Hyponatremia in patients with nocturnal enuresis treated with DDAVP

Management of the refractory nocturnal enuresis patient to desmopressin in a pediatric population: Desmopressin + oxybutynin vs. desmopressin + imipramine

INTRODUCTION AND OBJECTIVE

Desmopressin is well accepted as first-line medical therapy for enuresis. If ineffective, combination therapy of desmopressin + oxybutynin or desmopressin + imipramine has been used. This study assessed the efficacy of adjunct therapy with either imipramine or oxybutynin in the management of enuresis patients who failed desmopressin treatment.

STUDY DESIGN

A retrospective chart review of our database for patients with enuresis was performed. Patients who were prescribed desmopressin, oxybutynin, and imipramine over 14 years for enuresis were included. Two cohorts of patients were examined; group OXY was treated with desmopressin and oxybutynin, and group IMP received desmopressin and imipramine. Pretreatment measurement of Vancouver Symptom Scores (VSS) were used to compare groups using the VSS question "I wet my bed at night" where 4: every night, 3: 4-5 nights per week, 2: 1-2 nights per week, 1: 3-4 nights per month, and 0: never. International Children's Continence Society (ICCS) criteria for continence success was utilized to determine outcomes.

RESULTS

2521 patients prescribed one of the 3 medications were identified. Among them, 81 patients (mean age: 10.5 ± 2.8 years) received combination therapy. Of which, 55 were male and 26 female. Specifically, 58 were prescribed both desmopressin and imipramine (group IMP), 23 desmopressin and oxybutynin (group OXY), and 4 transitioned from OXY to IMP. Mean pretreatment VSS showed no difference between groups. Both groups experienced minimal drops in wet nights with desmopressin alone. A comparison revealed that group IMP reduced wet nights significantly more than group OXY (VSS wet night score 0.7 ± 1.2 vs. 2.3 ± 1.1 respectively, p < 0.0001). Non-intent-to-treat complete response rate was 68% vs 5% (OR = 42.5, p < 0.001) (IMP vs. OXY respectively). Intent-to-treat response rates were 58%.

DISCUSSION

Although first-line desmopressin treatment for enuresis is effective, it does not work for all patients, and many parents and children desire nighttime dryness. Clinicians have combined desmopressin with oxybutynin or imipramine for improved results, but research comparing these modalities is scarce. Our study suggests that the desmopressin and imipramine combination is superior at reducing nights wet compared to desmopressin and oxybutynin, attributed to imipramine's probable central mechanism rather than its secondary anticholinergic properties. Limitations include a modest sample size, retrospective design, and subjective responses to the Vancouver questionnaire.

CONCLUSION

A combination of desmopressin and imipramine was more effective in reducing wet nights and had a complete response rate that was 42.5 times greater than desmopressin and oxybutynin.

Desmopressin as a hemostatic and blood sparing agent in bleeding disorders

Intranasal, subcutaneous, or intravenous desmopressin can be utilized to release von Willebrand Factor and Factor VIII into circulation, enhance platelet adhesion and shorten bleeding time. Due to these properties, desmopressin can be effective in controlling bleeding in mild hemophilia A, certain subtypes of von Willebrand disease and in acute bleeding from uremia, end stage renal disease, and liver disease. Its use, however, can be complicated by hyponatremia and rarely arterial thrombotic events. While desmopressin has also been used as a prophylactic blood sparing agent in orthopedic, renal, and hepatic procedures, clinical studies have shown limited benefit in these settings. The purpose of this article is to review the evidence for desmopressin in primary hematologic disorders, discuss its mechanism of action and evaluate its utility as a hemostatic and blood sparing product in various bleeding conditions.

Timeline of Changes in Biomarkers Associated with Spinal Cord Injury-Induced Polyuria

Deficits in upper and lower urinary tract function, which include detrusor overactivity, urinary incontinence, detrusor-sphincter dyssynergia, and polyuria, are among the leading issues that arise after spinal cord injury (SCI) affecting quality of life. Given that overproduction of urine (polyuria) has been shown to be associated with an imbalance in key regulators of body fluid homeostasis, the current study examined the timing of changes in levels of various relevant hormones, peptides, receptors, and channels post-contusion injury in adult male Wistar rats. The results show significant up- or downregulation at various time points, beginning at 7 days post-injury, in levels of urinary atrial natriuretic peptide, serum arginine vasopressin (AVP), kidney natriuretic peptide receptor-A, kidney vasopressin-2 receptor, kidney aquaporin-2 channels, and kidney epithelial sodium channels (β- and γ-, but not α-, subunits). The number of AVP-labeled neurons in the hypothalamus (supraoptic and -chiasmatic, but not paraventricular, nuclei) was also significantly altered at one or more time points. These data show significant fluctuations in key biomarkers involved in body fluid homeostasis during the post-SCI secondary injury phase, suggesting that therapeutic interventions (e.g., desmopressin, a synthetic analogue of AVP) should be considered early post-SCI.

