Toxicological Controversies Series
Molar Vs Semi-molar Digifab Neutralization for Digoxin Toxicity
June 2016| Saad Al-Juma
Digifab availability had definitely contributed significantly to reduce the mortality rate associated with Digoxin toxicity since its first used as antidote in 1976 by Smith and his colleagues.1-2 Although it has been about 4 decades since this modality of treatment has been applied and widely accepted, the in there is some differences in the recommended dosage of Digifab in acute digoxin toxicity.1 Moreover, the dramatic increase of its price recently had lead to the need to determine the necessary dose once indicated.3 The is some evidence that the traditional method of predicting the number of vials needed for Digifab based on ingested amount of digoxin or its serum concentration in the acute setting might potentially over-treat such patients. 4 Chronic digoxin toxicity has different presentation and can be influenced by many factors associated to the population of the patients of this condition (e.g. Renal impairment, age and drug interactions). This makes the standardized dosage of digifab among acute and chronic toxicity patient questionable.
The idea of semi-molar correction of digoxin level in digoxin toxicity was raised not very recently by many studies, given the fact of the unique features of digoxin, digifab and also the patients who usually present with this condition.
In this controversy, we aim to look into the current practice for these presentation to gain more understanding of this perspective and experience from the clinical point of view.
1.Chan BS, Buckly NA Digoxin-specific antibody fragments in the treatment of digoxin toxicity. Clin Toxicol (Phila). 2014 Sep-Oct;52(8):824-36. doi: 10.3109/15563650.2014.943907. Epub 2014 Aug 4.
2.Smith TW , Haber E , Yeatman L , Butler VP , Jr . Reversal of advanced digoxin intoxication with Fab fragments of digoxin-specifi c antibodies. N Engl J Med 1976 ; 294 : 797 – 800
3.Kirrane BM , Olmedo RE , Nelson LS , Mercurio-Zappala M , Howland MA , Hoffman RS . Inconsistent approach to the treatment of chronic digoxin toxicity in the United States . Hum Exp Toxicol 2009 ; 28 : 285 – 292 .
4.Eyer F , Steimer W , Muller C , Zilker T . Free and total digoxin in serum during treatment of acute digoxin poisoning with Fab fragments: case study . Am J Crit Care 2010 ; 19 : 391 – 387 .