H1 antihistamines: patent highlights 2000 – 2005

Abstract

Since the introduction of the first H1 antihistamine in 1945, much progress has been made in eliminating troublesome side effects. Early efforts were directed at improving selectivity and avoiding sedative properties, and later at preventing the non-mechanism-related cardiotoxicity observed in some of the second-generation H1 antihistamines. As the H1 antihistamines are still the first choice therapy against allergy symptoms, there remains an opportunity to obtain compounds with an improved and differentiated pharmacological and therapeutic profile. A patent literature review comprising the years 2000 – 2005 shows a reduction in the number of new chemical entities as H1 antihistamines and a growing interest in dual H1-X compounds. With the introduction of dual H1-H3 and H1-CCR3 antagonists, a new direction of research has emerged that offers the potential of discovering a superior H1 antihistamine with anti-inflammatory properties able to deal with the inflammation and nasal congestion associated with allergic diseases.