Ramatroban

Ramatroban is a dual TP and DP₂/CRTH₂ receptor antagonist (K_is = 4.5 and 4.3 nM for the human receptors, respectively).¹ It is selective for these receptors over the prostaglandin E₂ (PGE₂) receptor subtypes EP₁ and EP₂, as well as the FP and IP receptors, at 1 µM.² Ramatroban inhibits contractions induced by U-46619 (Item No. 16450) or PGD₂ (Item No. 12010) in isolated guinea pig tracheal rings (pA₂s = 8.7 and 8.6, respectively). It also reduces PGD₂-induced migration of isolated human eosinophils when used at concentrations of 1, 10, and 100 nM.³ Ramatroban (5 mg/kg) inhibits ovalbumin-induced airway eosinophil infiltration and mucus cell hyperplasia in an ovalbumin-sensitized mouse model of asthma.⁴ Formulations containing ramatroban have been used in the treatment of allergic rhinitis.

WARNING This product is not for human or veterinary use.

1. Ulven, T., and Kostenis, E. Minor structural modifications convert the dual TP/CRTH2 antagonist ramatroban into a highly selective and potent CRTH2 antagonist. J. Med. Chem. 48(4), 897-900 (2005).

2. McKenniff, M.G., Norman, P., Cuthbert, N.J., et al. BAY u3405, a potent and selective thromboxane A₂ receptor antagonist on airway smooth muscle in vitro. Br. J. Pharmacol. 104(3), 585-590 (1991).

3. Sugimoto, H., Shichijo, M., Iino, T., et al. An orally bioavailable small molecule antagonist of CRTH2, Ramatroban (BAY u3405), inhibits prostaglandin D₂-induced eosinophil migration in vitro. J. Pharmacol. Exp. Ther. 305(1), 347-352 (2003).

4. Uller, L., Mathiesen, J.M., Alenmyr, L., et al. Antagonism of the prostaglandin D₂ receptor CRTH2 attenuates asthma pathology in mouse eosinophilic airway inflammation. Respir. Res. 8(1), 16 (2007).