盐酸奥洛他定（英语：Olopatadine）由东京的协和发酵工业株式会社研制，具有广泛的药物作用，如组织胺H1受体拮抗剂作用，化学介质抑制作用，速激肽释放抑制作用和嗜酸粒细胞浸润抑制作用。适用于过敏性鼻炎、荨麻疹和皮肤病引起的痒。在协和发酵工业株式会社的授权下，爱尔康制药研制了盐酸奥洛他定眼药水，药物商品名为帕坦洛（Patanol），无色至微黄色澄明液体，是一种选择性H1组胺受体拮抗剂和肥大细胞稳定剂,用于治疗过敏性结膜炎也称眼部过敏。每毫升帕坦洛含1.11mg盐酸奥洛他定（相当于1mg奥洛他定）。

Olopatadine hydrochloride is an antihistamine (as well as anticholinergic and mast cell stabilizer), sold as a prescription eye drop manufactured by Alcon in one of three strengths: 0.7% solution or Pazeo in the US, 0.2% solution or Pataday (also called Patanol S in some countries), and 0.1% or Patanol (also called Opatanol in some countries). It is used to treat itching associated with allergic conjunctivitis (eye allergies). A decongestant nasal spray formulation is sold as Patanase, which was approved by the FDA on April 15, 2008. It is also available as an oral tablet in Japan under the tradename Allelock, manufactured by Kyowa Hakko Kogyo.