Fesoterodine is a prodrug. It is broken down into its active metabolite, 5-hydroxymethyl tolterodine, by plasma esterases.
Efficacy
Fesoterodine has the advantage of allowing more flexible dosage than other muscarinic antagonists. Its tolerability and side effects are similar to other muscarinic antagonists and as a new drug seems unlikely to make great changes in practices of treatment for overactive bladder.