Monday, December 8, 2014

Desmopressin works for adults with nocturia, too

- Jennifer Middleton, MD, MPH

Desmopressin has been a staple in the treatment of pediatric nocturia for years, and the December 1 issue of AFP reviews a recent systematic review describing desmopressin's effectiveness for adults as well.

The systematic review examined 10 randomized controlled trials (RCTs) of varied quality with approximately 2200 patients in total. The average age of participants ranged from 55-74 years, and men and women were both represented. All of the RCTs compared desmopression to placebo (1 compared desmopression plus furosemide to placebo).

Here is the decrease in the mean number of voids for each dose:

25 mcg = 0.38 [95% CI 0.09, 0.48] fewer voids/night
50 mcg = 0.44 [95% CI 0.16, 0.72] fewer voids/night
100 mcg = 0.72 [95% CI 0.48, 0.96] fewer voids/night

And, here is the increase in time until first waking to void:
"low dose" (less than 100 mcg) = 42.18 more minutes [95% CI 19.94, 64.42]
"high dose" (100 mg or higher) = 68.30 more minutes  [95% CI 39.42, 97.17]

Desmopressin does reduce nocturia, and it is a reasonable option to offer adult patients. The included RCTs did not, however, assess participant satisfaction. Did participants feel more rested the next morning? Was their quality of sleep better? How about their quality of life? Is an extra 42-68 minutes of sleep before waking up to go to the bathroom meaningful to patients? Without participant satisfaction studies, physicians are left to interpret for themselves the clinical significance of this data.

After all, statistical significance doesn't always equal clinical significance. To the authors' credit, they broach these same questions in their discussion section. Studies looking specifically at participant satisfaction could aid patient-physician decision making. Using desmopression may involve some patient-centered decision making; physicians may choose to share the above data with patients, perhaps also with the number needed to harm (NNH) of 20 for the side effect of hyponatremia, and let patients decide if it is worthwhile to give desmopressin a try.

Evidence-based medicine is the intersection of evidence, clinician expertise, and patient preference. Desmopressin decreases nocturia, but will patients be happy with the difference?  The answer will likely vary from patient to patient and from clinician to clinician. There's an AFP article on "Sleep Problems in the Elderly" if you'd like to read more broadly about this topic.

How does your office care for adults with nocturia?