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.

Keywords::

• allergic disease
• CCR3 antagonist
• H1 antihistamine
• H1 histamine receptor
• H3 histamine receptor