Imipramine has been used to treat bedwetting since the 1960s. It predates bedwetting alarms, desmopressin, and most of the interventions now recommended in clinical guidelines — yet it has never fully disappeared from practice. If your child’s GP or paediatrician has mentioned it, or if you’ve come across it in your own research, here is a straightforward account of what it does, how well it works, and what the safety considerations actually mean.
## What Is Imipramine?
Imipramine is a tricyclic antidepressant. It was originally developed to treat depression in adults and is still used for that purpose. Its effect on bedwetting was noticed incidentally and has been used off-label for nocturnal enuresis for decades. It is not a first-line treatment in current UK guidelines, but it remains a licensed option and is listed in the British National Formulary (BNF) for children aged seven and over.
It is available in tablet form and is usually taken once daily, shortly before bedtime.
## How Does Imipramine Work for Bedwetting?
The exact mechanism is not fully understood, but several theories have been proposed:
– **Anticholinergic effect:** Imipramine relaxes the bladder muscle, reducing urgency and increasing functional bladder capacity.
– **Antidiuretic effect:** It may increase ADH (antidiuretic hormone) secretion, reducing overnight urine production — similar in effect to desmopressin, though less predictable.
– **Sleep architecture changes:** Some researchers suggest it alters sleep depth, making children more arousable. This theory has largely fallen out of favour but hasn’t been entirely disproved.
– **Central nervous system effects:** As a tricyclic, imipramine acts on multiple receptor systems, which may contribute to its effect through pathways not yet clearly mapped.
In practice, it is likely that the bladder and antidiuretic effects together account for most of the clinical benefit.
## How Effective Is It?
Imipramine produces a meaningful response in around 40–50% of children — typically a significant reduction in wet nights rather than complete dryness. Full dryness while on the medication occurs in roughly 20–30% of cases, depending on the study and dose.
Relapse is common; when imipramine is stopped, over 50% of children may return to their previous wetting pattern. This makes it more suitable as a short-term management tool, for example before a school trip or holiday.
Compared to bedwetting alarms, which achieve full dryness in approximately 60–70% of users with a lower relapse rate, and desmopressin, which offers reliable short-term suppression, imipramine is generally considered after these first-line options have failed or are unsuitable, as per NICE guidance (CG111).
## Who Might Be Offered Imipramine?
Imipramine is more likely to be considered when:
– First-line treatments like alarms and desmopressin have been tried without success
– Desmopressin is contraindicated or poorly tolerated
– There is a specific short-term need, such as a trip, where other options are impractical
– A specialist has reviewed the case and considers it appropriate alongside other management strategies
It is typically prescribed by specialists, not GPs, due to cardiac safety considerations. If your child’s case reaches this stage, you are likely working with a paediatrician or continence clinic. If concerns are not being addressed, see our guide on [what to do when a GP isn’t listening](#).
## Safety and Side Effects: What the Concerns Actually Are
### Cardiac Risk
Imipramine affects cardiac conduction, specifically the QT interval. In overdose, this can cause serious arrhythmias. Documented cases exist of accidental poisoning in children who accessed medication meant for adults or received excessive doses.
At therapeutic doses, the cardiac risk is low, but the safety margin is narrower than with desmopressin. Therefore, careful management is essential:
– Baseline ECG before starting, and sometimes during treatment
– Weight-adjusted dosing, reviewed regularly
– Strict storage out of reach of children and siblings
– Clear guidance on missed or double doses
If a prescriber does not discuss storage safety and cardiac monitoring, ask explicitly about both.
### Other Side Effects
Common, usually mild, and transient side effects include:
– Dry mouth
– Constipation (noting that constipation can contribute to bedwetting)
– Mild morning sedation
– Mood changes, such as irritability or low mood (more common at higher doses)
– Reduced appetite
Constipation should be flagged, especially if already an issue.
### Interactions
Imipramine interacts with several medications, including ADHD medications, antihistamines, and epilepsy treatments. Confirm with the prescriber that interactions have been reviewed before starting.
## Practical Points If Imipramine Is Prescribed
1. **Start low, go slow:** Typical starting dose is 25mg for children aged 7–11, with possible increases if response is partial. Regular review is essential.
2. **Allow at least two weeks:** Response may take time; a four-week trial is common.
3. **Do not stop abruptly:** Discontinuation symptoms like nausea and sleep disturbance can occur.
4. **Keep a record:** Track wet and dry nights to assess response.
5. **Secure storage:** Lockable medication storage is essential, especially with other children in the household.
## Imipramine Alongside Other Management
Medication alone rarely resolves bedwetting; attention to fluid management, toileting routines, and bedding protection remains important. If frequent wet nights persist despite treatment, consider reading articles on why overnight pull-ups leak and how to stop leg leaks.
There is also an emotional dimension, especially for older children with multiple treatment attempts. For these families, [this guide on next steps when nothing has worked](#) offers broader options.
## What the Guidelines Say
NICE guideline CG111 recommends imipramine as third-line, after alarms and desmopressin. It states that it should only be prescribed or supervised by a paediatrician or specialist and that treatment should not exceed three months without review.
The guideline highlights that bedwetting often resolves spontaneously and that benefits must be weighed against risks, especially in children under seven, for whom imipramine is not recommended.
## A Realistic Summary
Imipramine is a legitimate, evidence-based option with a long history, but it has a narrower safety margin than alternatives. It is most useful when first-line treatments have failed, or a specific short-term goal exists, with a specialist’s input. Cardiac safety considerations are real and require proper management.
If your child has been offered imipramine, ensure you understand monitoring requirements, secure storage, and systematically track responses. If considering specialist input, see [when to see a doctor](#).
