Ramatroban (INN) (also known as BAY u3405) is a thromboxane receptor antagonist. It is also a DP2 receptor antagonist. It is indicated for the treatment of coronary artery disease. It has also been used for the treatment of asthma. Ramatroban was developed by the German pharmaceutical company Bayer AG and is co-marketed in Japan by Bayer Yakuhin then marketed by Kyorin Pharmaceutical and Nippon Shinyaku Co., Ltd. under the trade name Baynas.