Methods, devices, and medicaments that include trospium are provided for use in the treatment of bladder dysfunction by locally administering the trospium into the bladder to achieve a sustained concentration of trospium in urine in the bladder sufficient to produce a therapeutic concentration of trospium in bladder tissue. The drug may be delivered into the bladder from an intravesical drug delivery device inserted into the bladder, wherein the device continuously releases the drug into the urine in the bladder over an extended period of hours or days.