1. Agents that Dilate Coronary Blood Vessels

2.  Coronary artery disease (CAD) results from atherosclerosis  Clinical symptoms caused by  narrowing of the vessels  inadequate delivery of blood, nutrients, and oxygen  Localized muscle injury  Increased lactic acid.18 - 2

3.  Pain produced (angina pectoris)  When the supply of oxygen and nutrients in the blood is insufficient to meet the demands of the heart, the muscle aches  Aggravated with stress or exercise  Drugs treat by dilating coronary blood vessels 18 - 3

4.  Angina pectoris : chest pain  affects ~ 9.8 million Americans/year  More prevalent in older men  The more vessels involved, the poorer the prognosis.18 - 4

5.  Used to treat coronary artery disease  Coronary artery disease: inadequate delivery of blood, nutrients, and oxygen to the tissues 18 - 5

6.  Three main objectives: ◦ Minimize frequency, duration, and intensity of episodes ◦ Offer few side effects ◦ Prevent myocardial infarction—death.18 - 6

7.  Increase blood flow to ischemic heart muscle  Decrease myocardial oxygen demand 18 - 7

8.  Minimize the frequency of attacks  Improve the client’s functional capacity  Prevent or delay heart disease. 18 - 8

9.  Acetylsalicylic acid (ASA)  Nitrates  Calcium channel blockers  Beta blockers  Angiotensin II receptor blockers.18 - 9

10.  Nitroglycerine ◦ Forms: sublingual, buccal, chewable, tablets, ointments, patches, spray, and intravenous. 18 - 10

11.  Causes central and peripheral vasodilatation ◦ Relaxes smooth muscles  Potent dilating effect on coronary arteries  Used for prophylaxis and acute treatment of angina. 18 - 11

12.  Large first-pass effect when taken orally  Transdermal—very effective  IV form effectively used for: ◦ Hypertension ◦ Congestive heart failure ◦ Ischemic pain, myocardial infarction ◦ Pulmonary edema. 18 - 12

13.  Do not leave the patient when he or she is changing positions after starting a new prescription for nitro ◦ Nitroglycerin is intended to cause rapid vasodilation -> dizziness with position change ◦ Nitro paste: remove med from patient’s skin and wash/dry before reapplying ◦ Always wear gloves when applying nitro topically 18 - 13

14.  Example of long-acting nitrate ◦ Isosorbide dinitrate (Isordil)  Provides: ◦ Acute relief of angina ◦ Long-term prophylaxis of angina. 18 - 14

15. . 18 - 15 Headache  Diminish in intensity and frequency with use Tachycardia Postural hypotension Dermatitis Tolerance

16.  Long-acting form can become ineffective  Solution ◦ Remove patch or cream at night for 8 hours ◦ Take the oral form for 16 hours a day. 18 - 16

17.  Additive hypotension with use of: ◦ Alcohol ◦ Beta blockers ◦ Calcium channel blockers ◦ Phenothiazines. 18 - 17

18.  Reduces calcium ion influx: ◦ Reduction of myocardial oxygen consumption ◦ Coronary artery dilation  Example: Verapamil  Side effects ◦ Dizziness, flushing, supraventricular arrhythmias. 18 - 18

19.  Block the beta receptors ◦ Reduce heart rate ◦ Reduce contractility ◦ Reduce blood pressure  Example ◦ Atenolol  Side effects ◦ Flushing, bradycardia, and bronchospasm 18 - 19

20.  Angiotensin II receptor blockers ◦ Block adrenergic receptors, or ◦ Direct action  Interfere with epinephrine action  Sympathetic nervous system is not stimulated ◦ Result: decreased blood pressure  Side effects ◦ Orthostatic hypotension 18 - 20

21.  Inhibits platelet clumping ◦ Given as a preventive agent ◦ Given when a person is experiencing a myocardial infarction 18 - 21

22.  Patients should carry ID  Teach smoking/tobacco cessation, med use  Assess angina attacks  Teach: nitroglycerine (NTG) most effective when taken at the beginning of an angina episode 18 - 22

23.  Teach: replace sublingual NTG Q 3 months  IV NTG requires special preparation: glass, not plastic  Give beta-blocking agents before vasodilators  Monitor blood pressure routinely 18 - 23