Medicine Treatments for Bedwetting

Desmopressin

Desmopressin is the most popular medicine used to treat bedwetting. A dose is given just before bedtime. It comes both in tablet form which is swallowed, or as a 'melt' tablet - that is, one you put under the tongue, which dissolves and goes straight into the bloodstream. The advantage of the melt form is that it is not affected by food in the stomach. (There used to be a nasal spray option. However, this is no longer prescribed for children due to an increase risk of side effects compared to the tablet and 'melt' preparations.)

How does desmopressin work?

It works mainly by reducing the amount of urine made at night by the kidneys. Therefore, the bladder does not fill very much with urine in the night.

How effective is desmopressin?

Most children who take desmopressin will have an improvement. This may be less wet nights than usual rather than being totally dry every night. About 1 in 5 children who take desmopression are totally dry whilst on treatment.

What are the advantages of desmopressin?

Because of the way it works (reducing the amount of urine being made), it has an immediate effect on the first night of treatment. This can be very encouraging to the child.

If it has had no effect after a few days, it is unlikely to work at all. However, sometimes the initial dose is not high enough. A doctor may advise to increase the dose if it does not work at first. Also, it is possible that food can affect the absorption of desmopressin tablets into the body. Therefore, if it has not worked, then try giving the dose at least an hour and a half after the child last ate anything, and don't give food to your child just before bedtime. Alternatively you could try the 'melt' (under the tongue) preparation.

What are the disadvantages of desmopressin?

It does not work in all cases. Also, in children where it has worked, when it is stopped there is a high chance that bedwetting will return. (A permanent cure following treatment is more likely with bedwetting alarms than with desmopressin. See leaflet called 'Bedwetting Alarms' for details.) Some children develop side-effects, but these are rare.

When and how is desmopressin used?

It is generally used only in children over seven years, but sometimes in children a year or two younger. If it works, it can be continued for a while. After three months of treatment, desmopressin should be stopped for at least one week to assess if it is still needed. Treatment with bedwetting alarms is discussed in another leaflet. However, some children remain dry after a course of desmopressin is stopped.

Desmopressin can also be useful for short spells. For example, it may be especially helpful for holidays or times away from home (sleepovers, etc). It may also give encouragement to a child who is fed up with bedwetting to have a period of dry nights.

The child should only drink a small amount of fluid before and after a dose of desmopressin - see below.

Are there any side-effects with desmopressin?

Side-effects are rare. Read the packet leaflet for a list of all possible side-effects. They include headache, feeling sick, and mild tummy pain. These side-effects are not serious and go away if the treatment is stopped.

The most serious possible side-effect is due to the way the medicine works - it reduces the amount of urine that is made. Very rarely, this can lead to fluid overload (too much fluid in the body). This may lead to convulsions and serious problems. It has to be stressed that this is rare and unlikely to happen. However, as a precaution, it is advised that when a child takes desmopressin:

• He or she should not drink too much in the evening. Normal amounts to ease thirst are fine, but not extra drinks for pleasure, such as cans of lemonade.
• He or she should not drink more than one mug of liquid (about 240 ml) from one hour before taking desmopressin to eight hours afterwards.

In effect, this means just give small drinks if your child is thirsty in the night.

Also, do not give desmopressin to a child who is ill with diarrhoea or vomiting until the illness has cleared. Children with vomiting and diarrhoea should be given plenty of fluids.

Tricyclic antidepressant medicines

Medicines called 'tricyclic antidepressants' have been used for many years to treat bedwetting. They include imipramine, amitriptyline, and nortriptyline. A dose is given just before bedtime.

How do tricyclic antidepressant medicines work for bedwetting?

It is not clear how they work. It has nothing to do with their antidepressant action. They seem to have an additional effect on the bladder.

How effective are tricyclic antidepressant medicines at treating bedwetting?

The success rate is about the same as desmopressin. As with desmopressin, there is a high chance that the bedwetting will return when treatment is stopped.

When is a tricyclic antidepressant medicine used?

They are generally only used in children over seven years. These medicines are not as popular as desmopressin. This is because there is a higher chance that side-effects may occur. Also, these medicines are dangerous in overdose. So keep them away from children. However, a tricyclic antidepressant is an option if desmopressin has been tried not worked.

What are the possible side-effects?

Most children do not get side-effects. However, they are more likely to occur than with desmopressin where side-effects are rare. They include: dry mouth, constipation, blurred vision, tremor, agitation, anxiety, sleepiness, insomnia (poor sleep). If any of these side-effects occur they will go if the medicine is stopped. A rare but serious side-effect is a heart disturbance. See the leaflet that comes with the packet of medicine for a full list of possible side-effects.

Further information and help

ERIC - Education and Resources for Improving Childhood Continence

34 Old School House, Britannia Road, Kingswood, Bristol, BS15 8DB
Tel (helpline): 0845 370 8008 Tel (admin): 0117 960 3060 Web: www.eric.org.uk
Provides support and information (including booklets, CD-ROM, DVD, and video), and sells a range of products including alarms, mattress and bedding covers, waterproof duvets, etc.