Ch. 42 - Cardiac Glycosides

Question 1

Drugs Affect Cardiac Function By:

Answer 1

Inotropic = contraction

Chronotropic = heart rate

Dromotropic = electrical impulses

Question 2

Cardiac Glycosides (1):

Answer 2

Digoxin & similar drugs:
-Foxglove plant (digitalis)

Mainly used to treat CHF

Question 3

Cardiac Glycosides (2):

Answer 3

Positive inotropic action:
1.) Increases force of heart contraction 

2.) Increase mechanical efficiency size of heart decreases

Question 4

Cardiac Glycosides (3):

Answer 4

Positive inotropic action:
3.) Increases blood flow to kidneys 

4. ) Diuretic effect 
5. ) Relieves Na+ & water retention

Question 5

Cardiac Glycosides (4):

Answer 5

Negative chronotropic action:
-Slows heart rate

Tx: CHF, arrhythmias

Question 6

Selecting Appropriate Drug:

Answer 6

*Different manufacturers –> different availability of drug from tablets

Stay with same brand

Question 7

Two main drugs:

Answer 7

1. ) digitoxin:
   - Very long
   - Seldom prescribed
2. ) digoxin (Lanoxin)
   - Commonly used

DON’T CONFUSE THE TWO!

Question 8

digoxin (Lanoxin):

Answer 8

• Antiarrhythmic and blood pressure support

- It can treat heart failure and heart rhythm problems.

Question 9

digoxin (Lanoxin) – Dosage:

Answer 9

Digitalization:
-Po: 0.5 – 1mg in 2 divided doses

Maintenance:
- Po: 0.125 – 0.5 mg/day

Question 10

digoxin (Lanoxin) — Monitoring:

Answer 10

Low therapeutic index
- Monitor clients!

Therapeutic blood levels:
- 0.8 – 2 ng/mL

Question 11

digoxin (Lanoxin) — S/S Drug Toxicity:

Answer 11

GI distress:
-N/V, diarrhea, abd pain

Neurological effects:
-Visual disturbances, Restless, HA

Cardiac effects

Question 12

Predisposing Factors to Toxicity:

Answer 12

Hypokalemia
Renal impairment
IV drug administration

Question 13

digoxin — Antidote for Severe Intoxication:

Answer 13

Digoxin immune fab:

- Binds with digoxin
- Forms complex molecules 
- Excreted in urine

Question 14

Nursing Process (1) — digoxin:

Answer 14

Check apical pulse for 1 min before adm:

-Do NOT adm if pulse rate

Question 15

Nursing Process (2) — digoxin:

Answer 15

Monitor serum digoxin level:

• Normal range = 0.8 – 2 ng/ml
• Toxic = > 2 ng/ml

Question 16

Nursing Process (3) — digoxin:

Answer 16

If toxicity suspected –> anticipate serum drug levels

Antidote:
-Digoxin Immune Fab

Question 17

Nursing Process (4) — digoxin:

Answer 17

Monitor serum potassium level:
-Normal range = 3.5 – 5.3 mEq/l

Report hypokalemia

Question 18

Teaching (3) — digoxin:

Answer 18

Diet:

-Encourage foods high in potassium

Question 19

Antianginal Drugs (1):

Answer 19

Tx: Angina Pectoris

-Plaque builds up in lumens of blood vessels  atherosclerosis

Question 20

Antianginal Drugs (2):

Answer 20

Coronary arteries become narrower:
-Less blood flow to heart muscle

-Ischemia = angina pectoris / chest pain

Question 21

Antianginal Drugs – 3 types:

Answer 21

Nitrates
Beta-blockers
Calcium channel blockers

Question 22

Nitrates:

Answer 22

nitroglycerin (NTG):

-Most important drug in symptomatic relief of angina

Question 23

nitroglycerin (NTG):

Answer 23

SL:

1. ) Most common route
2. ) Rapid, predictable action
3. ) Onset 1-3 min
4. ) For acute anginal attack

