Convulsion and coma after intranasal desmopressin in cystic fibrosis

Severe signs of hyponatremia secondary to desmopressin treatment for enuresis: a systematic review

OBJECTIVE

Dilutional hyponatremia is a serious adverse effect of desmopressin, a vasopressin analog that is widely prescribed to manage monosymptomatic enuresis. The presentation of hyponatremia, largely related to cerebral dysfunction, can include severe signs like altered mental status and seizures.

METHODS

We reviewed the literature dealing with altered mental status or seizures in enuretic subjects on desmopressin. The retained publications included patients who were described individually, revealing data on mode of administration, further identifiable factors predisposing to hyponatremia, presentation and clinical course.

RESULTS

We found 54 cases of hyponatremia secondary to desmopressin treatment presenting with altered mental status or seizures. In most cases the complication developed 14 days or less after starting desmopressin. An intranasal formulation had been used in 47 patients. Excess fluid intake was documented as a contributing factor in at least 22 cases. In 6 cases severe signs of hyponatremia developed in the context of intercurrent illnesses.

CONCLUSION

Altered mental status or seizures are very rare but recognized complications of desmopressin in enuresis. This complication mostly develops in subjects managed with the intranasal formulation 14 days or less after starting the medication, following excess fluid intake and during intercurrent illnesses.

Desmopressin is a safe drug for the treatment of enuresis

OBJECTIVE

To verify the safety of desmopressin treatment and its associated side-effects in a large number of patients.

MATERIAL AND METHODS

The study was conducted in accordance with the guidelines of the Italian Club for Nocturnal Enuresis, whose criteria are: age >5 years; absence of malformations and infections of the urinary tract; absence of psychological disorders or neurological alterations; number of "wet nights" >5-7; control of liquid intake during the afternoon and evening; monitoring of serum electrolytes before beginning treatment; control of body weight before the beginning of treatment and during the first 4-5 days of therapy; and the informed consent of the parents. The therapeutic regimen provided for a maximum dose of desmopressin of 40 microg/day (four puffs/nostril or two tablets), starting from an initial dosage of 20 microg/day (two puffs/nostril or one tablet) 1 h before going to bed. The study involved two groups of patients with monosymptomatic enuresis: some of them had been administered desmopressin in the form of a spray and others in the form of tablets.

RESULTS

A small percentage of patients presented mild, transient side-effects; in no case were severe side-effects verified.

CONCLUSION

Desmopressin is a safe drug with a low incidence of side-effects.

The comparative safety of oral versus intranasal desmopressin for the treatment of children with nocturnal enuresis

PURPOSE

Desmopressin is a well established and effective therapy for nocturnal enuresis. Water intoxication leading to hyponatremia is an infrequent but serious adverse event associated with desmopressin. We assessed the safety of desmopressin in children 18 years or younger with nocturnal enuresis with a focus on the relative safety of the oral compared with the intranasal formulation.

MATERIALS AND METHODS

Published data (MEDLINE) from December 1972 to August 2006 and post-marketing safety data from December 1972 to June 2005 were analyzed.

RESULTS

A total of 21 clinical trials on desmopressin use in children with nocturnal enuresis were identified. There were no reports of hyponatremia. A total of 21 publications were identified that included 48 case reports of hyponatremia in children with nocturnal enuresis. In all case reports patients were treated with intranasal desmopressin. Post-marketing safety data included 151 cases of hyponatremia in children with nocturnal enuresis, of whom 145 were treated with intranasal desmopressin and 6 were treated with the tablet formulation. Prodromal symptoms of hyponatremia were identified as headache, nausea and vomiting.

CONCLUSIONS

Data suggest that there is a decreased risk of hyponatremia with oral desmopressin compared with intranasal desmopressin. Identifiable and preventable risk factors for hyponatremia are inappropriately high fluid intake, administration of a larger than recommended dose, young age (less than 6 years) and concomitant administration of another medication. When desmopressin is prescribed, patients should be instructed to avoid high fluid intake when the medication is ingested, not ingest a higher than recommended dose and promptly discontinue the medication and seek assessment if headache, nausea or vomiting develops.

Hyponatraemic convulsion secondary to desmopressin treatment for primary enuresis

The case of a 6 year old child who presented with convulsions and coma after unsupervised self administration of intranasal desmopressin (DDAVP) for nocturnal enuresis is presented. Children with enuresis can be embarassed by their condition and may believe that multiple doses of their nasal spray may bring about a rapid resolution. Water intoxication is an uncommon but serious adverse effect of treatment with intranasal DDAVP. These patients may present with seizure, mental state changes, or both. Basic management consists of stopping the drug, fluid restriction, and suppressive treatment for seizures. Recovery is usually rapid and complete. Administration of the nasal spray in children should be supervised by parents to prevent highly motivated children from accidental overdose. The risks of high fluid intake need to be carefully explained to both parents and children.

