Treatment of primary monosymptomatic nocturnal enuresis with desmopressin: predictive factors

Evaluation of Functional Bladder Capacity in Children with Nocturnal Enuresis According to Type and Treatment Outcome

Purpose

This study aimed to identify whether functional bladder capacity (FBC) differs among subgroups of nocturnal enuresis (NE) patients and can be used to predict treatment response.

Methods

A total of 69 children with NE were included in this study between July 2017 and February 2019 according to medical chart review, retrospectively. All patients completed a questionnaire about voiding symptoms and 48-hour frequency/volume (48-h F/V) charts. FBC was obtained from the 48-h F/V charts and uroflowmetry (UFM) with post-void residual volume (PVR). All patients were primarily treated with standard urotherapy and pharmacological therapy. The response rate was analyzed at 3 months after treatment.

Results

The mean age of the 69 patients (42 male, 27 female) was 83.3 ± 22.4 months (range, 5–13 years) at the first visit. The percentages of children with monosymptomatic NE (MNE) and non-monosymptomatic NE (NMNE) on the questionnaire were 40.6% (28/69) and 59.4% (41/69), respectively. FBC of all patients was lower than the normal range of expected bladder capacity, and there were no significant differences between measurement methods, NE types (MNE vs NMNE), or response rates (p > 0.05).

Conclusion

Children with NE had diminished FBC in both 48-h F/V charts and UFM with PVR. We found no difference in FBC by NE type or treatment outcome. Therefore, FBC cannot be used to distinguish between NE types or predict treatment responses.

Pediatric Pharmacology of Desmopressin in Children with Enuresis: A Comprehensive Review

Desmopressin is a synthetic analogue of the natural antidiuretic hormone arginine vasopressin. Over the years, it has been clinically used to manage nocturnal polyuria in children with enuresis. Various pharmaceutical formulations of desmopressin have been commercialized for this indication-nasal spray, nasal drops, oral tablet and oral lyophilizate. Despite the fact that desmopressin is a frequently prescribed drug in children, its use and posology is based on limited pediatric data. This review provides an overview of the current pediatric pharmacological data related to the different desmopressin formulations, including their pharmacokinetics, pharmacodynamics and adverse events. Regarding the pharmacokinetics, a profound food effect on the oral bioavailability was demonstrated as well as different plasma concentration-time profiles (double absorption peak) of the desmopressin lyophilizate between adults and children. Literature about maturational differences in distribution, metabolism and excretion of desmopressin is rather limited. Regarding the pharmacodynamics, formulation/dose/food effect and predictors of response were evaluated. The lyophilizate is the preferred formulation, but the claimed bioequivalence in adults (200 µg tablet and 120 µg lyophilizate), could not be readily extrapolated to children. Prescribing the standard flat-dose regimen to the entire pediatric population might be insufficient to attain response to desmopressin treatment, whereby dosing schemes based on age and weight were proposed. Moreover, response to desmopressin is variable, whereby complete-, partial- and non-responders are reported. Different reasons were enumerated that might explain the difference in response rate to desmopressin observed: different pathophysiological mechanisms, bladder capacity and other predictive factors (i.e. breast feeding, familial history, compliance, sex, etc.). Also, the relapse rate of desmopressin treatment was high, rendering it necessary to use a pragmatic approach for the treatment of enuresis, whereby careful consideration of the position of desmopressin within this treatment is required. Regarding the safety of the different desmopressin formulations, the use of desmopressin was generally considered safe, but additional measures should be taken to prevent severe hyponatremia. To conclude the review, to date, major knowledge gaps in pediatric pharmacological aspects of the different desmopressin formulations still remain. Additional information should be collected about the clinical relevance of the double absorption peak, the food effect, the bioequivalence/therapeutic equivalence, the pediatric adapted dosing regimens, the study endpoints and the difference between performing studies at daytime or at nighttime. To fill in these gaps, additional well designed pharmacokinetic and pharmacodynamic studies in children should be performed.

