medications for bedwetting

by Diane K. Newman, RNC, MSN, CRNP, FAAN

Desmopressin acetate, a synthetic analogue of the antiduretic hormone vasopressin, increases renal (kidney) tubular reabsorption of water, resulting in decreased urine output. It is effective in 60 percent of children with the highest success rate in those with primary monosymptomatic nocturnal enuresis. It can be taken as a pill or a nasal spray, and used either nightly or as needed for special occasions such as sleepovers, camp and vacation, provided its efficacy has been demonstrated prior to the event.

Desmopressin (DDAVP) may be given at a starting dose of 0.2 mg, titrating up to 0.6 mg as needed, and evening and nighttime fluids must be restricted. Side effects of desmopressin include headache and, if fluid is not restricted in the evening, hyponatremia (lower than normal concentration of sodium in the blood.)

An anticholinergic medication such as oxybutynin or tolterodine may be used alone or in combination with desmopressin in children with bladder overactivity or who appear to have a low functional bladder capacity. A detailed voiding history, including frequency, urgency and the presence of wetting or dampening, as well as the number of times a child wets per night can help identify children who might benefit from anticholinergic therapy. Side effects of these medications include dry mouth and constipation.

Imipramine hydrochloride, a tricyclic antidepressant used to treat mood disorders, has been used to manage nocturnal enuresis since the 1960s. Its mechanism of action is not well understood, but it is believed to (1) alter the sleep pattern so that the child arouses more easily when the bladder becomes full, and (2) have an anticholinergic effect that decreases the frequency and intensity of bladder contractions and allows the bladder to hold a greater volume. The initial success rate for Imipramine is near 30 to 50 percent, however, relapse is high when the medication is discontinued. The side effects of imipramine can be significant and include mood and behavior changes, insomnia and EKG changes. Safety precautions must be discussed with families, as an overdose of Imipramine can be lethal.

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