Hyperkalaemic paralysis--a bizarre presentation of renal failure

Paralysis due to hyperkalaemia is rare and the diagnosis may be overlooked in the first instance. However it is rapidly reversible and so long as electro-cardiography and serum potassium measurement are urgently done in all patients presenting with paralysis, it will not be missed. A case of hyperkalaemic paralysis is described and a review of the emergency management discussed.

Hyponatremia in patients with nocturnal enuresis treated with DDAVP

Treatment of nocturnal enuresis with DDAVP is associated with a low incidence of adverse effects. The only reported serious adverse effect is seizure or altered level of consciousness due to water intoxication. We reviewed 14 articles that reported data on serum sodium in patients treated with DDAVP for nocturnal enuresis and 11 articles that reported patients who developed a seizure or altered level of consciousness during treatment with DDAVP for nocturnal enuresis. Excess fluid intake was identified as a contributing factor in 6 of the 11 case reports.

CONCLUSION

Hyponatremia is a potential adverse effect in patients with nocturnal enuresis who are treated with DDAVP. To prevent this adverse effect we recommend that the patients prescribed DDAVP for nocturnal enuresis should be counseled not to ingest more than 240 ml (8 ounces) of fluid on any night that DDAVP is administered.

Hyponatraemia and cerebral convulsion due to short term DDAVP therapy for control of enuresis nocturna

Desmopressin (DDAVP) is frequently used in the treatment of primary isolated enuresis nocturna if other approaches have failed. We report a further case of hyponatraemia and cerebral convulsion due to water intoxication after intranasal DDAVP application by a 6 year-old boy with enuresis.

CONCLUSION

Although adverse reactions in DDAVP (e.g. hyponatraemia) are rare, it should not be considered as the first choice treatment of enuresis nocturna and only be used with caution.

Nocturnal enuresis

Nocturnal enuresis is common. Although its aetiology remains unclear recent evidence increasingly supports the lack of a normal nocturnal increase in ADH leading to nocturnal polyuria exceeding functional bladder capacity. Sleep patterns are probably normal although an arousal disorder might be a factor. Treatment should follow careful evaluation to determine if one is dealing with 'uncomplicated' or 'complicated' enuresis. Complicated enuresis requires further investigation. 'Uncomplicated enuresis' always requires reassurance and patient and parent education. Resource centres such as ERIC can provide information and advice. Active treatment should be tailored to the patients age, motivation and parental wishes. Behavioural modification techniques yield the highest long-term cure rate but require the most commitment and are rarely successful before the age of 7-8 years. Pharmacotherapy has been revolutionized by DDAVP which gives a response rate of up to 70% relatively free from side-effects but at the price of a high relapse rate after medication. Imipramine is less expensive than DDAVP but may be fatal in overdose. Anticholinergics should be reserved for those patients with significant diurnal symptoms or those who fail first-line pharmacotherapy. Overall patients and parents should be reassured by the high spontaneous cure rate.

Functional enuresis: is desmopressin the answer?

OBJECTIVE

The efficacy of desmopressin in the treatment of functional enuresis, known for 15 years, has received very little attention in the psychiatric literature. This review seeks to remedy this and to asses critically its effectiveness, risks and side effects, as well as the implications for the understanding and management of enuresis.

METHOD

Treatment trials, reports of unwanted effects, and literature on mechanisms of action were reviewed.

RESULTS

Desmopressin is more effective than placebo in controlled trials, but only one quarter of patients become "dry." Individuals who wet the bed 4 nights per week or more can expect a one-third reduction in their wet nights with a single intranasal dose of desmopressin before bedtime. Relapse rates upon cessation of treatment are very high, while side effects appear to be few. However, there are increasing reports of hyponatremic seizures. There is a group of patients in which bed-wetting appears to be the result of insufficient nocturnal secretion of vasopressin.

CONCLUSIONS

Desmopressin is a simple-to-use and effective drug for the treatment of nocturnal enuresis; it has opened important new avenues of inquiry, but more information is required about its long-term effectiveness and unwanted side effects.

Nocturnal enuresis

Nocturnal enuresis is a very common pediatric problem which often has strong genetic roots. In the vast majority of children it resolves spontaneously, with time, therefore research and treatment of bedwetting cannot carry any risk to the child. The research on the etiology of bedwetting has been focused on sleep disturbances, nocturnal urine production and functional bladder capacity. So far it has not provided conclusive evidence of the pathophysiology of the phenomenon. It is possible that different factors may be predominant in different age groups. Although bedwetters are basically mentally healthy, several studies have shown that the problem may cause secondary emotional and social problems which can be alleviated with successful intervention. Of the treatment modalities currently available to the pediatrician, the most effective is the moisture alarm. Combined with its safety and low cost it should become the treatment of choice in most cases.

