Dabigatran could be an oral alternative to low-molecular weight heparin for VTE prophylaxis during the post-partum period, a proof of concept study suggests.  

The research team from Newcastle University in the UK noted that dabigatran etexilate, the pro-drug of the active agent dabigatran, was minimally absorbed from the gastro-intestinal tract and its physico-chemical properties indicated that its transfer into breast milk was likely to be limited.

The single-centre open label study involved two women who had given birth within the past week and had made the decision not to breastfeed. Following a single oral dose of dabigatran, venous blood and breast milk samples were collected at 0,1,2,3,5,7 and 10 hours post-dose.

The milk to plasma (M/P) ratio was calculated from the area under the milk and plasma concentration. The absolute infant dose (had the woman been breast feeding) was calculated from the average dabigatran concentration in breast milk (AUC0-t/t) and an average (range) milk intake after birth. 

 Results showed that milk/plasma (MP) AUC concentration was 0.02 and 0.1 for subject 1 and 2 respectively. 

“Drugs with an extremely low M/P values (e.g 0.1) are likely to be safe during breastfeeding (excluding those drugs contraindicated because of extreme toxicity),” the study authors wrote.

The estimated maximum plasma dabigatran concentrations in the neonate were 100,000 times below the concentrations that would have a significant effect on coagulation indices, the study authors wrote in their paper published in the American Journal of Hematology. 

“The results of this study indicate that dabigatran etexilate is a suitable candidate for further investigation as an oral agent for thromboprophylaxis in post-partum women,” they concluded. 

However, they conceded that the inclusion of two women was an important limitation of the study and further studies would need to extend breast milk sampling to 24 hours as the secretion of dabigatran into breast milk is delayed.