Does smoking exposure affect response to treatment in children with primary monosymptomatic nocturnal enuresis?

BACKGROUND

There are many variables affecting the success of treatment in children with primary monosymptomatic nocturnal enuresis (PMNE). This study investigates the possible effect of cigarette smoke exposure on desmopressin treatment response in children with PMNE.

METHOD

The medical records of pediatric patients with PMNE between February 2018 and December 2018 were retrospectively reviewed. Those who had moderate (3-5 wet nights/week) and severe (>5 wet nights/week) PMNE were included in the study. All patients received 120 mcg of sublingual desmopressin. After 3 months of therapy, treatment response was classified as complete response (100% dry night), partial response (between 50% and 99%) and non-responsiveness (<49% improvement). Partial response or non-responsiveness is considered as treatment failure. The relationship between treatment response to desmopressin and exposure to cigarette smoke was evaluated. Moreover, the other risk factors for treatment failure were investigated.

RESULTS

A total of 81 children with the diagnosis of PMNE, with a mean age of 9.98 ± 2.62 years, were included in the study. The frequency of passive smoke exposure at home was 53.1%. Sixty-two patients (76.5%) had severe PMNE, and the response to desmopressin decreased with severity of symptoms. Non-responsiveness to treatment, partial response, and complete response were observed in 11 (13.6%), 23 (28.4%), and 47 (58.0%) of patients, respectively. Treatment failure (n = 34, 42%) was 55.8% in children exposed to smoke and 26.4% in those who were not (p = 0.001). Although univariate analysis revealed that the severity of symptoms and smoke exposure were associated with treatment failure, in multivariate analysis, the presence of smoke exposure was the only independent risk factor (OR = 3.214, 95% CI: 0.125-0.888; p = 0.024) (Summary Table 1).

CONCLUSION

Exposure to cigarette smoke is a changeable and important risk factor that reduces the success of desmopressin treatment in children with PMNE.

Exploration of the Optimal Desmopressin Treatment in Children With Monosymptomatic Nocturnal Enuresis: Evidence From a Chinese Cohort

Objectives: Nocturnal enuresis (NE) is a common pediatric condition, and desmopressin (dDAVP) is a first-line therapy for NE. The standard initial dosage of dDAVP is 0. 2 mg/day, and most guidelines recommend that the dose should be increased at 0.2 mg increments until dryness is achieved or to the maximal recommended dose. However, previous evidence has shown that this strategy seems insufficient to further improve efficacy and results in unnecessarily high doses for some patients. Our study aimed to assess the efficacy of our modified dDAVP treatment regimen in children with MNE in China and evaluate predictive factors associated with the dDAVP response. Methods: All MNE patients at the Department of Nephrology at Children's Hospital of Fudan University from January to December 2019 were prospectively and consecutively enrolled. dDAVP treatment comprised a dose titration period and a 3-month maintenance period. The efficacy of dDAVP was assessed according to the latest International Children's Continence Society criteria at the end of the study. Predictive factors were evaluated by logistic regression analysis. Results: Overall, 322 MNE patients were enrolled in our study, and 225 (69.9%) completed the study. The intention to treat analysis showed that the overall dDAVP response rate was 69.9%: among these patients 32.3% were complete responders, and 37.6% were partial responders. At the end of the study, 194/225 (86.2%) patients received a final dose of 0.2 mg, 24/225 (10.7%) patients received a final dose of 0.3 mg, and 7/225 (3.1%) patients received a final dose of 0.4 mg. Multivariate analysis showed that patients requiring lower doses to achieve responses were significantly more likely to experience complete response during the maintenance period [odds ratio (OR)=9.683; 95% confidence interval (CI), 2.770-33.846]. Conclusions: Our results indicate that the dDAVP treatment regimen provides a comparable efficacy to the international conventional treatment regimen with a lower overall dose. Low-dose responders were likely to achieve a complete response without increasing the dose; in these cases, the maximum dose might not be necessary.

