What is the primary indication for the use of bethanechol?

Bethanechol is primarily indicated for the treatment of urinary retention, particularly in patients who have difficulty urinating due to postpartum or post-surgical conditions or in those with neurogenic bladders. It works as a muscarinic cholinergic agonist, stimulating the bladder's detrusor muscle, which enhances bladder contraction and promotes urination.

Its mechanism of action involves mimicking the effects of acetylcholine on muscarinic receptors in the bladder, which leads to increased tone and contraction of the bladder. This agent is particularly useful when there is a need to facilitate urination in cases of urinary retention rather than just providing symptomatic pain relief, managing blood pressure, or inducing muscle relaxation.