From the Guidelines
The recommended dose of imipramine for nocturnal enuresis is 25 to 50 mg at bedtime, with the larger dose given to children older than 9 years. This dosage is based on the most recent and highest quality study available, which evaluated the treatment for monosymptomatic enuresis 1. The study suggests that imipramine is effective in approximately 50% of unselected children with enuresis, but due to safety concerns and side effects, it is only relevant as third-line therapy at tertiary care facilities.
Key Considerations
- The effect of imipramine is evaluated after 1 month of treatment 1.
- When there is a partial response, desmopressin at the standard dose may be added, provided that the fluid intake of the child is restricted during the evening and night 1.
- If treatment is successful, the family should taper to the lowest effective dose and ensure that regular drug holidays of at least 2 weeks are interspersed every third month or so to decrease the risk of tolerance 1.
- Imipramine should be kept securely locked and out of reach of smaller siblings due to the risk of serious toxicity in overdose 1.
- A history of palpitations or syncope in the child, or any sudden cardiac death or unstable arrhythmia in the family, requires exclusion of long QT syndrome by prolonged electrocardiogram recording before imipramine treatment is considered 1.
Side Effects and Monitoring
- Patients should be monitored for side effects including dry mouth, constipation, drowsiness, and rarely, cardiac effects 1.
- Moderate side effects often gradually disappear even if treatment is continued 1.
- Imipramine works by increasing bladder capacity and decreasing detrusor muscle activity through its anticholinergic effects, while also potentially affecting arousal thresholds during sleep 1.
From the FDA Drug Label
Initially, an oral dose of 25 mg/day should be tried in children aged 6 and older. Medication should be given one hour before bedtime If a satisfactory response does not occur within one week, increase the dose to 50 mg nightly in children under 12 years; children over 12 may receive up to 75 mg nightly. The recommended dose of imipramine for nocturnal enuresis is:
- 25 mg/day initially in children aged 6 and older, given one hour before bedtime
- May be increased to 50 mg nightly in children under 12 years if no response occurs within one week
- May be increased to 75 mg nightly in children over 12 years if no response occurs within one week
- A daily dose greater than 75 mg does not enhance efficacy and tends to increase side effects 2
From the Research
Recommended Dose of Imipramine for Nocturnal Enuresis
The recommended dose of imipramine for nocturnal enuresis is not explicitly stated in the provided studies, but the following information can be gathered:
- A study published in 2019 3 used a dose of 5 mg imipramine at bedtime in combination with desmopressin for the treatment of primary nocturnal enuresis.
- A study published in 1997 4 used a single oral dose of imipramine (1 mg/kg of body weight) taken at 8 p.m. to investigate its effect on nocturnal urine output in patients with nocturnal enuresis.
- Other studies 5, 6, 7 do not provide specific information on the recommended dose of imipramine for nocturnal enuresis.
Key Findings
- The use of imipramine in combination with desmopressin may be an effective treatment option for primary nocturnal enuresis 3.
- Imipramine has a vasopressin-independent antidiuretic effect in patients with nocturnal polyuria 4.
- The effectiveness of imipramine in treating nocturnal enuresis may vary depending on the individual patient and the presence of other underlying conditions 5, 6, 7.