Effects of desmopressin acetate administration in healthy dogs receiving prednisolone

Background

Glucocorticoids are used for a variety of purposes in veterinary medicine but often are associated with clinically important adverse effects. Polyuria and polydipsia are the most frustrating adverse effects noted by owners.

Objective

To determine whether administration of desmopressin ameliorates polyuria and polydipsia associated with prednisolone administration.

Animals

Seven healthy adult Walker Hounds.

Methods

Prospective hypothesis testing study. Daily water intake and urine specific gravity (USG) were measured in dogs under 4 separate sequential conditions: no medications (C), prednisolone only (P), prednisolone and desmopressin (PD), and prednisolone after discontinuation of desmopressin (PAD).

Results

When compared to baseline, 6 of 7 dogs became polydipsic after administration of prednisolone (0.5 mg/kg PO q12h). When desmopressin (5 μg/dog SC q12h) was administered to dogs receiving prednisolone, significant decreases in water intake and serum sodium concentration occurred, and USG increased significantly.

Conclusions and Clinical Importance

Administration of desmopressin to dogs receiving prednisolone significantly decreased water intake and serum sodium concentration, and increased USG. Our results suggest that, in some dogs, desmopressin ameliorates the most important adverse effect of prednisolone noted by owners, but that hyponatremia is an important complication associated with desmopressin use.

Management and treatment of nocturnal enuresis-an updated standardization document from the International Children's Continence Society

BACKGROUND

Enuresis is an extremely common condition, which, although somatically benign, poses long-term psychosocial risks if untreated. There are still many misconceptions regarding the proper management of these children.

AIM

A cross-professional team of experts affiliated with the International Children's Continence Society (ICCS) undertook to update the previous guidelines for the evaluation and treatment of children with enuresis.

METHODS

The document used the globally accepted ICCS terminology. Evidence-based literature served as the basis, but in areas lacking in primary evidence, expert consensus was used. Before submission, a full draft was made available to all ICCS members for additional comments.

RESULTS

The enuretic child does, in the absence of certain warning signs (i.e., voiding difficulties, excessive thirst), not need blood tests, radiology or urodynamic assessment. Active therapy is recommended from the age of 6 years. The most important comorbid conditions to take into account are psychiatric disorders, constipation, urinary tract infections and snoring or sleep apneas. Constipation and daytime incontinence, if present, should be treated. In nonmonosymptomatic enuresis, it is recommended that basic advice regarding voiding and drinking habits be provided. In monosymptomatic enuresis, or if the above strategy did not make the child dry, the first-line treatment modalities are desmopressin or the enuresis alarm. If both these therapies fail alone or in combination, anticholinergic treatment is a possible next step. If the child is unresponsive to initial therapy, antidepressant treatment may be considered by the expert. Children with concomitant sleep disordered breathing may become dry if the airway obstruction is removed.

Desmopressin-Induced Severe Hyponatremia with Central Pontine Myelinolysis: A Case Report

Desmopressin, a synthetic vasopressin analog, is used to treat central diabetes insipidus, hemostatic disorders such as von Willebrand’s disease, and nocturnal enuresis. We present the case of a 69-year-old man who developed severe hyponatremia during treatment with intranasal desmopressin at 10 µg twice daily for chronic polyuria and nocturia thought to be due to central diabetes insipidus. After 5 months of therapy, the patient noticed progressive fatigue, anorexia, dizziness, weakness, light-headedness, decreased concentration, and new-onset falls. At 6 months of therapy, the patient was brought to the emergency department for altered mental status and was found to be severely hyponatremic with a serum sodium level of 96 mmol/L, down from a value of 134 mmol/L at the initiation of therapy. The intranasal desmopressin was discontinued and the patient was admitted to the intensive care unit where the hyponatremia was slowly corrected over the next week to 132 mmol/L, never increasing by more than 8 mmol/L a day, with careful fluid management. This included infusion of over 11 L of 5% dextrose to account for a high urine output, which peaked at 7.4 L in 1 day. However, while the recommended rate for sodium correction was followed, the patient’s magnetic resonance imaging of the brain obtained after discharge displayed evidence of central pontine myelinolysis. Despite this finding, the patient eventually returned to his baseline mental status with no permanent neurologic deficits.

Safety profile of desmopressin tablet for enuresis in a prospective study

INTRODUCTION

This pre-specified sub-study of the desmopressin response in primary nocturnal enuresis study (DRIP study) evaluates the safety profile of the oral desmopressin tablet in children with primary nocturnal enuresis. Endpoints are adverse events and change in body mass index.

