Inhaled
anticholinergics (
ipratropium bromide and
tiotropium bromide) are widely used as maintenance treatment in
chronic obstructive pulmonary disease. Previous studies have reported on their cardiovascular effects but relatively little is known about their effects on the bladder. Acute
urinary retention is a medical emergency which can be associated with serious complications. Our objective was to evaluate the existing literature regarding the effects of inhaled
anticholinergics on
urinary retention among patients with
chronic obstructive pulmonary disease. We searched PubMed and the United States Food and Drug Administration (FDA) adverse events database for case reports, observational studies, randomized controlled trials (or meta-analyses of such trials) that reported on the outcome of
urinary retention with inhaled
anticholinergics (
ipratropium or
tiotropium). We checked 27 published articles and identified relevant papers including two case reports, three pooled analyses, two observational studies and one randomized controlled trial. Two of the observational studies and a pooled analysis of randomized controlled trials reported a significant increase in the risk of acute
urinary retention with inhaled
anticholinergics. Older patients with
benign prostatic hyperplasia seem to be at the highest risk of this adverse effect which tends to occur soon
after treatment initiation. Although all the links in the chain have yet to be fully elucidated, the preponderance of evidence suggests the possibility of a causal relationship between inhaled
anticholinergics and
urinary retention. Clinicians should carefully balance these and other adverse effects of inhaled
anticholinergics against their known symptomatic benefits on exacerbations, after eliciting patient preferences for various outcomes in a shared decision-making context.