Rolapitant (INN,[2] trade name Varubi /vəˈruːbi/ və-ROO-bee in the US and Varuby in the European Union) is a drug originally developed by Schering-Plough and licensed for clinical development by Tesaro, which acts as a selective NK1 receptor antagonist (antagonist for the NK1 receptor).

[1] Under the European approval, it is contraindicated in combination with St. John's Wort, which is expected to accelerate inactivation of rolapitant.

Common side effects included decreased appetite (9% under rolapitant vs. 7% under placebo), neutropenia (9% vs. 8% or 7% vs. 6%, depending on the kind of chemotherapy), dizziness (6% vs. 4%), indigestion and stomatitis (both 4% vs.

[8] Strong inducers of the liver enzyme CYP3A4 decrease the area under the curve of rolapitant and its active metabolite (called M19); for rifampicin, this effect was almost 90% in a study.

[8] The drug is used in form of rolapitant hydrochloride monohydrate, a white to off-white, slightly hygroscopic crystalline powder.