Propiverine ER Safe, Effective for Overactive Bladder

By Scott Baltic

NEW YORK (Reuters Health) - The extended-release formulation of propiverine is "an effective and well-tolerated treatment option" for patients with symptoms of overactive bladder (OAB), according to a new study.

In addition, the randomized, controlled, multicenter noninferiority trial found that propiverine ER 30 mg was at least as safe and effective as tolterodine ER 4 mg for treatment of patients with OAB. The study was the first head-to-head trial between these two drugs.

The study, by Chinese, German, and Austrian researchers, was reported online on May 13 in BJU International.

Given the near-equivalence of many OAB drugs, most of which are anti-cholinergic/anti-muscarinic agents, three urologists interviewed by Reuters Health discussed why a clinician might prescribe one such drug versus another.

To start with, Dr. Roger Dmochowski of Vanderbilt University Medical Center told Reuters Health in a phone interview that propiverine is not approved in the United States, only in Japan and parts of Europe.

Dr. Dmochowski, who by happenstance reviewed the recent study for BJUI, added that propiverine is not considered a pure anti-muscarinic, because it also affects calcium homeostasis (which the report also noted). Still, he added, in broad patient populations, the anti-cholinergic/anti-muscarinic agents are largely interchangeable.

Dr. Christopher Payne of Stanford University, who spoke with Reuters Health by phone, agrees that there's not much evidence, despite pharmaceutical company marketing campaigns, that any one of the anti-cholinergics stands out from the others. "Nobody has a compelling reason to change practice."

Selection of an OAB drug therefore revolves less around efficacy than around safety, such as central nervous system effects, like possible exacerbation of dementia, he added, but "proven differences in safety are hard to show."

In reality, Dr. Payne said, most physicians in the United States simply start with whatever is on the patient's insurer's formulary. Beyond that, "People will have their favorites."

"My interpretation of the European Association of Urology guidelines is that in their opinion there is no recognizable difference between drugs possessing anti-muscarinic properties" for treatment of OAB, Dr. Alan J. Wein, of the Perelman School of Medicine and University of Pennsylvania Health System, told Reuters Health by email. "Some are titratable, which in my opinion is an advantage."

"It's mostly a matter of personal preference based on any one individual's experience or what they think is their experience with a particular drug," Dr. Wein added.

"Some practitioners are impressed with what I call 'theoretical edges,' which have to do with the drug's receptor blockade characteristics or physico-chemical/absorption/distribution properties. Rarely, if ever, do these translate into real edges in my opinion," Dr. Wein concluded.

The recent study recruited 324 Chinese patients (244 women, mean age 50 years) with OAB symptoms, who were randomized to take one of the two drugs once daily. The primary endpoint was change in mean voiding frequency per 24 hours, after eight weeks of treatment.

Propiverine ER 30 mg was significantly more effective at this measure than was tolterodine ER 4 mg, reducing voiding frequency from 15.2 per 24 hours at baseline to 10.6 at eight weeks, versus a reduction from 14.7 to 10.9 in the tolterodine group (p=0.005).

Safety and tolerability of the two drugs were similar, though the discontinuation rate attributable to adverse events was greater under tolterodine ER (7.4%) than under propiverine ER (3.1%).

The corresponding author did not respond to a request for comment.

The study was sponsored by Lee's Pharmaceutical, Hong Kong, and supported with a grant from Apogepha Arzneimittel, Dresden, Germany, the developer of propiverine. One coauthor made a disclosure.

SOURCE: https://bit.ly/1rbJb6C

BJU Int 2016.

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