Antianginal DrugsLilley Reading and Workbook – Chap 23

Supply and Demand: ◦ When the supply of oxygen and nutrients in the blood is

insufficient to meet the demands of the heart The heart requires a large supply of oxygen to

meet the demands placed on it Ischemia

◦ Poor blood supply to an organ - myocardium Ischemic heart disease

◦ Poor blood supply to the heart muscle◦ Atherosclerosis or Coronary artery disease

Myocardial infarction (MI)◦ Necrosis, or death, of cardiac tissue◦ Disabling or fatal

Chronic stable angina (also called classic or effort angina)

Unstable angina(also called preinfarction or crescendo angina)

Vasospastic angina(also called Prinzmetal’s or variant angina)

Increase blood flow to ischemic heart muscleand/or Decrease myocardial oxygen demand

Minimize the frequency of attacks and decrease the duration and intensity of angina pain

Improve the patient’s functional capacity with as few adverse effects as possible

Prevent or delay the worst possible outcome, MI

Nitrates/nitrites

(beta)-blockers

Calcium channel blockers

Available forms

Sublingual* Buccal* Chewable tablets Oral capsules/tablets Intravenous solutions Ointments* Transdermal patches* Translingual sprays* *Bypass the liver and the first-pass effect

Vasodilation due to relaxation of smooth muscles Potent dilating effect on coronary arteries Used for prevention and treatment of angina Vasodilation results in reduced myocardial

oxygen demand Nitrates cause dilation of both large and small

coronary vessels Nitrates alleviate coronary artery spasms

Result: oxygen to ischemic myocardial tissue

Rapid-acting forms◦ Used to treat acute anginal attacks◦ Sublingual tablets; intravenous infusion

Long-acting forms◦ Used to PREVENT anginal episodes

Nitroglycerin

Prototypical nitrate Large first-pass effect with oral forms Used for symptomatic treatment of ischemic

heart conditions (angina) IV form used for BP control in perioperative

hypertension, treatment of HF, ischemic pain, pulmonary edema associated with acute MI, and hypertensive emergencies

isosorbide dinitrate (Isordil, Sorbitrate, Dilatrate SR)

isosorbide mononitrate (Imdur, Monoket, ISMO)

Uses: Acute relief of angina Prophylaxis in situations that may provoke

angina Long-term prophylaxis of angina

Adverse effects Headaches

◦ Usually diminish in intensity and frequency with continued use

◦ Treated with acetaminophen Tachycardia, postural hypotension Tolerance may develop

Tolerance

Occurs in patients taking nitrates around the clock or with long-acting forms

Prevented by allowing a regular nitrate-free period to allow enzyme pathways to replenish

◦ Transdermal forms: remove patch at bedtime for 8 hours, then apply a new patch in the morning

Nursing implications

IV forms of NTG must be given with special non-PVC tubing and bags

Discard parenteral solution that is blue, green, or dark red

Follow specific manufacturer’s instructions for IV administration

Instruct patients in proper technique and guidelines for taking sublingual NTG for anginal pain

Instruct patients never to chew or swallow the SL form

Instruct patients that a burning sensation felt with SL forms indicates that the drug is still potent

Instruct patients to keep a fresh supply of NTG on hand; potency is lost in about 3 months after the bottle has been opened

Medications should be stored in an airtight, dark glass bottle with a metal cap and no cotton filler to preserve potency

Instruct patients in the proper application of nitrate topical ointments and transdermal forms, including site rotation and removal of old medication

To reduce tolerance, the patient may be instructed to remove topical forms at bedtime and apply new doses in the morning, allowing for a nitrate-free period

Instruct patients to take prn nitrates at the first hint of anginal pain

Monitor VS frequently during acute exacerbations of angina and during IV administration

If experiencing chest pain, the patient taking SL NTG should be lying down to prevent or decrease dizziness and fainting that may occur due to hypotension

If anginal pain occurs:

Stop activity and sit or lie down Take a SL tablet (as prescribed), If no relief of chest pain, call Emergency

