When Bethanechol is administered, its main effect is to:

Bethanechol is a cholinergic agonist that primarily stimulates muscarinic receptors in the detrusor muscle of the bladder. When Bethanechol is administered, its main effect is to induce contraction of the bladder's detrusor muscle. This contraction helps to increase bladder pressure and facilitate voiding, making it a useful medication for conditions associated with urinary retention. The stimulation of the detrusor muscle promotes urination by helping to empty the bladder efficiently.

This mechanism is particularly beneficial in patients who have difficulty urinating due to conditions such as neuropathic bladder or after certain surgeries that might result in urinary retention. By favoring the contraction of the detrusor muscle, Bethanechol effectively helps to overcome the issue of urinary retention.