Digoxin Flashcards
1
Q
MOA of Digoxin
A
- (+) Inotropic: Increase myocardial contractility. Inhibits membrane bound Na/K APTase. Increase Ca+ in sarcoplasmic reticulum => increase contractility
- (-) chronotropic: AV Blocker: slows conduction through AV node
2
Q
Digoxin
- Brand name:
A
- Lanoxin
- Lanoxicaps
- Digitek
3
Q
Half life
A
38-48H
4
Q
Check dig MD level in how many days?
A
5-7 days
5
Q
Dosage Form:
- Yellow:
- White:
- Elixir:
A
- Yellow: 0.125mg
- White: 0.25mg
- Elixir: 0.5 or 0.05mg/mL. Protect Elixir from light
6
Q
Dose for SHF/Rate Control of chronic afib
A
- < 70 y.o: 0.25mg PO QD
- > 70 y.o/renal impairment: 0.125mg PO QD
7
Q
Dose for rapid a.fib
A
- LD: 1st dose 0.5mg IV. 2nd & 3rd dose: 0.25mg IV Q6
- MD: 0.125mg - 0.375mg IV/PO QD
8
Q
Additive bradycardia w/ other AV blockers and digoxin
A
ABC:
- Amiodarone
- BB: propafenone & Sotalol
- CCB: Verapamil & Diltiazem
9
Q
Drugs that increase Digoxin [ ]
A
- Quinidine: displace digoxin => reduce dose by 33-50%
- Amiodarone: reduce dose by 50%
- Verapamil: displace digoxin.
- Clarithromycin
10
Q
Risk of Dig Toxicity with meds decrease K
A
- Corticosteroids
- Thiazides & loops
- Amphotericin B
- Natural licorice
11
Q
Risk factors for Digoxin Toxicity
A
- Hypokalemia: diuretics, ampho B, lexatives
- Hypomagnesemia
- Hypercalemia: Ca+, Diuretic, Estrogen
- Med that interact with digoxin excretion: Verapamil, amiodarone, quinidine
- Decrease renal fxn
12
Q
Symptoms of Digoxin Toxicity
A
- Anorexia, *N/V, diarreha
- Somnolence & muscle weakness
- Yellow vision (Xanthopsia)
13
Q
Management of Digoxin Toxicity
A
- Stop Digoxin
- Correct HypoK
- Treat arrhythmia if present
- Digibind: Digoxin-immune Fab
- Digifab: powders are in refrigerator
14
Q
Digibind
A
Digoxin immune fab
38mg/vial
15
Q
Digifab
A
- 40mg/vial
- Powders are in refrigerator
- Use reconstitute w/ NS ASAP (stable only 4H). Use 0.22 micron filters to remove any protein aggregates that may present after reconstitution
- 1 vial binds to ~ 0.5mg digoxin