METHODS

The DRIP study was an open-label, intention-to-treat, phase IV, multi-national study. Overall, 936 patients were screened and 744 children aged 5-15 years with previously untreated primary nocturnal enuresis were eligible to receive the study medication desmopressin once daily as an oral tablet formulation. At each visit, adverse events were questioned and observed signs or symptoms were recorded.

RESULTS

Overall, 222 (30%) patients experienced 404 treatment-emergent adverse events. The proportion of patients experiencing treatment-emergent adverse events was similar regardless of patient gender or age. Most treatment-emergent adverse events were experienced in three system organ classes: gastrointestinal disorders; infections and infestations; and respiratory, thoracic and mediastinal disorders and were considered unrelated to the study drug. There was a slight increase in body mass index from screening levels during the study, however, clinically not significant.

CONCLUSION

Desmopressin tablet treatment is well tolerated in children with primary nocturnal enuresis, regardless of patient gender or age.

FUNDING

The desmopressin response in primary nocturnal enuresis study (DRIP- study) was funded by Ferring.

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.

Efficacy of an enuresis alarm, desmopressin, and combination therapy in the treatment of saudi children with primary monosymptomatic nocturnal enuresis

Purpose

We evaluated and compared the effectiveness of an enuresis alarm, desmopressin medication, and their combination in the treatment of Saudi children with primary monosymptomatic nocturnal enuresis (PMNE).

Materials and Methods

A total of 136 children with PMNE were randomly assigned to receive an enuresis alarm alone (EA group, n=45), desmopressin alone (D group, n=46), or a combination of both (EA/D group, n=45). Patients were followed weekly during treatment and for 12 weeks after treatment withdrawal.

Results

During treatment, wetting frequencies were significantly reduced in all groups and remained significantly lower than pretreatment values until the end of follow-up. In the D and EA/D groups, an immediate reduction in wetting frequencies was observed, whereas a longer time was required to reach a significant reduction in the EA group. The full and partial response rates were 13.3% and 37.8% in the EA group, 26.1% and 43.5% in the D group, and 40.0% and 33.3% in the EA/D group. A significant difference was observed only between the EA and EA/D groups (p=0.025). Relapse rates were higher in the D group (66.6%) than in the EA (16.6%) and EA/D (33.3%) groups. A significant difference was observed between the D and EA groups only (p=0.019).

Conclusions

Desmopressin, an enuresis alarm, and combined therapy are effective in the treatment of Saudi children with PMNE. Desmopressin produced an immediate effect but relapses were common. The enuresis alarm provided gradual effects that persisted posttreatment. The combined therapy was superior to the alarm in achieving an immediate response; however, its effect was not better than that of the alarm long term.

Nocturnal enuresis-theoretic background and practical guidelines

Nocturnal polyuria, nocturnal detrusor overactivity and high arousal thresholds are central in the pathogenesis of enuresis. An underlying mechanism on the brainstem level is probably common to these mechanisms. Enuretic children have an increased risk for psychosocial comorbidity. The primary evaluation of the enuretic child is usually straightforward, with no radiology or invasive procedures required, and can be carried out by any adequately educated nurse or physician. The first-line treatment, once the few cases with underlying disorders, such as diabetes, kidney disease or urogenital malformations, have been ruled out, is the enuresis alarm, which has a definite curative potential but requires much work and motivation. For families not able to comply with the alarm, desmopressin should be the treatment of choice. In therapy-resistant cases, occult constipation needs to be ruled out, and then anticholinergic treatment-often combined with desmopressin-can be tried. In situations when all other treatments have failed, imipramine treatment is warranted, provided the cardiac risks are taken into account.

Perioperative incidence and management of hyponatremia in vWD patients undergoing adenotonsillectomy

OBJECTIVES/HYPOTHESIS

To analyze the incidence and severity of hyponatremia in patients receiving synthetic desmopressin (DDAVP) in the perioperative setting of oropharyngeal surgery in the treatment of von Willebrand disease and to propose a standardized protocol for perioperative fluid resuscitation and postoperative sodium monitoring after DDAVP administration.

STUDY DESIGN

Retrospective medical record review.

METHODS

A retrospective medical record review in an academic pediatric medical center was conducted. From October 1, 2002, to February 1, 2009, all patients undergoing adenotonsillectomy and receiving DDAVP preoperatively for the treatment of von Willebrand disease were identified. A total of 76 patients were identified by initial database review; 63 patients were included in the study, and 13 patients were excluded secondary to incomplete data. DDAVP dose and timing, perioperative fluid volume and composition, and postoperative sodium levels were collected. Extreme adverse events related to hyponatremia were recorded.

RESULTS

Forty-seven of 63 (74.6%) patients developed some degree of hyponatremia after DDAVP administration, and six of 63 (9.5%) patients developed extreme hyponatremia, with the degree of hyponatremia related to the volume of perioperative fluid resuscitation. The sodium nadir occurred within 9 to 20 hours after DDAVP administration. No serious adverse events related to hyponatremia were recorded during the study period.