Infrequent enuresis, the uninvestigated majority comparisons between children with enuresis of varying severity

OBJECTIVE

The main objective was to compare children with frequent enuresis (FE) and children with infrequent enuresis (IE) using anamnestic data and variables related to bladder and kidney function. A secondary aim was to look at the group of children who wet their beds every single night, a phenomenon we chose to call constant enuresis (CE).

SUBJECTS AND METHODS

The parents recorded the number of wet and dry nights for a period of 14 days, and measured the voided volumes as well as nocturnal urine production for 48 h. History data relevant to bladder and bowel function was also recorded.

RESULTS

The children could be grouped as follows: IE, n = 14; FE, n = 18; and CE, n = 22. The children with IE were slightly older than the other groups, IE mean 7.57; FE mean 6.22; CE, mean 6.56 (p = 0.004). When comparing the groups in terms of the measured parameters, only one significant difference was found: the FE group had larger average daytime voided volumes, but only when the first morning void was included. The only significantly differing anamnestic variable was previous daytime incontinence, which was more common among the children in the IE group.

CONCLUSIONS

When comparing children with varying enuresis severity, no major differences regarding bladder function and urine production were found. Furthermore, children with infrequent enuresis tend to be slightly older when they seek medical help.

Long-term desmopressin response in primary nocturnal enuresis: open-label, multinational study

BACKGROUND

Primary nocturnal enuresis (PNE) is a distressing condition, particularly in severe cases (> or = 3 wet nights/week). A prevalent pathophysiological mechanism, especially in monosymptomatic PNE (PMNE), is commonly believed to be an insufficient increase in night-time release of antidiuretic hormone. Desmopressin, a synthetic analogue of antidiuretic hormone, has been shown to reduce the number of wet nights experienced by PMNE patients in several controlled trials.

AIM

This study was performed to evaluate desmopressin treatment in the real-life clinical setting and was a large-scale, 6-month investigation of efficacy and safety in patients with severe PNE. Predictive factors for desmopressin response were also evaluated. A total of 744 children aged 5 years and above from four countries were involved in the study.

RESULTS

At baseline, patients had a median of 6 wet nights/week; at 6 months, 41% of patients had experienced > or = 50% reduction in the mean number of wet nights. Long-term desmopressin treatment was consistently well-tolerated across all ages, with 5% of patients experiencing any treatment-related adverse events. The strength of treatment response was associated with nocturnal diuresis (p < 0.0001) and age (p = 0.0167) in logistic regression analyses. Compliance and dosage were also associated with response and more patients experienced > or = 50% reduction in wet nights after 6 months' treatment than earlier in the study, suggesting the value of persistent treatment.

CONCLUSION

This study shows that long-term desmopressin treatment in the clinical setting is effective and well-tolerated in PNE patients of 5 years and upwards. Early improvements in bedwetting of any appreciable magnitude may be rewarding, may facilitate compliance and enable good long-term response.

Is second-line enuretic alarm therapy after unsuccessful pharmacotherapy superior to first-line therapy in the treatment of monosymptomatic nocturnal enuresis?

INTRODUCTION

We aimed at comparing the success rates of primary enuretic alarm therapy with those of secondary alarm therapy after failed pharmacotherapy in the treatment of monosymptomatic nocturnal enuresis (MNE).

PATIENTS AND METHODS

We randomly applied enuretic alarm therapy in 35 MNE patients (group 1) and desmopressin therapy in 49 MNE patients (group 2). The success and rebound rates after 3 and 6 months were determined. We also applied enuretic alarm therapy as a secondary treatment in 19 group 2 patients with complete rebound after 6 months (group 3). The success rates of patients who have received primary and secondary enuretic alarm therapy were compared.

RESULTS

The success rates for groups 1 and 2 were 82.65 and 81.63%, respectively (p = 0.885), at 3 months and 54.28 and 26.53%, respectively (p = 0.007), at 6 months. The success rates in group 3 were 84.21 and 52.63%, respectively, at 3 and 6 months. When these success rates were compared between groups 1 and 3, no statistically significant difference was found (p = 1.000).

