Trospium chloride: over 20 years of clinical use

10.1586/14750708.3.2.215 © 2 Antimuscarinic drugs currently form the mainstay of pharmacotherapy for overactive bladder. Trospium chloride, an antimuscarinic with an unusual quaternary amine structure, has recently gained approval in the USA for the treatment of this condition. As a quaternary amine, trospium has pharmacological properties that are distinct from other available antimuscarinics and which contribute to its salutary safety and efficacy profile. Limited ability to cross the blood–brain barrier minimizes the potential for centrally mediated adverse events. Metabolism independent of the cytochrome P450 isoenzyme system allows confident prescription of trospium alongside the majority of commonly used drugs. The presence of unchanged trospium in the bladder – the primary therapeutic site of action – may contribute to pharmacological activity, providing earlier onset and improved and prolonged efficacy compared with other, more extensively metabolized antimuscarinic agents.