Side effects and complications of treatment with desmopressin for enuresis

A literature search revealed 23 studies that have reported on the type or frequency of side effects or complications associated with the use of desmopressin (DDAVP, Rhône-Poulenc Rorer Pharmaceuticals Inc, Collegeville, Pennsylvania) for the treatment of enuresis. Thirty-one (4.3%) side effects were reported in 717 patients. Seizure secondary to water intoxication is a potential complication of treatment with desmopressin and was reported in six patients, usually in association with excess fluid intake during the evening or day preceding the use of desmopressin. Desmopressin appears to have a favorable safety profile. Patients should be specifically instructed not to ingest excess fluids during the evening prior to administration of desmopressin.

Efficacy, safety, and dosing of desmopressin for nocturnal enuresis in Europe

Desmopressin is a potent antidiuretic for nocturnal enuresis with few and mostly insignificant adverse reactions. Almost 80 years ago, the antidiuretic effects of extracts of the posterior pituitary were first reported. The molecular structure of the peptide vasopressin arginine vasopressin (AVP) became known in 1956, and by 1967, a synthesized modification of AVP, known as DDAVP, or desmopressin, was introduced. Toxicity studies performed on experimental animals support the conclusion that desmopressin is considerably more potent as an antidiuretic than AVP and has an exceptional safety margin. Further, clinical experience reveals that from 1974 to June 1992 only 21 patients using desmopressin had serious adverse reactions (water intoxication), and no fatalities occurred. Seven of 10 children with nocturnal enuresis who receive desmopressin stop their bedwetting completely or reduce it significantly, with best results noted in children over 10 years of age. Given these results, the preferred treatment in Europe for children with nocturnal enuresis is the sequential combination of desmopressin and the enuresis alarm.

The American experience with desmopressin

Conclusive evidence of a polyuric etiology from a failure of vasopressin elevation led to a new pharmacologic approach to the treatment of childhood nocturnal enuresis. Desmopressin acetate, a vasopressin analogue, has been used successfully since 1978 to treat this condition. Desmopressin's efficacy at doses of 5 to 40 micrograms has been demonstrated in Europe and the United States. Similarly, its safety has been established, and it is a first-line choice for physicians worldwide.

Drug therapy for nocturnal enuresis. Current treatment recommendations

It is estimated that enuresis occurs in 5 to 7 million children in the United States. The treatment approach for enuresis is controversial, in large part due to a lack of consensus as to the exact cause of enuresis. Several factors either alone or together may contribute to this syndrome. In addition, there is strong evidence of a genetic component to enuresis. Pharmacotherapy continues to be the preferred treatment for both physicians and families. The most widely used drugs include antidepressants, anticholinergics, and desmopressin. The tricyclic antidepressant imipramine has been used extensively since the 1960s. The exact mechanism of action in enuresis is unknown although it appears to be related to the anticholinergic and antispasmodic effects of the drug. The most common adverse effects reported with imipramine include personality changes, insomnia, anorexia and anxiety. There has been renewed interest in antidiuretic treatment of enuresis. Researchers have found that enuretic children do not have the ability to reduce urine volume at night or concentrate the urine they produce during the night. Clinical trials with desmopressin administered by nasal inhalation report a marked reduction in enuretic episodes. Adverse effects were limited to nasal complaints, rhinitis, or epistaxis. Additional long term studies are needed to delineate desmopressin's role in therapy. Although the number of options for treatment of enuresis is expanding, criteria to predict patient response need to be defined.

Low-dose DDAVP in nocturnal enuresis

A five-year experience with the vasopressin analogue desmopressin acetate (DDAVP) for nocturnal enuresis is described in 59 children. The initial starting dose of 5 micrograms at bedtime is lower than that reported in other series. Eighty-one percent of patients required 10 micrograms or less to achieve improvement or resolution of bedwetting.

Seizure with hyponatremia in a child prescribed desmopressin for nocturnal enuresis

We report a case of hyponatremia associated with a grand mal seizure in a 28 month-old child after intra-nasal desmopressin administration for high fluid intake with nocturnal enuresis. In view of the temporary symptomatic action and the seriousness of certain side-effects of desmopressin we recommend that desmopressin be used with caution in childhood enuresis.

Acute water intoxication after intranasal desmopressin in a patient with primary polydispsia

Only a few cases of severe acute water intoxication (AWI) due to intranasal desmopressin have been reported, none of which occurred in patients with primary polydipsia. We describe a case of AWI with semicoma and convulsions, due to intranasal desmopressin, in a 32-year-old patient with dipsogenic diabetes insipidus. Previous reported cases of AWI due to desmopressin are discussed. The importance of ruling out primary polydipsia when this drug is used, not only for central diabetes insipidus but also for other current indications such as classic hemophilia, is stressed.