CONCLUSION

Prior pharmacotherapy did not increase success rates of alarm therapy in our MNE patients.

Relief of Nocturnal Enuresis by Desmopressin Is Kidney and Vasopressin Type 2 Receptor Independent

Primary nocturnal enuresis (PNE) is a common problem in childhood and adolescence. Although various treatments are highly effective, a common underlying hypothesis on the pathogenesis is lacking. The success of desmopressin, a synthetic analogue of the antidiuretic hormone vasopressin, has been attributed to increased renal water reabsorption that is mediated by activation of the renal vasopressin V2 receptor (V2R). However, this effect does not explain other symptoms of PNE, such as the failure to arouse upon bladder distension. This study identified a family in which one child displayed PNE and coexisting nephrogenic diabetes insipidus, as a result of a novel nonsense mutation in the V2R gene (C358X). Cell-biologic investigations revealed that V2R-C358X is retained in the endoplasmic reticulum and is unstable, which explains his nephrogenic diabetes insipidus. Consistently, extrarenal V2R-mediated responses were absent in the patient who was treated with desmopressin. Administration of desmopressin, however, changed his PNE into nocturia, because he now still voided unchanged high urinary volumes at night but woke up and went to the bathroom. Withdrawal of desmopressin was accompanied by bedwetting, whereas reintroduction again relieved the symptoms. Therefore, these data indicate that neither a functioning renal concentration system nor a functional V2R is needed for the therapeutic benefit of desmopressin in PNE. Rather, it suggests that another vasopressin receptor and other organ(s) is the target for desmopressin to relieve PNE.

Comparing alarms, desmopressin, and combined treatment in Chinese enuretic children

The objective of this multicenter randomized controlled trial was to compare the efficacy of enuresis alarms, oral desmopressin, and combined treatment in Chinese children with monosymptomatic primary nocturnal enuresis. We assigned 105 children aged 7-15 years to receive alarms (group 1, 35 patients), oral desmopressin 400 mug (group 2, 38 patients), or combined therapy (group 3, 32 patients) for 12 weeks; patients were then followed for 12 weeks after treatment. The wetting frequency decreased during treatment by 46%, 52%, and 73% in groups 1, 2, and 3, respectively. In groups 2 and 3, but not in group 1, there was rebound post treatment, but significant improvements persisted at 12 weeks. The complete and partial response rates were 22.9% and 20%, respectively in group 1, 42% and 10.5% in group 2, and 62.5% and 15.6% in group 3. By Kaplan-Meier analysis, group 1 had a significantly poorer response than groups 2 and 3. Of the responders, 20%, 60%, and 40% in groups 1, 2, and 3, respectively, relapsed after stopping treatment. In conclusion, enuresis alarms and/or oral desmopressin were less efficacious in Chinese than in Western societies. Desmopressin produced an immediate effect but relapses were common. Alarms took several weeks to produce a benefit, which was persistent on follow-up.

Childhood nocturnal enuresis: Developing a conceptual framework

Nocturnal enuresis has been described as the most prevalent and chronic of all childhood problems. The experience, particularly for the older child, can be extremely distressing and limiting. It is now thought that psychological distress (emotional, behavioural, and self-esteem) arises as a consequence of bedwetting, and reaches clinical importance in only a minority who are vulnerable. Many aetiological theories have been proposed with the cause of nocturnal enuresis now regarded as heterogeneous. Based on empirical findings, a new model, termed 'the three systems,' has facilitated a greater clinical understanding of the problem and identification of the appropriate intervention. The model proposes bedwetting results from excessive nocturnal urine production and/or nocturnal bladder overactivity coupled with an inability to arouse to bladder sensations. Effective treatment arises from identification of the child's particular need and application of the appropriate psychological and pharmacological approach. Treatment methods are reviewed in terms of the new model, the mode of action, effectiveness, and application in combination.