Services/911 immediately Do not try to drive to the hospital

atenolol (Tenormin)

metoprolol (Lopressor)

propranolol (Inderal)

nadolol (Corgard)

Mechanism of action 1-receptors on the heart are blocked Decrease the HR, resulting in decreased myocardial

oxygen demand and increased oxygen delivery to the heart

Decrease myocardial contractility, helping to conserve energy or decrease demand

After an MI, a high level of circulating catecholamines irritate the heart, causing an imbalance in supply and demand ratio and even leading to life-threatening dysrhythmias. -blockers block the harmful effects of catecholamines, thus improving survival

Indications

Angina Antihypertensive Cardiac dysrhythmias Cardioprotective effects, especially after MI Some used for migraine headaches, essential

tremors, and stage fright

Adverse effectsBody System Adverse EffectsCardiovascular Bradycardia, hypotension,

second- or third-degree heart block; heart failure

Metabolic Altered glucose and lipidmetabolism

CNS Dizziness, fatigue, mental depression, lethargy,

drowsiness, unusual dreamsOther Impotence, wheezing,

dyspnea

Nursing implications Patients taking -blockers should monitor pulse rate daily

and report any rate lower than 60 beats per minute

Dizziness or fainting should also be reported

Constipation is a common problem; instruct patients to take in adequate fluids and eat high-fiber foods

These medications should never be abruptly discontinued due to risk of rebound hypertensive crisis

Inform patients that these medications are for long-term prevention of angina, not for immediate relief

Mechanism of action

Cause coronary artery vasodilation

Cause peripheral arterial vasodilation, decreasing systemic vascular resistance

Reduce the workload of the heart

Result: decreased myocardial oxygen demand

Indications

First-line drugs for treatment of angina, hypertension, and supraventricular tachycardia

Coronary artery spasms (Prinzmetal’s angina) Short-term management of atrial fibrillation and flutter Raynaud’s Phenomenon

Adverse effects

Very acceptable adverse effect and safety profile May cause hypotension, palpitations, tachycardia or

bradycardia, constipation, nausea, dyspnea (other adverse effects possible

Constipation is a common problem

Patients should: take in adequate fluids Eat high-fiber foods

Before administering, perform a complete health history to determine presence of conditions that may be contraindications for use or call for cautious use

Obtain baseline VS, including respiratory patterns and rate

Assess for drug interactions Patients should not take any medications,

including OTC medications, without checking with the physician

Patients – encourage to limit caffeine intake

Patients should report blurred vision, persistent headache, dry mouth, dizziness, edema, fainting episodes, weight gain of 2 pounds in 1 day or 5 or more pounds in 1 week, pulse rates less than 60, and any dyspnea

Alcohol consumption and hot baths or spending time in whirlpools, hot tubs, or saunas will result in vasodilation, hypotension, and the possibility of fainting

Teach patients to change positions slowly to avoid postural BP changes

Encourage patients to keep a record of their anginal attacks, including precipitating factors, number of pills taken, and therapeutic effects

Monitor for adverse reactions◦ Allergic reactions, headache, lightheadedness,

hypotension, dizziness

Monitor for therapeutic effects◦ Relief of angina, decreased BP, or both

A 62-year-old patient is having an anginal attack but avoids taking his prescribed PRN dosage of nitroglycerin.

Appropriate nursing actions would include:(Select all that apply.)

1. having him take the prescribed dose immediately.2. asking him why he avoids taking the dose as soon as the pain starts.3. giving him a thorough explanation of the purpose(s) or value of taking

the medication.4. reprimanding him severely for his hesitancy in self-administering thenitroglycerin

Instruct the patient on the proper storage of nitroglycerin to keep the medicine in:

1. a chest pocket for easy access. 2. its container for 6 months. 3. the original, dark-colored glass container. 4. its container in the refrigerator to reduce deterioration.

Calcium channel blockers reduce anginal pain by:

1. promoting vasodilatation and minimizingcellular aggregation.2. increasing the heart rate and bloodpressure.3. stimulating peripheral vasoconstriction.4. increasing peripheral resistance