Tricyclic Antidepressants
Tricyclic antidepressants are not used often. The mechanism of action is unclear, however, it is thought to relate to their noradrenergic action at the brainstem. Imipramine, desipramine, amitriptyline, and nortriptyline have been studied and shown efficacy in treating nocturnal enuresis, but imipramine has the most evidence.
Efficacy
Imipramine has been studied the most and is effective for 40-60% of patients. Response is seen within the first week. Trials comparing imipramine and desmopressin have shown that imipramine is inferior.
A Cochrane review showed that 80% of children stopped bedwetting when using a tricyclic antidepressant, but this effect was not sustained after discontinuation. There is a high rate of relapse.
Safety
Tricyclic antidepressants have more side effects than desmopressin. These include dry mouth, constipation, gastrointestinal upset, insomnia, and postural hypotension. Overdosing can lead to cardiotoxic and hepatotoxic effects. This causes hesitancy in both parents and clinicians to start children on these agents. They are not the first choice of medication for this indication.
Dosing
Starting dose for six years of age or older is 25mg imipramine given 30 minutes prior to going to bed. This can be titrated to a usual dose of 1-2.5mg/kg/night.
Efficacy
Imipramine has been studied the most and is effective for 40-60% of patients. Response is seen within the first week. Trials comparing imipramine and desmopressin have shown that imipramine is inferior.
A Cochrane review showed that 80% of children stopped bedwetting when using a tricyclic antidepressant, but this effect was not sustained after discontinuation. There is a high rate of relapse.
Safety
Tricyclic antidepressants have more side effects than desmopressin. These include dry mouth, constipation, gastrointestinal upset, insomnia, and postural hypotension. Overdosing can lead to cardiotoxic and hepatotoxic effects. This causes hesitancy in both parents and clinicians to start children on these agents. They are not the first choice of medication for this indication.
Dosing
Starting dose for six years of age or older is 25mg imipramine given 30 minutes prior to going to bed. This can be titrated to a usual dose of 1-2.5mg/kg/night.
References:
Gorodzinsky FP. Genitourinary Disorders: Urinary Incontinence in Children. In: e-Therapeutics+. Ottawa, ON: Canadian Pharmacists Association; 2013. https://www.e-therapeutics.ca/tc.showChapter.action?documentId=c0052. Updated May 2011. Accessed Mar 20, 2013.
Kiddoo DA. Nocturnal enuresis. CMAJ . 2012;184(8):908-11.
O’Flynn N. Nocturnal enuresis in children and young people: NICE clinical guideline. Br J Gen Pract. 2011;61(586):360-62.
Gorodzinsky FP. Genitourinary Disorders: Urinary Incontinence in Children. In: e-Therapeutics+. Ottawa, ON: Canadian Pharmacists Association; 2013. https://www.e-therapeutics.ca/tc.showChapter.action?documentId=c0052. Updated May 2011. Accessed Mar 20, 2013.
Kiddoo DA. Nocturnal enuresis. CMAJ . 2012;184(8):908-11.
O’Flynn N. Nocturnal enuresis in children and young people: NICE clinical guideline. Br J Gen Pract. 2011;61(586):360-62.