Transcript Adverse effects

Antianginal Drugs
Lilley 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 muscle
and/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
b(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
 b1-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. b-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 effects
Body System
Adverse Effects
Cardiovascular
Bradycardia, hypotension,
second- or third-degree heart
block; heart failure
Altered glucose and lipid
metabolism
Metabolic
CNS
Other
Dizziness, fatigue,
mental depression, lethargy,
drowsiness, unusual dreams
Impotence, wheezing,
dyspnea
Nursing implications





Patients taking b-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 the
nitroglycerin







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 minimizing
cellular aggregation.
2. increasing the heart rate and blood
pressure.
3. stimulating peripheral vasoconstriction.
4. increasing peripheral resistance