In 2009, the Agency for Healthcare Research and Quality carried out an evidence-based review of the large body of literature on pharmacologic therapies for urinary urgency incontinence and overactive bladder (61). Estimates from their meta-analysis models suggest that immediate-release forms of medications (oxybutynin, short-acting tolterodine) decreased incontinence episodes and voids by 1.46 and 2.16 per day, respectively. Extended-release forms of medications (tolterodine, trospium chloride, solifenacin, oxybutynin) decreased incontinence episodes and voids by 1.78 and 2.24 per day, respectively. However, placebo also impacted continence, decreasing incontinence episodes and voids by 1.08 and 1.48 per day, respectively. Whether or not the improvements observed with medication are clinically significant depends on patients’ perceptions and initial level of severity. In the randomized trials reviewed, baseline episodes of incontinence ranged from 1.6 to 5.3; decreasing this by one or two may or may not constitute a successful outcome for a given patient.
When initiating therapy with generic oxybutynin, it is best to start with a lower dose (particularly for elderly patients) and increase it as needed to a higher, more frequent dosage. Patients should be encouraged to titrate their medication to their symptoms and to vary the dosage (within acceptable limits) according to their needs. If this is not effective, the next step is to move to one of the other anticholinergic agents. Some women may respond better to one agent than another. A 2-week trial is sufficient to determine effectiveness. It is helpful to ask patients to record daily episodes of incontinence or urgency before and during therapy so effectiveness can be more accurately determined.
Patients should be warned of the side effects of anticholinergic agents. Patients should be particularly advised about the symptom of a dry mouth and told that this is not caused by thirst. Some patients increase their ﬂuid intake to combat this problem, with a subsequent worsening of their incontinence. If dry mouth is a problem, patients should relieve it by chewing gum, sucking on a piece of hard candy, or eating a piece of moist fruit.
Table 26.9 Commonly Used Medications for Urge Incontinence tid, three times a day; qid, four times a day; qd, every day; bid, twice a day. aAvailable as generic.bWatson Pharmaceuticals. cPfizer. dAllergan. eAstellas Pharmaceuticals.
f 7.5 or 15 mg by mouth
Medications that treat nocturia and nocturnal enuresis have one of three aims: (i) to reduce urine output, (ii) to increase bladder capacity and reduce unstable bladder contractions, and (iii) to act centrally on sleep and micturition centers.
An analogue of arginine vasopressin, DDAVP, is used extensively to treat children with nocturnal enuresis. Some studies suggest that it may be useful in adults (62,63). It is available as a nasal spray and as an oral preparation. When taken orally, the dose required is approximately 10 times greater because of the increased availability of the nasal preparation. Complications associated with the DDAVP include hyponatremia, particularly in patients with excessive ﬂuid intake; therefore, it is essential in higher-risk patients to measure serum sodium levels periodically.
There are few clinical trials that specifically investigate the use of anticholinergic medications to treat nocturia or nocturnal enuresis. Anecdotal evidence supports a trial of a long-acting or extended-release form of an anticholinergic, taken approximately 1 hour before bedtime.