Inhaled long-acting muscarinic antagonists in chronic obstructive pulmonary disease.

In 2002, the first long-acting muscarinic antagonist, tiotropium bromide (Spiriva(®)), was launched as a once-daily bronchodilating agent for the treatment of chronic obstructive pulmonary disease. Since then, there has been intense discovery research activity in this area and, currently, several alternative inhaled long-acting muscarinic antagonists are reported under clinical development by several pharmaceutical companies. This article will review the current inhaled development candidates, as well as literature reports of the most significant preclinical chemical series specifically designed as inhaled antimuscarinic agents.