2.Unstable (preinfarction). Unstable angina occurs over the course of a day
with progressive severity and is caused by the narrowing or partial occlu-
sion of coronary arteries. This often indicates an impending heart attack—
a medical emergency.
3.Variant (Prinzmetal, vasospastic). Variant angina occurs at rest and is due
to a vessel spasm (vasospasm).Stress tests, cardiac profile laboratory tests, and cardiac catherization may be
needed to determine the degree or blockage in the coronary arteries. A combina-
tion of pharmacologic and nonpharmacologic measures (avoiding heavy meals,
smoking, extremes in weather changes, strenuous exercise, and emotional stress)
is necessary to control and prevent anginal attacks. Proper nutrition, moderate
exercise, adequate rest, and relaxation techniques may be used to prevent attacks.Antianginals
Nitrates
Nitrates reduce venous tone resulting in decreased workload of the heart and
increased vasodilation. These are used to treat variant angina pectoris. The most
commonly prescribed nitrate is nitroglycerin. There are various types of organic
nitrates. Isosorbide dinitrate (Isordil, Sorbitrate) can be administered sublin-
gually (SL) by tablets and orally by chewable tablets, immediate release tablets,
sustained-release tablets, and capsules. Isosorbide mononitrate (Monoket, Imdur)
can be given orally by immediate-release or sustained-release tablets.Beta-Blockers
Beta-blockers (see Chapter 15) decrease the workload of the heart and decrease
the heart’s oxygen demands. Beta-blockers include atenolol (Tenormin), meto-
prolol tartrate (Lopressor), nadolol (Corgard), and propranolol HCl (Inderal)Calcium Channel Blockers
Calcium channel blockers decrease the workload of the heart and decrease the
heart’s oxygen demands and are used to treat variant angina pectoris. Calcium chan-
nel blockers include amlodipine (Norvasc), bepridil HCl (Vascor), and diltiazem
HCl (Cardizem), Felodipine (Plendil), and verapamil HCl (Calan, Isoptin).
See nitrates and calcium channel blockers in the Appendix. Detailed tables
show doses, recommendations, expectations, side effects, contraindications, and
more; available on the book’s Web site (see URL in Appendix).(^352) CHAPTER 19 Cardiac Circulatory Medications