What common drugs may exacerbate urinary retention in my patient with spinal cord injury?

Anticholinergics (including tricyclic antidepressants-TCAs), selective serotonin reuptake inhibitors (SSRIs), benzodiazepines, opioids, alpha-adrenergics, and non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common agents associated with urinary retention1.  This adverse reaction is particularly observed in patients with pre-existing hypoactive bladder, including those with spinal cord injury (SCI).  Unfortunately, patients with SCI also often require pharmacologic management of neuropathic pain with one or more of these agents (eg, TCAs, opioids, and NSAIDs).

The mechanism of urinary retention may vary depending on the agent. Anticholinergics (eg, TCAs, diphenhydramine) decrease detrusor muscle contraction via blockade of the parasympathetic pathway.1 Opiates may increase the sphincter tone of bladder via sympathetic stimulation, as well as decrease the sensation of bladder fullness by partial inhibition of the parasympathetic nerves that innervate the bladder.2 SSRIs increase external sphincter tone by inhibiting serotonin reuptake.3 Alpha-adrenergics (e.g. ephedrine) can lead to detrusor relaxation and sphincter contraction.3 NSAIDs are thought to inhibit prostaglandin-mediated detrusor contraction.5

Although most patients with SCI have urinary incontinence due to detrusor hyperactivity, some will have urinary retention due to detrusor hyporeflexia.6

Final Fun Fact: Did you know that medications may account for up to 10% of urinary retention episodes? 



  1. Verhamme KM, Sturkenboom MC, Stricker BH, Bosch R. Drug-induced urinary retention. Drug Saf 2008;31(5):373-88. https://www.ncbi.nlm.nih.gov/pubmed/18422378
  2. Elsamra SE, Ellsworth P. Effects of analgesic and anesthetic medications on lower urinary tract function. Urologic Nursing 2012;32: 60-68. https://www.suna.org/download/education/2014/article320260067.pdf
  3. Thor KB. Serotonin and norepinephrine involvement in efferent pathways to the urethral rhabdosphincter: implications for treating stress urinary incontinence. Urology 2003; 62:3-9. https://www.ncbi.nlm.nih.gov/pubmed/14550831
  4. Glidden RS, DiBona FJ. Urinary retention associated with ephedrine. J Pediatr 1977; 90:1013-4. https://www.ncbi.nlm.nih.gov/pubmed/859049
  5. Verhamme KM, Dieleman JP, Van Wijk MA, et al. Nonsteroidal anti-inflammatory drugs and increased risk of acute urinary retention. Arch Intern Med. 2005;165:1547–1551. https://www.ncbi.nlm.nih.gov/pubmed/16009872
  6. Fowler CJ, O’Malley KJ. Investigation and management of neurogenic bladder dysfunction. J Neurol Neurosurg Psychiatry 2003;74(Suppl IV):iv27–iv31. http://jnnp.bmj.com/content/jnnp/74/suppl_4/iv27.full.pdf


Contributed by Alice Choi, Medical Student, Harvard Medical School, Boston, MA.


What common drugs may exacerbate urinary retention in my patient with spinal cord injury?

What are the benefits and risks of inhaled dual anticholinergic therapy (IDAT) in patients admitted to the hospital with a diagnosis of acute exacerbation of chronic obstructive pulmonary disease (AECOPD)?

Patients admitted with AECOPD are commonly on maintenance tiotropium and are frequently treated with additional inhaled anticholinergic agents (eg, ipratropium) during hospitalization. However, the scientific evidence justifying IDAT in patients with AECOPD is lacking, and is quite limited even in patients with stable COPD1-3.   Two small, randomized double-blind studies compared the impact of tiotropium combined with either ipratropium or placebo in outpatients with stable COPD.  Both studies selected FEV1 alone as their primary end-point and found only a marginal benefit with IDAT2,3

A population-based study of acute urinary retention in persons with COPD aged ≥66 years found a significantly higher odds of acute urinary retention among those on IDAT vs monotherapy or no anticholinergics (odds ratios 1.4 and 2.7, respectively)4.

In short, routine use of IDAT in patients with AECOPD lacks firm evidence in its clinical efficacy and may be associated with acute urinary retention.

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  1. Cole JM, Sheehan AH, Jordan JK. Concomitant use of ipratropium and tiotropium in chronic obstructive pulmonary disease. Ann Pharmacother 2012;46:1717-21.
  2. Kerstjens HA, Bantje TA, Luursema PB, Sinninghe Damste HE, de Jong JW. Effects of short-acting bronchodilators added to maintenance tiotropium therapy. Chest 2007;132:1493-9.
  3. Cazzola M, Santus P, D’Adda A, et al. Acute effects of higher than standard doses of salbutamol and ipratropium on tiotropium-induced bronchodilation in patients with stable COPD. Pulm Pharmacol Ther 2009; 22:177-82.
  4. Singh S, Furbergt CD. Inhaled anticholinergic drug therapy and the risk of acute urinary retention in chronic obstructive pulmonary disease. Arch Intern Med 2011;171:920-2.


Contributed by Josh Ziperstein, MD, Massachusetts General Hospital, Boston.

What are the benefits and risks of inhaled dual anticholinergic therapy (IDAT) in patients admitted to the hospital with a diagnosis of acute exacerbation of chronic obstructive pulmonary disease (AECOPD)?