Fosaprepitant dimeglumine (MK-0517 or L-785,298), an intravenous neurokinin-1 antagonist for the prevention of chemotherapy induced nausea and vomiting.

Background: This paper reviews the existing literature on fosaprepitant, an intravenous neurokinin-1 anatgonist for the prevention of chemotherapy induced nausea and vomiting.

Objectives: To describe the development of fosaprepitant and to situate the intravenous form of aprepitant in the current market of available antiemetics.

Methods: Literature was screened and selected in order to compare the intravenous form of the already commonly used NK-1 receptor antagonist aprepitant.

Results: Aprepitant is the first and still the only marketed neurokinin-1 (NK-1) antagonist. Interestingly, the first studies were performed with fosaprepitant dimeglumine (MK-0517 or L-785,298), the water-soluble prodrug of aprepitant. Fosaprepitant is converted into aprepitant within 30 min after intravenous administration. Based on equivalence studies, 115 mg fosaprepitant seems to be the substitute for 125 mg orally administrated aprepitant. Tolerability of the prodrug is no different from the active drug. The number of efficacy studies with fosaprepitant is very limited and most data are derived from existing aprepitant results. Fosaprepitant has recently been approved by FDA and EMEA as an intravenous substitute for oral aprepitant on day 1 of the standard 3-day CINV prevention regimen, which also includes dexamethasone and a 5-HT3 antagonist.