In digoxin induced life-threatening ventricular dysrhythmia what pharmacotherapy, other than Fab, should be implemented?
Date First Published:
February 24, 2008
Last Updated:
February 24, 2008
Report by:
Leif Meyers, EM resident (GRMERC)
Three-Part Question:
In [patients with digoxin induced life-threatening ventricular dysrhythmias] is [magnesium or lidocaine or phenytoin] superior in [suppressing dysrhythmias or inproving mortality]
Clinical Scenario:
A 65 y.o. presents tachycardic, hypotensive and decreased LOC. ECG reveals ventricular tachycardia. As your staff places the pads for cardioeversion you discover he has been on digoxin for the past three years. You remember Digoxin Fab fragment, not cardioversion, is the treatment for digoxin induced ventricular dysrhythmias; however, you wonder if there are other therapies that maybe beneficial to your patient.
Search Strategy:
medline using OVID interface
Search Details:
(digoxin and toxicity and (dysrhythmia or arrhythmia or ventricular) and (magnesium or lidocaine or phenytoin or amiodarone)).mp.
Outcome:
matched 35 papers, of which 3 were relevent
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Magnesium sulfate in the treatment of ventricular arrhythmias due to digoxin toxicity. Kinlay S, Buckley NA 1995 Austrelia | A patient with digoxin toxicity, ventricular tachycardia and slightly elevated serum magnesium | Case report | conversion to a stable junctional rhythem with magnesium infusion | case report | |
| Massive digoxin overdose: successful treatment with intravenous amiodarone. R Maheswaran, M G Bramble, and C A Hardisty 1983 August 6 UK | A patient in ventricular fibrillation following a large digoxin ingestion. | Case Report | failed to convert with electrical cardioversion | case control. Large acute ingestion | |
| failed to convert with sodium bicarbonate | |||||
| failed to convert with lidocaine | |||||
| Successfully converted to a stable rhythem with amiodarone | |||||
| Magnesium therapy in massive digoxin intoxication French JH 1984, July USA | A patient with large acute digoxin ingestion in ventricular fibrillation | case control | failed to convert with lidocaine | case control | |
| failed to convert with phenytoin | |||||
| Converted to stable rhythem following magnesium | |||||
| Hypomagnesemia in relation to digoxin intoxication in children. Singh RB, Dube KP, Srivastav PK. Aug-76 USA | 19 children with heart failure on digoxin therapy. 3 of whom developed dysrhythmia | observational | magnesium successfully treated all dysrhythmias | observational. Children |
Author Commentary:
Digoxin toxicity can result in any dysrhythmia as a result of its suppressant and excitatory effects. Most concerning are ventricular dysrhythmias. Digoxin Fab antibody fragments are the treatment of choice for life-threatening dysrhythmias; however, when Digoxin Fab fragments are not immediately available temporizing therapies maybe necessary. Phenytoin and Lidocaine are thought to depress ventricular automaticity. Magnesium is thought to decrease ventricular irritability by competing with digoxin at the Na+K+ATPase.
Bottom Line:
Magnesium, phenytoin, and lidocaine are acceptable temporizing therapies in life-threatening, digoxin induced ventricular dysrhythmias. There is insufficient evidence to promote one therapy over another. Amiodarone maybe considered in dysrhythmias refractory to the above therapies.
References:
- Kinlay S, Buckley NA. Magnesium sulfate in the treatment of ventricular arrhythmias due to digoxin toxicity.
- R Maheswaran, M G Bramble, and C A Hardisty. Massive digoxin overdose: successful treatment with intravenous amiodarone.
- French JH. Magnesium therapy in massive digoxin intoxication
- Singh RB, Dube KP, Srivastav PK.. Hypomagnesemia in relation to digoxin intoxication in children.