDL clearance.

HMG CoA Reductase Inhibitors: Adverse Reactions

• Diarrhea, gas, headache, joint pain, nausea/vomiting, stomach pain, tiredness, myositis, liver dysfunction, rhabdomyolysis

Look-Alike/Sound-Alike Drugs

• Plavix and Paxil
• Ticlid and Tequin
• Lovenox, Lanoxin, Avonex, Luvox, Levaquin, and Lotronex
• Coumadin, Cardura, Cordarone, Kemadrin, and Ambien
• Activase and Altace
• Atorvastatin and pravastatin
• Lipitor and Zocor
• Fluvastatin and fluoxetine
• Lovastatin and Lotensin
• Lopid, Levbid, Lorabid, and Slo-bid

Common Endings

• Common endings for thrombolytic drugs are "-plase" and "-kinase."
• All HMG-CoA inhibitors have the common ending "-statin."

Fibric Acid Derivatives, Bile Acid Sequestrants, and Nicotinic Acid Derivatives

• Fibric acid derivatives: Gemfibrozil, fenofibric acid, fenofibrate
• Bile acid sequestrants: Cholestyramine, colesevelam, colestipol, ezetimibe
• Nicotinic acid derivative: Niacin

Fibric Acid Derivatives, Bile Acid Sequestrants, and Nicotinic Acid Derivatives: MOA

• Fibric acid derivatives increase clearance of VLDL. They lower body levels of fat-soluble vitamins such as A, D, E, and K.
• Bile acid sequestrants lower body levels of fat-soluble vitamins A, D, E, and K; promote intestinal clearance of cholesterol
• Nicotinic acid derivatives are lipid-lowering agents and increase HDL.

Warning Labels: Antiplatelet Drugs (1 of 2)

• Do not shake
• Avoid aspirin, NSAIDs, and other OTC medications without supervision.
• Refrigerate at 2° to 8° C. Do not freeze (abciximab, eptifibatide, tirofiban)
• Stable at room temperature for 24 hours; discard diluted solutions within 24 hours (eptifibatide, tirofiban)

Warning Labels: Antiplatelet Drugs (2 of 2)

• Take on an empty stomach (clopidogrel, dipyridamole)
• Take with a full glass of water (dipyridamole)
• Report signs of bleeding (ticlopidine)
• Take with food (aspirin and ticlopidine)
• Avoid pregnancy (3rd trimester) (aspirin)

Warning Labels: Thrombolytics

• Refrigerate reconstituted solution (2° to 8° C)
• Stable for 24 hours after reconstitution (under refrigeration)
• Do not shake

Warning Labels: Drugs That Treat Hyperlipidemia

• Avoid grapefruit juice
• Avoid alcohol
• Avoid pregnancy
• Swallow whole; don't chew (extended release)

Warning Labels: Fibric Acid Derivatives

• May cause drowsiness
• Avoid prolonged exposure to sunlight
• Take on an empty stomach (gemfibrozil)

Warning Labels: Bile Acid Sequestrants

• Take 1 hour before or 4 hours after other drugs
• Reconstitute with 2 to 6 ounces liquid—shake well
• Swallow whole (colesevelam)
• Take with 1/2 glass water and food (colesevelam)

Warning Labels: Nicotinic Acid Derivatives

• Avoid alcohol (niacin)
• Take with food (niacin)

Questions?