Medication Summary
Pharmacologic management plays an important role in the treatment of bedwetting. Three pharmacologic approaches are currently considered: desmopressin acetate, anticholinergic medications, and imipramine.
Vasopressin-Related
Class Summary
Secretion of vasopressin at night reduces urine output. Water is conserved and concentrated by increasing the flow in the kidney through the collecting tubules to the medullary interstitium.
Desmopressin acetate is a synthetic analogue of antidiuretic hormone (ADH). The mechanism of action is presumed to be a reduction in overnight production of urine.
It was later found that some children with bedwetting had lower nocturnal levels of ADH than children who were dry at night.
This finding provided a scientific rationale for desmopressin use; however, not all children with bedwetting have lower levels of ADH at night, overproduce urine at night, or respond to desmopressin. In addition, not all children who respond to desmopressin have lower levels of ADH or overproduce urine at night before being treated with the medication.
Desmopressin, oral (DDAVP)
Desmopressin increases the cellular permeability of collecting ducts, resulting in reabsorption of water by kidneys. It is formulated as a tablet, a disintegrating melt, and as a nasal spray. Because of the risk for severe hyponatremia, the intranasal formulation is no longer indicated for primary enuresis.
Antispasmodic Agents, Urinary
Class Summary
Most children with bedwetting have a small functional bladder capacity at night. Other children with bedwetting also have daytime symptoms of frequency and urgency. These children might benefit from treatment with an anticholinergic medication that allows the bladder to hold more urine. Outside of these situations, treatment with an anticholinergic medication is not likely to decrease the incidence of bedwetting.
Oxybutynin (Ditropan XL, Gelnique, Oxytrol)
Oxybutynin should be considered in children who are likely to have small functional bladder capacity either only at night or throughout the day. Daytime symptoms that might indicate potential for therapeutic benefit include frequency, urgency, and incontinence. Nighttime symptoms include wetting more frequently than once per night. It is not approved for children younger than 12 years.
Tolterodine (Detrol, Gelnique, Oxytrol)
Tolterodine is a competitive muscarinic receptor antagonist for overactive bladder; it differs from other anticholinergic drugs in that it has selectivity for the urinary bladder over salivary glands. Tolterodine is used in patients likely to have small functional bladder capacity either only at night or throughout the day. Daytime symptoms that may indicate potential for therapeutic benefit include frequency, urgency, and incontinence. Nighttime symptoms include wetting more frequently than once per night.
Flavoxate (Urispas)
Flavoxate is used for symptomatic relief of incontinence. It has anticholinergic effects and exerts a direct effect on muscle. It counteracts smooth muscle spasm of the urinary tract.
Antidepressants, TCAs
Class Summary
Imipramine was first prescribed for bedwetting in an era when psychological causes were considered common. The modern understanding is that psychological causes are not a cause of enuresis. The mechanism whereby imipramine improves bedwetting is not clear. Current theories include central nervous system (CNS)-related or local bladder-related effects.
Imipramine (Tofranil)
Imipramine facilitates urine storage by decreasing bladder contractility and increasing outlet resistance. It inhibits reuptake of norepinephrine or serotonin at the presynaptic neuron.
Tables
Age, y |
Dry by Day, % |
Dry by Night, % |
2 |
25 |
10 |
2.5 |
85 |
48 |
3 |
98 |
78 |
Causes of Primary Enuresis |
Causes of Secondary Enuresis |
Idiopathic Disorder of sleep arousal Nocturnal polyuria Small nocturnal bladder capacity |
Idiopathic Disorder of sleep arousal Nocturnal polyuria Small nocturnal bladder capacity |
Overactive bladder or dysfunctional voiding |
Overactive bladder or dysfunctional voiding |
Cystitis |
Cystitis |
Constipation |
Constipation |
Neurogenic bladder |
Psychological |
Urethral obstruction |
Acquired neurogenic bladder |
Psychological |
Seizure disorder |
Ectopic ureter |
Obstructive sleep apnea |
Diabetes insipidus |
Diabetes mellitus |
|
Acquired diabetes insipidus |
|
Acquired urethral obstruction |