CONCLUSIONS

The incidence of hyponatremia in children receiving DDAVP for prophylaxis of intraoperative bleeding following oropharyngeal surgery is high. The degree of hyponatremia is related to the perioperative fluid volume administered. A protocol for DDAVP administration, perioperative fluid resuscitation, and postoperative sodium monitoring that aims to reduce the incidence of hyponatremia in this population is proposed.

Treatment options for parasomnias

Parasomnias are undesirable physical or experiential events that occur in and around sleep. Treatments include reassurance in some cases, various forms of cognitive-behavioral therapy (CBT), and pharmacologic agents. Cognitive restructuring, imagery rehearsal, relaxation, hypnosis, desensitization, and anticipatory awakenings are some of the common CBT and nonpharmacologic interventions. Medications that are used belong to a wide variety of pharmacologic classes, such as alpha-blockers (prazosin), tricyclic antidepressants (imipramine and clomipramine), selective serotonin reuptake inhibitors, benzodiazepines (diazepam and clonazepam), anticonvulsants (topiramate and gabapentin), desmopressin acetate, and anticholinergic agents (oxybutynin and tolterodine). Data on efficacy are only available from randomized trials on CBT and prazosin for nightmares and on pharmacologic and alarm therapy for enuresis. No large-scale randomized trials are available to assess the efficacy of the other treatments, and most data come from anecdotal case reports, case series, or small open-label trials.

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.

Primary monosymptomatic nocturnal enuresis in children and adolescents

Nocturnal enuresis (NE) is one of the most frequent paediatric pathologies. The prevalence of primary nocturnal enuresis (PNE) is around 9% in children between 5 and 10 years of age and about 40% of them have one or more episodes per week. Still for too long, PNE has not been recognised as a pathological condition, particularly by the medical community; as a consequence, there was no specific education at medical school, and a poor involvement by the practitioners. Enuretic children have a sense of social difference and isolation; some of them do express a low self-esteem. Also, self-esteem is improved by the management NE even if this management fails to cure the condition. Primary monosymptomatic nocturnal enuresis (PMNE) is an heterogeneous condition for which various causative factors have been identified such as: nocturnal polyuria, sleep disturbances, reduced bladder capacity or bladder dysfunction, upper airway obstruction. The positive diagnosis of PMNE is based on a complete questionnaire and a careful physical examination. A drinking and voiding chart is an essential non-invasive tool: first, to collect information about the initial drinking and voiding habits of the child, then to reassess the accuracy of the diagnosis. Only motivated patients should receive a specific treatment for their NE and the treatment should be proposed based on the type of PMNE. PMNE associated with nocturnal polyuria should be treated with desmopressin, which reduces nighttime urine production. For PMNE with a reduced bladder capacity alarms should be the first-line treatment. Oxybutinin, a drug with anticholinergic properties, is not theoretically indicated for the treatment of PMNE except for a very small subgroup of patients who have an overactive bladder only during sleep. In cases refractory to monotherapy, NE is probably the result of an association of different physiopathological factors (e.g. both a nocturnal polyuria together with a small bladder capacity) some of them are still unknown. In these patients, a combination of treatments may be more effective than monotherapy. Various combination therapies can be proposed to improve the cure rates.

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.

Antidiuresis therapy: Mechanism of action and clinical implications

Abnormalities of micturition occur in many different diseases, have a variety of causes and take several forms. This review will focus exclusively on those abnormalities in which antidiuretic therapy may be of benefit. These conditions are primarily characterized by an increase in the total amount of urine produced (polyuria) or a circadian shift in the control of urine production and/or voiding (nocturnal enuresis, nocturia).

Desmopressin acetate for enuresis and diabetes insipidus

Desmopressin is a synthetic agonist of the natural pituitary hormone vasopressin acetate, with enhanced antidiuretic properties. In fact, owing to its selectivity for the V2 receptor, it has a greater antidiuretic activity, but lower pressure effects compared with natural antidiuretic hormone. Desmopressin is used in the diagnosis and treatment of cranial diabetes insipidus, in the treatment of monosymptomatic enuresis and for tests of renal function.

Desmopressin Toxicity Due to Prolonged Half-Life in 18 Patients With Nocturnal Enuresis

PURPOSE

Desmopressin has been used extensively for primary nocturnal enuresis and it is associated with a low incidence of adverse effects. The only reported serious side effect is seizure or altered levels of consciousness resulting from water intoxication, which has been reported for the nasal spray. We describe 18 children with clinical symptoms of water intoxication due to the prolonged bioactivity of desmopressin nasal spray.

