Weakness of the urinary sphincter or pelvic muscles (bladder outlet incompetence)

Alpha-adrenergic blockers (such as alfuzosin, doxazosin, prazosin, tamsulosin, or terazosin), which relax the urinary sphincter

Hormone therapy (usually estrogen/progestin combination therapy taken by mouth), which can contribute to thinning of the pelvic muscles and supporting tissues

Misoprostol, which relaxes the urinary sphincter

Underactivity of bladder wall muscles

Drugs with anticholinergic effects Anticholinergic: What Does It Mean? (such as antihistamines, antipsychotic drugs, benztropine, or tricyclic antidepressants), which inhibit bladder muscle contractions

Calcium channel blockers (such as diltiazem, nifedipine, or verapamil), which inhibit bladder muscle contractions

Opioids, which seem to inhibit bladder contractility