Distinguishing between obstruction, an unstable bladder, and OAB is not so easy, physicians find
By Nelly Edmondson Gupta
Overactive bladder (OAB) is usually associated with women, but it afflicts nearly one out of every eight American men. Its symptoms can also be confused with those of BPH, resulting in unneeded surgery.
“Sometimes when a surgeon does a prostatectomy for BPH, in retrospect it turns out that the symptoms were due to an unstable bladder,” says Ryan Paterson, MD, assistant professor of urology at the University of British Columbia in Vancouver. “Post-surgery these patients may have a stronger urinary stream, but they may still be miserable—and angry at their doctors.”
Distinguishing between obstruction and OAB can be tricky because symptoms can overlap, notes David Staskin, MD, associate professor of urology at New York-Presbyterian Hospital/ WeillCornellMedicalCenter. “As a result, there is sometimes a lack of understanding about whether a patient's symptoms are the result of a primary bladder problem—with or without an identifiable cause—or are secondary to obstruction. If men are not obstructed,” he adds, “you can probably treat them the same way you'd treat women with OAB because the pathophysiology is the same.”
Dr. Paterson points out that OAB produces specific irritative symptoms, including urinary frequency, urgency, and nocturia, in the absence of significant pathology such as bladder tumors or bladder stones. “If a patient has a stroke and develops an unstable bladder, it's not OAB,” he says. Less frequent causes of lower urinary tract symptoms (LUTS) include infection, urethral stricture, advanced prostate cancer, and bladder stones.
Genders not so different?
Simon Hall, MD, chairman of the department of urology and director of the Deane Prostate Health and ResearchCenter at the Mount Sinai School of Medicine in New York, says it's not clear how OAB differs in men and women. “A lot of the symptoms that we ascribe to prostate problems in men may if fact be due to things that happen to women as well,” he explains. “For example, as we age, the bladder becomes stiffer and less elastic. In women there are post-menopausal changes, too, but there is commonality between the genders that we have not fully appreciated.”
Assess magnitude of symptoms
When a man presents with LUTS, Dr. Hall says he first tries to gauge how bothersome the problem is. “I ask whether he's had to make alterations in his lifestyle. Does he make it a point not to drink anything when he goes out? Does he carry a container in the car?” Dr. Hall also wants to rule out medical problems, such as bladder stones, bleeding, infection, urinary retention, and kidney problems. If none are present, he says, it's a lifestyle issue. “I then may tell patients that as long as their PSA levels are within normal range, it's unlikely that they'll get significantly worse. In such cases, some men will choose to defer treatment.”
Dr. Paterson says all patients should receive an AUA symptom score, which includes a quality-of-life index. The index can be found online at http://www.prostatecancer.org/tools%20/forms/aua_symptom_form.pdf. Some patients may have a relatively high symptom score but not be that bothered, while others can have low scores but be very bothered, he says.
“To some extent this has to do with a man's stage of life. A busy executive who has to urinate three times each night may be more bothered than a retiree. If a patient has BPH, the urologist could ask, ‘Can you live with the symptoms the way they are now?' If the answer is yes, active surveillance may be an appropriate strategy.”
Patients who want OAB symptom relief can be placed on an anticholinergic. “There are now five different pills and a patch,” notes Dr. Hall. “Patients who are already taking a lot of medication may prefer a patch. If patients are taking anticholinergics, though, you have to monitor them to be sure they aren't in retention.”
In the past, Dr. Hall continues, “it was considered a major faux pas to put the average man with urinary problems on meds to treat OAB. But some studies show you can treat men with OAB meds for mild-to-moderate LUTS, and that treating patients with PDE-5 [phosphodiesterase-5] inhibitors may improve urinary function.”
Following evaluation, most patients with obstructive symptoms are put on alpha blockers, which is the standard of care, says Dr. Hall. “If a patient has elevated PSA in addition to symptoms, but no evidence of cancer, it's reasonable to take this route. I generally put average patients with relatively small prostate glands (30 grams) on an al-pha blocker. If a patient has a prostate over 50 cc, putting him on a 5-alpha-reductase inhibitor, finasteride (Proscar) or dutasteride (Avodart), will not only improve symptoms, but reduce the likelihood of urinary retention, especially if the patient has an elevated PSA level in the absence of cancer.”
“These days some urologists are putting these patients on anticholinergics. Before we do that on a large scale though, I think we need more and bigger studies. Lots of family doctors treat men with LUTS and are not ready to put patients on anticholinergics because we don't yet know if they're safe and effective long-term.”
Dr. Paterson says it's important to check a urine cytology in patients with irritative voiding symptoms, and many urologists will then proceed to cystoscopy in this patient group. He also takes a thorough dietary history. “Dietary change is something we need to stress more: avoiding or limiting caffeinated beverages, acidic and spicy foods, and alcohol,” he says. “We also need to tell male patients to do Kegel exercises and discuss fluid restriction.” Only then does he bring up pharmacologic therapy. “If a patient has obstructive, irritative, or mixed voiding symptoms, and no absolute need for surgery, you can start with an alpha blocker and see how he does.”
Drug costs a factor
Some patients, he adds, will still have pronounced symptoms. For them, combination treatment with alpha blockers and anticholinergics may be appropriate. “I also think it's important to talk to patients about what their drug plans will cover; there's no point in putting patients on a drug that's going to cost $50 a month if they can't afford it. Physicians and patients also should discuss the fact that symptoms can fluctuate.”
Dr. Staskin points out that women with OAB and men with OAB who are not obstructed will have the same symptoms, and both will respond to anticholinergic therapy. “In the past, anticholinergic drugs were thought to be unsafe in men. The presumption was that men would go into urinary retention because the prostate was blocking the urethra,” Dr. Staskin says. “Now we've changed our minds somewhat; we don't think the drugs affect contractility as much as we used to. Data shows that if you've treated obstruction with alpha blockers or 5-alpha-reductase inhibitors, you can add an anticholinergic. Studies suggest that men with smaller prostates do better on combination therapy.”
What's in the pipeline?
Severe OAB cases that resist all available conventional treatments present a therapeutic dilemma, but promising new therapies are under investigation. Michael Chancellor, MD, at the University of Pittsburgh, has reported good results injecting botulinum toxin into the base of the bladder. Use of the toxin for OAB is not yet FDA approved, however.