Inhaled Drugs for COPD Linked to Urinary Problem
Study Shows Inhaled Anticholinergic Drugs May Increase Risk for Acute Urinary Retention
May 23, 2011 -- Men who take certain kinds of inhaled medications to treat chronic lung disease are more likely to experience a medical emergency called acute urinary retention than those who don't take the drugs, a new study shows.
Acute urinary retention is feeling the pressure, pain, and urgency of a having full bladder without being able to relieve it by urination. If left untreated, urine can back up into the kidneys, causing infections and even organ damage.
The study, of more than a half million older adults with chronic obstructive pulmonary disease (COPD), found that men taking inhaled anticholinergic medications, which are sold under the brand names Atrovent, Combivent, and Spiriva, had about a 40% higher risk of acute urinary retention compared to those who were not taking these kinds of medications.
"The thing is that often people don't associate [the inhaled drugs] with a problem peeing," says study researcher Anne Stephenson, MD, MPH, a pulmonologist at St. Michael's Hospital in Toronto. "Not only does the patient not necessarily make that connection, but I think clinicians don't make the connection because there's a belief, not necessarily rightly, that the drugs aren't systemically absorbed."
The risk was higher in men who had just started on the drugs, those who had enlarged prostates, and those using both short- and long-acting anticholinergic bronchodilators at the same time.
There was no increased risk of urinary retention observed in women.
The study is published in the Archives of Internal Medicine.
"It's impressive," says Elizabeth Kavaler, MD, a urologist at Lenox Hill Hospital in New York City who was not involved in the study. "I thought it was a really well done, complicated study. And it certainly reminds us to be attentive in these situations and for patients to be attentive."
Experts, including the study's authors, are careful to note that the study was only able to show an association between the drugs and the risk of urinary retention but that it couldn't prove that the drugs caused the problem.
However, the fact that the increased risk was seen in those who were newly treated and those on more than one kind of anticholinergic medication makes for a strong case.
"The whole thing makes sense," Kavaler says. "Activation of acetylcholine helps you urinate, so if you block that, it relaxes the bladder. So it makes your bladder lazy."
Companies that manufacture anticholinergic inhalers say the risk of urinary retention associated with anticholinergic drugs is known.
"It does not add clinical information that would at all change the risk-benefit profile of Spiriva," says Emily Baier, a spokeswoman for Boehringer Ingelheim, the company that makes Spiriva.
"Urinary retention is a known side effect of anticholinergics and can occur in particular with patients with conditions like BPH [benign prostatic hypertrophy]. This is actually listed in our label," Baier says.