Tolterodine, also known as PNU-200583E, s an antimuscarinic drug that is used for symptomatic treatment of urinary incontinence. Tolterodine acts on M2 and M3 subtypes of muscarinic receptors whereas older antimuscarinic treatments for overactive bladder act more specifically on M3 receptors. Tolterodine, although it acts on all types of receptors, has fewer side effects than oxybutynin (M3 and M1 selective, but more so in the parotid than in the bladder) as tolterodine targets the bladder more than other areas of the body.