21 Drugs Used to Treat Cardiovascular Conditions

Cardiac Drugs Broadly classified according to effects on heart: Rate of heartbeat Rhythm of heartbeat Amount of blood output Strength of contraction

Cardiovascular System Pulmonary circulation: picks up oxygen, discards carbon dioxide Systemic circulation (including coronary circulation): carries oxygen and nutrients to all active cells and transports wastes to kidneys, liver, and skin for excretion

Heart Muscular pump with three layers: Endocardium (thin inner lining) Myocardium (heart muscle) Epicardium (thin outer lining)

Figure 21-1 Anatomy of the heart.

Figure 21-2 Electrical conduction system of the heart.

Coronary Heart Disease (CHD) Ischemia: oxygen delivered to heart is insufficient to meet needs Coronary artery disease: atherosclerosis and arteriosclerosis Angina pectoris: episodic, reversible oxygen insufficiency Classical, variant, unstable

Coronary Artery Disease Video Click on the screenshot to view a video on the topic of coronary artery disease. Back to Directory

Table 21-1 Organonitrates and Other Anginal Medications

Table 21-1 (continued) Organonitrates and Other Anginal Medications

Nitroglycerin (Nitrostat): Uses Dilates blood vessels in vascular smooth muscles to decrease cardiac oxygen demand; also relaxes spasms of variant angina Used to treat stable and variant angina

Nitroglycerin: Adverse Effects Headache Hypotension Tachycardia

Nitroglycerin: Contraindications Hypertrophic cardiomyopathy, pronounced hypovolemia, inferior MI, raised intracranial pressure, and cardiac tamponade Contraindicated in pregnancy and lactation

Nitroglycerin: Patient Information Advise patients to avoid carrying nitroglycerin close to body and to store in cool, dark place. Advise patients to avoid alcohol. Instruct patients to seek emergency medical attention if pain continues after 3 tablets. Discard unused tablets after 6 months.

Nitroglycerin Nitroglycerin can cause severe hypotension. People should use nitroglycerin with caution if they: Are taking diuretic medication Have hypertension

Other Anginal Agents Isosorbide dinitrate and isosorbide mononitrate: longer-acting antianginals Erythrityl tetranitrate: principal use is prophylaxis of angina in acute situations Pentaerythritol tetranitrate: long-acting organic nitrate for prophylaxis of angina, but not for acute attack

Beta-Adrenergic Blockers Beta-blockers (propranolol, atenolol) reduce heart’s oxygen demand by decreasing heart rate. Prevent development of myocardial ischemia and pain

Calcium Channel Blockers Interfere with movement of calcium ions through cell membranes Can affect heart or peripheral vasculature Used to treat pain of angina and to lower blood pressure

Myocardial Infarction Caused by severe, prolonged lack of oxygen, which kills an area of heart muscle Leading cause of death in industrialized nations CAD, clot formation in the coronary artery, spasm of arteries, heavy exertion, abrupt increase in blood pressure can all cause MI.

Therapeutic Agents for MI Goal is to limit damage to myocardium IV fluids Nitroglycerin Aspirin and thrombolytic drugs Morphine sulfate Beta-blockers and calcium channel blockers Oxygen

Table 21-2 Various Dysrhythmias

Table 21-3 Antidysrhythmic Medications

Table 21-3 (continued) Antidysrhythmic Medications

Table 21-3 (continued) Antidysrhythmic Medications

Table 21-3 (continued) Antidysrhythmic Medications

Quinidine (Quinidex): Uses Depresses myocardium and conduction system to decrease contractile force of heart and slow heart rate Used to treat atrial fibrillation and flutter and ventricular tachycardia

Quinidine: Adverse Effects Common: diarrhea, flatulence, abdominal pain, fever, reduced platelet, liver function abnormalities Serious: sudden ventricular fibrillation

Quinidine: Contraindications Contraindicated in pregnancy, lactation, bacterial endocarditis, myasthenia gravis Interacts with digoxin, amiodarone, verapamil

Quinidine: Patient Information Instruct patients to immediately report chest pain or a change in heart rhythm. Advise patients to take with food and to report diarrhea to health-care provider.

Propranolol (Inderal): Uses Affects beta receptors to slow heart rate and lower blood pressure Used to treat tachycardia, hypertension, angina, and to prevent MI

Propranolol: Adverse Effects Hypotension and bradycardia Diminished sex drive Impotence

Propranolol: Contraindications Contraindicated in bronchial asthma or bronchospasm, severe chronic obstructive airway disease, allergic rhinitis, pregnancy Interacts with clonidine, cimetidine, epinephrine, insulin

Propranolol: Patient Information Warn patients not to discontinue abruptly. Tell patients to monitor pulse and report a rate less than 60 bpm. Advise patients to rise slowly from a lying or sitting position to avoid dizziness.

Amiodarone: Uses Blocks potassium and sodium ion channels to prolong heart’s resting stage Used to treat atrial dysrhythmias in patients with heart failure

Amiodarone: Adverse Effects Common: dizziness, nausea, vomiting, anorexia, bitter taste, weight loss, numbness of fingers and toes Serious: pulmonary fibrosis with long-term use

Amiodarone: Contraindications Contraindicated in severe liver disease, pregnancy, severe sinus bradycardia, and in children Interacts with many drugs including digoxin and phenytoin

Amiodarone: Patient Information Advise patients to immediate report shortness of breath, cough, change in heart rate and rhythm, or vision changes. Advise patients to protect skin and eyes from sun. Instruct patients to change positions slowly to avoid dizziness.

Verapamil (Calan, Isoptin): Uses Acts primarily on AV node to slow conduction, causing depression of myocardial contractibility and dilation of coronary arteries Used to stabilize dysrhythmias and to treat angina and hypertension

Verapamil: Adverse Effects Dizziness or vertigo Emotional depression Sleepiness Headache Peripheral edema Hypotension Nausea Constipation

Verapamil: Contraindications Contraindicated in patients with hypotension and CHF and in pregnancy and lactation Interacts with carbamazepine, lithium, cyclosporine, digoxin, calcium salts

Verapamil: Patient Information Instruct patients to monitor blood pressure and report if less than 90/60 mm Hg. Advise patients to report breathing difficulty or change in heart rhythm. Instruct patients to take with food and to increase fiber intake.