MATERIALS AND METHODS

We evaluated 18 patients with clinical suspicion of prolonged desmopressin bioactivity during treatment with intranasal desmopressin for primary nocturnal enuresis. The control group consisted of 50 children with primary nocturnal enuresis and proven nocturnal polyuria who were treated with the same desmopressin regimen.

RESULTS

All patients had prolonged maximal urinary concentration capacity and delayed restoration of daytime diluting capacity (p <0.01). Of the patients 15 had the characteristic clinical symptoms of water intoxication with vomiting, headache, decreased consciousness and hyponatremia. We suspect that these symptoms are secondary to prolonged desmopressin bioactivity.

CONCLUSIONS

Prolonged desmopressin bioactivity may increase the risk of water intoxication.

Rôle du médecin traitant dans les convulsions hyponatrémiques chez l'enfant énurétique traité par desmopressine

Enuresis nocturna is regularly treated by desmopressin, a vasopressin analog. Its side effects, notably neurological, are fortunately rare. We comment on 5 enuretic children on desmopressin who suffered from hyponatremic encephalopathy (natremia 115-127, median 117 mmol/l).

RESULTS

Side effects appeared at therapeutic doses (10-40 mg/d intranasal). An excessive fluid intake at night was often noted, leading to a dilutional hyponatremia. This may be due to a lack of correct information to the parents. These children presented after a period of warning symptoms, such as headache, vomiting and altered consciousness. Parents could have sought earlier medical attention if they had been informed about these symptoms.

CONCLUSION

In the absence of fluid restriction, severe hyponatremia can occur in enuretic children on desmopressin. It is therefore mandatory for the prescribing doctor to adequately inform patients and parents to limit fluids at night when desmopressin is used, and seek medical help quickly if any sign of intracranial hypertension appears.

Desmopressin associated symptomatic hyponatremic hypervolemia in children. Are there predictive factors?

PURPOSE

Desmopressin is widely used in primary nocturnal enuresis, bleeding disorders, central diabetes insipidus and diagnostic urine concentration testing. Hyponatremic hypervolemia leading to seizures has been reported as a rare but potentially life threatening side effect of desmopressin therapy. We sought to identify factors that predispose patients to hyponatremia and to find predictive factors associated with increased risk of water intoxication.

MATERIALS AND METHODS

We report 13 novel cases of desmopressin associated water intoxication and review the literature. A total of 93 instances of symptomatic hyponatremia during desmopressin treatment in children were identified. Specific data were reported in 58 of 93 cases. These 58 cases, in addition to our 13 novel cases, were further analyzed.

RESULTS

All children were treated with intranasal or intravenous desmopressin. No patient received oral desmopressin. Younger children are at greater risk for water intoxication than older children. The risk is particularly high at the beginning of desmopressin therapy. A total of 45 patients (63%) had prodromal symptoms, eg nausea, vomiting and headache. In 10 cases (14%) desmopressin was prescribed without an evident need.

CONCLUSIONS

Based on this analysis, we conclude that the use of desmopressin should be cautiously considered, careful monitoring should be performed during the initiation of therapy, and particular care should be taken when treating young children and when prodromal symptoms such as nausea, vomiting and headaches occur.

DDAVP-induced hyponatremia in young children

Desmopressin (DDAVP) is used to improve hemostasis in patients with bleeding disorders. The side effects of DDAVP in adults and children are benign. However, there has been concern regarding the development of hyponatremia and seizures after the use of DDAVP in young children. The authors describe three children under 3 years of age who developed hyponatremia (two also developed seizures) following intravenous administration of DDAVP at a standard dose of 0.3 mug/kg. Fluid restriction, avoidance of hypo-osmolar fluid, and close monitoring of fluid and electrolytes for 12 to 24 hours after the administration of DDAVP in children younger than 3 years of age is recommended.

Hyponatremia in elderly patients treated with desmopressin for nocturia: a review of a case series

OBJECTIVE

Lately, desmopressin (dDAVP) administered orally has been demonstrated to be an effective alternative in the management of nocturia in adults. Although the safety profile of dDAVP is well known, much of the experience originates from studies in enuretic children and younger adults, and it may not be readily extrapolated to elderly patients. In order to identify factors associated with an increased risk of hyponatremia in elderly patients treated with dDAVP for nocturia, we analysed spontaneous reports accrued from clinical practice in Denmark and Sweden.

METHOD

Following a selection procedure, the study base comprised 15 case reports. From the included reports, information was sought on concurrent diseases, concomitant medications and other factors that may predispose elderly patients to hyponatremia when treated with desmopressin.

RESULTS

The median age amongst the cases was 81 years (range 61-93 years) and 80% were females. For seven of the patients, the hyponatremia occurred during the first 3 weeks of treatment. The symptoms presented by the patients led to hospitalisation in all but one case. Among patients with information available on concomitant medication, half of them were treated with cyclooxygenase inhibitors. An excessive fluid intake could only be ascertained in one case; all 15 patients eventually recovered.

