Oxybutynin

Oxybutynin is an anticholinergic and antispasmodic agent used to treat overactive bladder (OAB) and urinary urgency or incontinence. It works by blocking muscarinic M3 receptors on the detrusor muscle of the bladder, reducing involuntary detrusor contractions and increasing bladder capacity. This parasympathetic blockade decreases the urge to void and reduces episodes of urge incontinence. The same mechanism explains the adverse effects. Muscarinic receptors also support salivation, gastrointestinal motility, accommodation of near vision, sweating, and some central nervous system functions. Blocking them can therefore produce dry mouth, constipation, blurred vision, reduced sweating, confusion, or other cognitive changes. The drug calms an overactive bladder, but it does not eradicate a urinary infection or relieve a mechanical obstruction. Oxybutynin is used when behavioural treatment alone has not adequately controlled OAB symptoms. Behavioural measures may include bladder training, timed voiding, and strategies tailored to the patient’s fluid and urgency pattern. New dysuria, fever, haematuria, or systemic illness should prompt assessment for another cause rather than an automatic increase in oxybutynin.