Question 24

Nitroglycerin (1):

Answer 24

Ointment:

• Applied over 6x6 inch area of skin
• Cover with plastic wrap

Question 25

Nitroglycerin (2):

Answer 25

NTG transdermal patch:

1. ) Rotate sites
2. ) Worn 12-14 hrs/day
   3. ) “patch-off” period of 8-12 hrs 
   - Helps prevent tolerance

Question 26

NTG - Side Effects:

Answer 26

HA – most common:
-Acetaminophen for relief

Hypotension, dizziness, weakness

Taper off transdermal patch:
-Prevent rebound effect

Question 27

NTG - Nursing Process:

Answer 27

• ID card
• Avoid tobacco

Sublingual NTG:
-1st sign of attack

Question 28

Teach – NTG (1):

Answer 28

Take SL NTG if chest pain occurs:

-If pain is not better or has worsened 5 minutes after first dose –> CALL 911

Question 29

Teach — NTG (2):

Answer 29

Sit or lie down when taking NTG products for 1st time
-Hypotension

Fresh supply of SL NTG tabs every 3 mos (keep in original container)
-Store away from heat

Question 30

Nursing Process (2) — NTG:

Answer 30

1. ) Avoid direct contact with topical preparations
2. ) Rotate patch sites
3. ) Avoid:
   
   • Where defribillator paddles may be placed
   • Hairy areas

Question 31

Nursing Process (3) — NTG:

Answer 31

4. ) IV NTG only adm in glass bottles

5. ) Do not mix NTG with other drugs

Question 32

Selective Beta Blockers (cardiac):

Answer 32

atenolol (Tenormin):
-used to treat angina (chest pain) and hypertension (high blood pressure). It is also used to treat or prevent heart attack.

• Decrease HR & BP
• Avoids bronchoconstriction
• Drug group of choice for angina

Better for Resp. p/t

Question 33

Nursing Process — atenolol (Tenormin):

Answer 33

Monitor vital signs closely in early stages of therapy

Taper off drug slowly to prevent rebound effect

Question 34

isosorbide dinitrate (Isordil):

Answer 34

1. ) SL
2. ) prevent angina / heart conditions
3. ) Class = nitrate
4. ) Sit down before using this medication.
5. ) Use it 15 minutes before physical activity.

Question 35

nifedipine (Procardia):

Answer 35

1. ) prevent certain types of chest pain (angina)
2. ) calcium channel blockers
3. ) works by relaxing blood vessels so blood can flow more easily.
4. ) must be taken regularly to be effective

Question 36

nifedipine (Procardia):

Answer 36

5. ) po
6. ) x3 day w/ or w/o food
7. ) avoid grapefruit

Question 37

Class IV (Calcium Channel Blocker):

Answer 37

verapamil (Calan):

1. ) Blocks calcium influx –> decreases excitability & contractility
2. ) Tx: dysrhythmias, angina, & hypertension

Question 38

Nursing Dx — verapamil (Calan):

Answer 38

1. ) Decreased cardiac output r/t cardiac dysrhythmia
2. ) Anxiety r/t irregular heartbeat
3. ) Risk for activity intolerance r/t lack of oxygen secondary to irregular heart rate

Question 39

Nursing Interventions –verapamil (Calan):

Answer 39

Monitor:

• Vital signs (decreased BP)
• ECG for abnormal patterns

Question 40

Teach — verapamil (Calan):

Answer 40

Avoid:

• Alcohol
• Caffeine
• Tobacco

Question 41

(class 1) Sodium Channel Blockers

Answer 41

lidocaine (Xylocaine):

-Acute ventricular dysrhythmia

Question 42

lidocaine (Xylocaine):

Answer 42

SE (high doses):
-Bradycardia, hypotension

SE (less serious):
-Dizziness, light-headedness

Local anesthetic activity

Question 43

lidocaine (Xylocaine) CONT…..

Answer 43

Be sure client is not sensitive or allergic to similar local anesthetics