CONCLUSION

In elderly patients treated with dDAVP for nocturia, an increased risk of hyponatremia exists in the first weeks of treatment. Compared with younger subjects, risk factors other than excessive intake of fluid appear to contribute to this adverse drug reaction.

A pharmacokinetic and pharmacodynamic study of desmopressin: evaluating sex differences and the effect of pre-treatment with piroxicam, and further validation of an indirect response model

Desmopressin is a synthetic vasopressin analogue mainly used in treatment of diabetes insipidus and nocturia. Studies in rats have revealed a sex difference in the response to a vasopressin infusion, which was diminished after treatment with an NSAID. This study was performed in man to investigate the influence of sex and concomitant treatment of piroxicam on the pharmacokinetics and dynamics of desmopressin, and to validate a previously described indirect response model. Eight healthy males and eight healthy females participated in the trial, which was conducted in a pharmacokinetic (PK) part followed by a pharmacodynamic (PD) part. Desmopressin was administered intravenously as a single dose (PK = dose 2 microg, PD = dose 0.2 microg). Piroxicam was administered to achieve steady state. The pharmacokinetic parameters of desmopressin were estimated and calculated by means of two-compartmental analysis. In the dynamic part a study design based on an oral hydration model was used. Parameters for urine flow and urine osmolality were estimated. Individual estimates of the pharmacokinetic parameters served as input to the indirect response model that subsequently was fitted to urine osmolality data. The pharmacokinetics of desmopressin after a fixed bolus injection was neither influenced by piroxicam nor sex of the subject. The pharmacodynamics of desmopressin showed a sex difference where females exhibited a more pronounced antidiuretic effect than males, which was statistically significant when the effects were submaximal (>4.5 h after dose). The sex differences were diminished after pre-treatment with piroxicam, indicating a prostaglandin PGE(2)-mediated mechanism. The indirect response model was confirmed, although the modelling could not distinguish a sex difference, indicating a limitation of this model compared with traditional descriptive statistics.

Nocturnal enuresis: medical management

Nocturnal enuresis is a problem that affects many children and their families. The etiology seems to be multifactorial and may include a combination of genetic factors,abnormal urodynamics, alterations in vasopressin secretion, sleep factors, psychologic factors, organic disease, and maturational delay. Generally, a complete history and physical examination, with a specific focus on the genitourinary, gastrointestinal, and neurologic systems, is all is that is needed in the evaluation of a patient with enuresis.Currently, the mainstays of medical therapy are DDAVP, imipramine, and oxybutynin. Medications can help to control the symptoms of enuresis, but they generally do not provide a cure; therefore, behavioral therapy is often recommended in conjunction with pharmacotherapy.

Antidiuresis: a new concept in managing female daytime urinary incontinence

OBJECTIVE

To investigate the efficacy of desmopressin nasal spray on daytime urinary incontinence in women.

PATIENTS AND METHODS

A multicentre, multinational, randomized, double-blind, placebo-controlled, cross-over exploratory study of women (aged 18-80 years) complaining of severe daytime urinary incontinence was conducted in three centres (King's College Hospital; Boras County Hospital and Skejby Hospital). Seventy-five patients were screened of whom 64 were randomized. In all, 60 women received study medication (safety population) and 57 completed the study. The intention-to-treat population comprised 59 patients and there were 41 in the per protocol analysis. The primary efficacy endpoint was the number of periods with no leakage for 4 h after dosing. Women were instructed to take the drug at a time of their choosing, but >/= 4 h before bedtime. Secondary efficacy variables included the time to first void or incontinence episode, volume leaked per incontinence episode, total volume voided and number of periods with no leakage. All measurements were made over 7 days on desmopressin and 3 days on placebo.

RESULTS

There was a higher mean (sd) incidence of periods with no leakage in the first 4 h on desmopressin, at 62 (35)%, than on placebo, at 48 (40)%, and during the first 8 h, at 55 (37)% vs 40 (41)%. There was also a higher frequency of dry days on desmopressin than on placebo; 36% of patients had no leakage on virtually all treatment days (6 or 7) for 4 h after dosing. At 4-8 h the incidence of periods with no leakage on desmopressin was 68 (35)% vs 63 (41)% on placebo, and thereafter the incidence was similar. The time from dosing to first incontinence episode was longer on desmopressin, at 6.3 (2.5) h, vs 5.2 (3.3) h, whilst the volume leaked per incontinence episode was lower on desmopressin than placebo. The total volume voided was consistently lower on desmopressin, at 1180 (58) mL vs 1375 (57) mL, over the 24-h period after administration. There were no serious or severe adverse events reported. Seven women (11%) withdrew from the study, of whom five did not attend for the final visit and two (3%) because of mild adverse events.

