Ch. 42 - Cardiac Glycosides Flashcards Preview

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Flashcards in Ch. 42 - Cardiac Glycosides Deck (43)
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1
Q

Drugs Affect Cardiac Function By:

A

Inotropic = contraction

Chronotropic = heart rate

Dromotropic = electrical impulses

2
Q

Cardiac Glycosides (1):

A

Digoxin & similar drugs:
-Foxglove plant (digitalis)

Mainly used to treat CHF

3
Q

Cardiac Glycosides (2):

A

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

2.) Increase mechanical efficiency size of heart decreases
4
Q

Cardiac Glycosides (3):

A

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

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

Cardiac Glycosides (4):

A

Negative chronotropic action:
-Slows heart rate

Tx: CHF, arrhythmias

6
Q

Selecting Appropriate Drug:

A

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

Stay with same brand

7
Q

Two main drugs:

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

DON’T CONFUSE THE TWO!

8
Q

digoxin (Lanoxin):

A
  • Antiarrhythmic and blood pressure support

- It can treat heart failure and heart rhythm problems.

9
Q

digoxin (Lanoxin) – Dosage:

A

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

Maintenance:
- Po: 0.125 – 0.5 mg/day

10
Q

digoxin (Lanoxin) — Monitoring:

A

Low therapeutic index
- Monitor clients!

Therapeutic blood levels:
- 0.8 – 2 ng/mL

11
Q

digoxin (Lanoxin) — S/S Drug Toxicity:

A

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

Neurological effects:
-Visual disturbances, Restless, HA

Cardiac effects

12
Q

Predisposing Factors to Toxicity:

A

Hypokalemia
Renal impairment
IV drug administration

13
Q

digoxin — Antidote for Severe Intoxication:

A

Digoxin immune fab:

- Binds with digoxin
- Forms complex molecules 
- Excreted in urine
14
Q

Nursing Process (1) — digoxin:

A

Check apical pulse for 1 min before adm:

-Do NOT adm if pulse rate

15
Q

Nursing Process (2) — digoxin:

A

Monitor serum digoxin level:

  • Normal range = 0.8 – 2 ng/ml
  • Toxic = > 2 ng/ml
16
Q

Nursing Process (3) — digoxin:

A

If toxicity suspected –> anticipate serum drug levels

Antidote:
-Digoxin Immune Fab

17
Q

Nursing Process (4) — digoxin:

A

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

Report hypokalemia

18
Q

Teaching (3) — digoxin:

A

Diet:

-Encourage foods high in potassium

19
Q

Antianginal Drugs (1):

A

Tx: Angina Pectoris

-Plaque builds up in lumens of blood vessels  atherosclerosis

20
Q

Antianginal Drugs (2):

A

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

-Ischemia = angina pectoris / chest pain
21
Q

Antianginal Drugs – 3 types:

A

Nitrates
Beta-blockers
Calcium channel blockers

22
Q

Nitrates:

A

nitroglycerin (NTG):

-Most important drug in symptomatic relief of angina

23
Q

nitroglycerin (NTG):

A

SL:

  1. ) Most common route
  2. ) Rapid, predictable action
  3. ) Onset 1-3 min
  4. ) For acute anginal attack
24
Q

Nitroglycerin (1):

A

Ointment:

  • Applied over 6x6 inch area of skin
  • Cover with plastic wrap
25
Q

Nitroglycerin (2):

A

NTG transdermal patch:

  1. ) Rotate sites
  2. ) Worn 12-14 hrs/day
    3. ) “patch-off” period of 8-12 hrs 
    - Helps prevent tolerance
26
Q

NTG - Side Effects:

A

HA – most common:
-Acetaminophen for relief

Hypotension, dizziness, weakness

Taper off transdermal patch:
-Prevent rebound effect

27
Q

NTG - Nursing Process:

A
  • ID card
  • Avoid tobacco

Sublingual NTG:
-1st sign of attack

28
Q

Teach – NTG (1):

A

Take SL NTG if chest pain occurs:

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

29
Q

Teach — NTG (2):

A

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

30
Q

Nursing Process (2) — NTG:

A
  1. ) Avoid direct contact with topical preparations
  2. ) Rotate patch sites
  3. ) Avoid:
    • Where defribillator paddles may be placed
    • Hairy areas
31
Q

Nursing Process (3) — NTG:

A
  1. ) IV NTG only adm in glass bottles

5. ) Do not mix NTG with other drugs

32
Q

Selective Beta Blockers (cardiac):

A

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

33
Q

Nursing Process — atenolol (Tenormin):

A

Monitor vital signs closely in early stages of therapy

Taper off drug slowly to prevent rebound effect

34
Q

isosorbide dinitrate (Isordil):

A
  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.
35
Q

nifedipine (Procardia):

A
  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
36
Q

nifedipine (Procardia):

A
  1. ) po
  2. ) x3 day w/ or w/o food
  3. ) avoid grapefruit
37
Q

Class IV (Calcium Channel Blocker):

A

verapamil (Calan):

  1. ) Blocks calcium influx –> decreases excitability & contractility
  2. ) Tx: dysrhythmias, angina, & hypertension
38
Q

Nursing Dx — verapamil (Calan):

A
  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
39
Q

Nursing Interventions –verapamil (Calan):

A

Monitor:

  • Vital signs (decreased BP)
  • ECG for abnormal patterns
40
Q

Teach — verapamil (Calan):

A

Avoid:

  • Alcohol
  • Caffeine
  • Tobacco
41
Q

(class 1) Sodium Channel Blockers

A

lidocaine (Xylocaine):

-Acute ventricular dysrhythmia

42
Q

lidocaine (Xylocaine):

A

SE (high doses):
-Bradycardia, hypotension

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

Local anesthetic activity

43
Q

lidocaine (Xylocaine) CONT…..

A

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