Response to ‘Aprepitant and fosaprepitant decrease the effectiveness of hormonal contraceptives’

We thank Bailard and Rebello 1 for bringing attention to the clinical relevance of the interaction between aprepitant/fosaprepitant and ethinyl estradiol. Publications were included in our systematic review 2 if they (1) described changes in pharmacokinetic parameters of a drug given concomitantly with aprepitant or fosaprepitant or described an adverse event ascribed to a drug interaction with aprepitant or fosaprepitant; (2) described these events in humans; (3) reported primary data; and (4) were published in full‐text or, for meeting abstracts, were published in 2013 or later. Since a description of this interaction has not been formally published, we were unable to include it in our systematic review.

We are in agreement with Bailard and Rebello. The interaction between ethinyl estradiol and aprepitant/fosaprepitant is likely clinically significant and an important interaction to take into consideration in clinical practice. This example signals to researchers and pharmaceutical companies the importance of publishing drug interaction study data fully and openly using methods outlined in the United States Food and Drug Administration guidance document 3 for conducting drug interaction studies. Having the full details of drug‐drug interaction study findings openly available increases awareness of clinically significant interactions and enables healthcare providers to make informed clinical decisions.

Competing Interests

There are no competing interests to declare.

Patel, P. , Leeder, J. S. , Piquette‐Miller, M. , and Dupuis, L. L. (2018) Response to ‘Aprepitant and fosaprepitant decrease the effectiveness of hormonal contraceptives’. Br J Clin Pharmacol, 84: 604. doi: 10.1111/bcp.13487.