CONCLUSIONS

The results of this exploratory study suggest that desmopressin is an effective and safe treatment in women with daytime urinary incontinence, and allows them to choose when they need treatment, thus improving motivation, which may aid compliance with therapy.

Causes and management of hyponatremia

OBJECTIVE

To review clinical information on the incidence and causes of hyponatremia (defined as a serum sodium level <130 mEq/L), the most common electrolyte abnormality seen in general hospital patients, and to discuss the diagnosis and treatment of hyponatremia in relation to these factors.

DATA SOURCES

Primary sources and review articles were identified via MEDLINE (1981-July 2003) for entries on hyponatremia. We limited the search to specific topics including incidence, risk factors, diagnosis, treatment, and clinical disorders and medications associated with hypotonic hyponatremia.

STUDY SELECTION AND DATA EXTRACTION

All of the articles identified were evaluated, and relevant and representative information was included in this review.

DATA SYNTHESIS

Hyponatremia can result from several disease states, injury, surgery, physical exercise, or the administration of certain drugs (e.g., antidepressants, antiepileptics) and is associated with advanced age. Drug-induced hyponatremia is often asymptomatic and usually resolves following water restriction and monitoring of medication. Symptoms of hyponatremia are primarily neurologic; the principal danger of hyponatremia relates to effects on central nervous system function due to changes in brain size.

CONCLUSIONS

Although hyponatremia can be a serious condition, appropriate measures for the management of at-risk and affected patients will lead to full recovery in most cases.

Sleep disordered breathing and nocturnal polyuria: nocturia and enuresis

Although nocturnal voiding is frequently attributed to urologic disorders, nocturia and enuresis are also important symptoms of sleep-disordered breathing. However, polyuria can be elicited by obstructive sleep apnea as well as bedrest, microgravity and other experimental conditions where the blood volume is shifted centrally to the upper body. The nocturnal polyuria of sleep apnea is an evoked response to conditions of negative intrathoracic pressure due to inspiratory effort posed against a closed airway. The mechanism for this natriuretic response is the release of atrial natriuretic peptide due to cardiac distension caused by the negative pressure environment. This cardiac hormone increases sodium and water excretion and also inhibits other hormone systems that regulate fluid volume, vasopressin and the rennin-angiotensin-aldosterone complex. Treatment of sleep apnea and airway compromise has been shown to reverse nocturnal polyuria and thereby reduce or eliminate nocturia and enuresis. Thus, careful evaluation of nocturia and enuresis for evidence of nocturnal polyuria can increase the diagnostic certainty of referring primary care providers and sleep specialists. In addition, the resolution of these bothersome symptoms after treatment can contribute to patient satisfaction as well as reinforce treatment compliance.

An overview of the management of nocturnal enuresis in children

Nocturnal enuresis is one of the common conditions of childhood and left untreated can cause increasing stress and anxiety for the child and disruption for the family. This article gives an overview of the potential contributory factors to the cause of bedwetting and highlights the importance of carrying out a focused assessment using the 'three systems' approach, to not only exclude any underlying pathology but also help direct treatment. The different treatment options are discussed and emphasis is placed on involving the child and family in the decision-making process. A child-focused approach will help ensure that whatever treatment is chosen, either the alarm or desmopressin will lead towards the best treatment outcome.

Autonomic Nervous System Dysfunction in Parkinson's Disease

Autonomic nervous system (ANS) dysfunction is common in Parkinson's disease (PD), affects 70% to 80% of patients, and causes significant morbidity and discomfort. Autonomic nervous system dysfunction symptoms in PD include sexual dysfunction, swallowing and gastrointestinal disorders, bowel and bladder abnormalities, sleep disturbances, and derangements of cardiovascular regulation, particularly, orthostatic hypotension. Autonomic nervous system dysfunction in PD may be caused by an underlying degenerative process that affects the autonomic ganglia, brainstem nuclei, and hypothalamic nuclei. Anti-parkinsonian medications can cause or worsen symptoms of ANS dysfunction. The care of a PD patient with ANS dysfunction relies on its recognition and directed treatment, including coordinated care between the neurologist and appropriate subspecialist. Pharmacotherapy may be useful to treat orthostasis, gastrointestinal, urinary, and sexual dysfunction.

Evaluation of high concentration intranasal and intravenous desmopressin in pediatric patients with mild hemophilia A or mild-to-moderate type 1 von Willebrand disease

OBJECTIVES

The objective of the study was to evaluate the safety and efficacy of high-concentration intranasal desmopressin (HCIN-DDAVP) 1.5 mg/mL, in patients weighing < or = 50 kg with mild hemophilia A or mild type 1 von Willebrand disease (VWD).

