desmopressin in nocturnal enuresis

Last reviewed 01/2018

NICE have issued guidance with respect to the use of desmopressin in nocturnal enuresis. Summary points include (1):

• desmopressin should be offered to children and young people over 7 years, if:
  • rapid-onset and/or short-term improvement in bedwetting is the priority of treatment or an alarm is inappropriate or undesirable
• consider desmopressin for children aged 5-7 years if treatment is required and:
  • rapid-onset and/or short-term improvement in bedwetting is the priority of treatment or
  • an alarm is inappropriate or undesirable
• desmopressin can be used as an option for the management of bedwetting in children and young people who also have daytime symptoms. However, do not use desmopressin in the treatment of children and young people who only have daytime wetting
• in children and young people who are not completely dry after 1 to 2 weeks of the initial dose of desmopressin (200 micrograms for Desmotabs or 120 micrograms for DesmoMelt), consider increasing the dose (to 400 micrograms for Desmotabs or 240 micrograms for DesmoMelt)
• assess the response to desmopressin at 4 weeks and continue treatment for 3 months if there are signs of a response. Consider stopping if there are no signs of response. Signs of response include:
  • smaller wet patches
  • fewer wetting episodes per night
  • fewer wet nights
• NICE also state that (1):
  • desmopressin should not be excluded as an option for the treatment of bedwetting in children and young people with sickle cell disease if an alarm is inappropriate or undesirable and they can comply with night-time fluid restriction. However the clinician must provide advice about withdrawal of desmopressin at times of sickle cell crisis
  • desmopressin should not be excluded as an option for the treatment of bedwetting in children and young people with emotional, attention or behavioural problems or developmental and learning difficulties if an alarm is inappropriate or undesirable and they can comply with night-time fluid restriction
  • do not routinely measure weight, serum electrolytes, blood pressure and urine osmolality in children and young people being treated with desmopressin for bedwetting
  • consider advising that desmopressin should be taken 1-2 hours before bedtime in children and young people with bedwetting that has either partially responded or not responded to desmopressin taken at bedtime. Ensure that the child or young person can comply with fluid restriction starting from 1 hour before the drug is taken
  • consider continuing treatment with desmopressin for children and young people with bedwetting that has partially responded, as bedwetting may improve for up to 6 months after starting treatment

Twenty-four cases of hyponatraemic convulsions after the use of vasopressin spray have been reported to the Committee on Safety of Medicines. They recommend that the risk of this rare side effect is minimised by:

• avoid concomitant use of drugs that may increase endogenous vasopressin e.g. tricyclics
• follow the recommended starting doses for vasopressin
• warn against excessive fluid intake:

Fluid intake should be "limited" from 1 hour before until 8 hours after administration... in addition, the child should avoid ingesting water while swimming (3)

• if vomiting or diarrhoea occurs then temporarily stop vasopressin

Previous guidance had suggeted that desmopressin should be stopped for a week while the child is reassessed at 3-monthly intervals, and a prescription should not be provided for more than 3 months at a time (3).

This treatment should also not be administered to any child with renal disease, cystic fibrosis, cardiovascular disease or who is being treated with diuretics (4).

Because of the serious adverse effects associated with the nasal spray formations, oral formations of desmopressin are recommended (5).

The summary of product characteristics must be consulted before prescribing this drug.

Reference:

1. NICE (October 2010).Nocturnal enuresis - The management of bedwetting in children and young people
2. CSM/MCA (1996), hyponatraemic convulsions in patients with enuresis treated with vasopressin, Current Problems in Pharmacovigilance, 33, 4.
3. Drug and Therapeutics Bulletin (2004); 42(5):33-37.
4. Prescriber (2001), 12 (5), 103-8.
5. MHRA (2007) Desmopressin nasal spray: removal of the primary nocturnal enuresis (bedwetting) indication. Medicines and Healthcare products Regulatory Agency