Q:  What is the 'rule of thumb' for giving Digoxin immune Fab (digibind, DigiFab) in patients with digoxin ingestion resulting in toxicity?


Answer:  Each vial of DigiFab  contains 40 mg of Fab and it binds 0.5 mg digoxin. As a 'rule of thumb'

• - in acute ingestion of unknown amount 10 vials are recommended, and if required 10 more vials can be administered.
• - in patients on chronic digoxin therapy, where toxicity is suspected -  6 vials should be sufficient to resolve symptoms.

Resolution can be best monitored by EKG changes. Resolution may be visible in 30 minutes but it takes 2-4 hours before full effect takes place. 

DigiFab is usually given in IV preparation over 30 minutes, but IV push can be given in life-threatening situations though it may cause some febrile reactions, otherwise it is considered to be a safe medicine. It should be avoided in patients with allergy to sheep protein and papaya extracts.