STUDY DESIGN

This was a single-center, nonrandomized, open-label, single-dose trial of HCIN-DDAVP. Nine boys with hemophilia A, 8 girls with mild VWD, and 8 boys with mild VWD were evaluated. HCIN-DDAVP responses were compared with historic IV-DDAVP responses in 13 of the patients.

RESULTS

HCIN-DDAVP administration resulted in statistically significant mean increases in factor VIII procoagulant activity, ristocetin cofactor, and von Willebrand factor antigen levels in each of the 3 study groups. Mean (+/- 1 SD) increase in factor VIII procoagulant activity was 25.7 +/- 11.9 U/dL in mild hemophilia A. Ristocetin cofactor increased 108.5 +/- 53.8 U/dL in girls and 95.8 +/- 36.0 U/dL in boys with mild VWD. Intravenous desmopressin acetate responses were comparable to HCIN-DDAVP responses in patients who received both preparations. Adverse events were mild and resolved without intervention.

CONCLUSION

We conclude that administration of 150 microg of high concentration intranasal desmopressin is safe and effective in patients weighing < or = 50 kg with mild hemophilia A or mild type 1 VWD.

Enuresis and encopresis: ten years of progress

OBJECTIVE

To review the progress made over the past decade with regard to the treatment of enuresis and encopresis, as well as advances in the understanding of etiological mechanisms.

METHOD

Separate computerized literature (English language only) searches of Medline and PsycINFO databases were conducted under the parameter of enuresis and children-adolescents, as well as encopresis and children-adolescents.

RESULTS

There has been a substantial decrease in published research concerning the use of imipramine to treat enuresis compared with the prior two decades, accompanied by a corresponding increase in the number of papers concerning desmopressin acetate (DDAVP), which has become the primary pharmacological treatment. Genetic studies of large pedigrees have further confirmed the importance of heritable factors. With regard to encopresis, the research has focused primarily on pathophysiological factors related to the colon and anal sphincter.

CONCLUSIONS

The widespread use of DDAVP has been the primary addition to treatment strategies over the past decade. The bell-and-pad method of conditioning, the only major treatment that has enduring benefit after being withdrawn, is the most cost-effective and appears to be underutilized. Research into etiological mechanisms has focused primarily on the mechanism of action of DDAVP and advances in the understanding of genetic factors. Advances in the treatment and etiological understanding of encopresis have been less impressive.

Secondary nocturnal enuresis

Secondary nocturnal enuresis accounts for about one quarter of patients with bed-wetting. Although a psychological cause is responsible in some children, various other causes are possible and should be considered. This article reviews the epidemiology, psychological and social impact, causes, investigation, management, and prognosis of secondary nocturnal enuresis.

Drug therapy for urinary incontinence

Drugs used for treatment of urinary incontinence may act on the central nervous system (CNS) or peripherally. Few drugs with a defined CNS site of action are available for treatment of urine storage disorders; most of those currently used have a peripheral site of action. To treat bladder overactivity associated with urgency and urge incontinence, antimuscarinic drugs, alpha-adrenoceptor antagonists, beta-adrenoceptor agonists, prostaglandin synthesis inhibitors, and several other agents most often developed for non-urological indications, are employed. Current treatment is based on the use of antimuscarinic drugs, and oxybutynin is, despite a high incidence of side-effects, the gold standard. Pharmacological treatment of stress incontinence has had limited success, and only alpha-adrenoceptor agonists, with and without combination with oestrogens have had a documented effect. New drugs, specifically directed at treatment of urine storage disorders, are desirable.

Relation of nocturnal polyuria of the elderly to essential hypertension

Nocturnal polyuria is common in the elderly. In this condition the normal circadian rhythm of urine production is reversed so that urine flow is higher at night than during the day. Elderly men with nocturnal polyuria are commonly referred for prostate surgery, which, not surprisingly, fails to relieve their symptoms. Compared with controls, patients with nocturnal polyuria have higher nocturnal sodium excretion but not higher nocturnal free-water clearance. Similar results have been obtained in children with nocturnal enuresis. Use of vasopressin analogues to induce water retention in elderly patients with nocturnal polyuria is illogical and potentially hazardous; nocturia can be more safely alleviated by diuretic therapy. Nocturnal polyuria in the elderly is associated with hypertension: this is consistent with studies in younger age groups that show that essential hypertension is associated with nocturia and with increased night/day ratios for sodium excretion. We propose that nocturnal polyuria and essential hypertension share some of the same pathophysiological determinants. Specifically, we suggest that a defect in the nitric-oxide pathway may lead to resetting of the pressure-natriuresis relation in the kidney, sodium retention, and compensatory nocturnal natriuresis. This suggestion is consistent with evidence that ageing and essential hypertension are both associated with defects in the nitric-oxide pathway. Our hypothesis has obvious therapeutic implications. More generally, studying the pathogenesis of nocturnal polyuria in the elderly may advance our understanding of the pathogenesis of essential hypertension.