Nitroglycerin for Urinary Retention
Nitroglycerin is not effective for treating urinary retention and should not be used for this indication. The available evidence does not support any role for nitroglycerin in managing urinary retention, and it may actually worsen the condition through its hypotensive effects.
Why Nitroglycerin Is Not Indicated
No evidence base exists: None of the cardiovascular guidelines or research studies addressing nitroglycerin mention urinary retention as a treatment indication 1, 2.
Mechanism of action is counterproductive: Nitroglycerin acts primarily as a venodilator that lowers preload and reduces blood pressure 1, 2. This vasodilatory effect does not address the pathophysiology of urinary retention, which involves bladder outlet obstruction or detrusor muscle dysfunction 3, 4.
Risk of adverse effects: Nitroglycerin causes orthostatic hypotension, which is particularly problematic in elderly patients who are at highest risk for urinary retention 1. This could complicate management and potentially worsen patient outcomes.
Established Treatments for Urinary Retention
The evidence-based approach to acute urinary retention involves:
Immediate bladder catheterization for symptomatic relief, which is the standard of care for acute urinary retention 3, 4.
Alpha-blockers (such as doxazosin) may be considered in patients with benign prostatic hyperplasia, though evidence shows only modest benefit with 31-33% maintaining spontaneous micturition after catheter removal 5.
Cholinergic agents combined with sedatives showed some promise in post-operative urinary retention (RR 1.39,95% CI 1.07-1.82), though evidence quality is limited 6.
Intravesical prostaglandin demonstrated statistically significant benefit for post-operative retention (RR 3.07,95% CI 1.22-7.72) 6.
Common Pitfalls to Avoid
Do not confuse cardiovascular indications with urologic conditions: Nitroglycerin's role in acute heart failure, cocaine-associated chest pain, and hypertensive emergencies 1 has no relevance to urinary retention management.
Recognize drug-induced urinary retention: Up to 10% of urinary retention episodes are medication-related, commonly from anticholinergics, opioids, alpha-agonists, and calcium channel blockers 3. The treatment is discontinuation of the offending agent, not addition of nitroglycerin.
Address the underlying cause: Urinary retention requires identification of the etiology (benign prostatic hyperplasia, neurogenic bladder, medication effect, post-operative state) and targeted treatment 3, 4.