EFFICACY AND SAFETY OF 25 AND 50 μg DESMOPRESSIN ORALLY DISINTEGRATING TABLETS IN NOCTURIA DUE TO NOCTURNAL POLYURIA IN JAPANESE MALE PATIENTS

Abstract

Purpose) To conduct a prospective study on the efficacy and safety of desmopressin for nocturnal polyuria.(Materials and methods) We selected 51 Japanese men, aged !50 years, with complaints of nocturia and a nocturnal polyuria index of !0.33. We administered 25 or 50 μg desmopressin (Minirinmelt Orally Disintegrating Tablet Ⓡ ), once daily at bedtime. We evaluated the nighttime urinary frequency and urine volume, nocturnal polyuria index, time to the first urination after falling asleep, and International Prostate Symptom Score (IPSS) at baseline and at 4, 8, and 12 weeks after administration. In addition, they underwent clinical examinations and blood tests at 1, 4, and 12 weeks to evaluate the safety of the drug.(Results) We observed a decrease in the nighttime urinary frequency and urine volume, and nocturnal polyuria index, increased prolonged time to the first urination after falling asleep, and improved IPSS at and after 4 weeks, compared to baseline data. Furthermore, the drug remained effective even at 12 weeks for all parameters. We observed adverse events in 31.3% of the patients. The incidence of hyponatraemia was particularly high in 15.7% of the patients.Those with a lower serum sodium level and lesser body weight at baseline were more likely to develop hyponatraemia.(Conclusion) Desmopressin was identified as a potential drug for the treatment of nocturnal polyuria. However, hyponatraemia, an important adverse event, resulted in treatment discontinuation in several patients. A sodium level lower than the normal level and low body weight at baseline were the risk factors for hyponatraemia.

Determining the optimal initial dose for Japanese patients with nocturnal polyuria using an initial dose of desmopressin 50 μg

“…7 Additionally, Hayashi et al found that HUS was significantly extended in the 50 μg group, but not significantly extended in the 25 μg group. 9 The report by Kyoda et al found no significant difference in the onset of hyponatremia between the initial doses of 50 or 25 μg. 7 Based on the results of these studies, the initial dose of desmopressin was set as 50 μg in this study.…”

“…A study by Kyoda et al on clinical practice in Japanese patients reported that the frequency of night‐time urination reduced 1.3 times compared with the baseline in the desmopressin 25 μg group, and 1.8 times in the 50 μg group with 1 to 3 months of treatment, demonstrating a dose‐dependent therapeutic effect 7 . Additionally, Hayashi et al found that HUS was significantly extended in the 50 μg group, but not significantly extended in the 25 μg group 9 . The report by Kyoda et al found no significant difference in the onset of hyponatremia between the initial doses of 50 or 25 μg 7 .…”

“…Desmopressin was approved in Japan in 2019 for the treatment of nocturia associated with nocturnal polyuria in men; however, evidence is currently being accumulated. [7][8][9] The initial dose was 25 μg for approximately 45% of cases in the clinical data on 118 cases recently reported by Kyoda et al 7 The initial dose in clinical practice is often decided at the discretion of the individual doctor, and this is the first report on the optimal uniform initial dose of desmopressin for Japanese patients.…”

“…Regarding concerns about the safety of 50 μg as the initial dose, a report by Hayashi et al found that adverse events occurred in 31.3% of cases, and hyponatremia occurred in 15.7% of cases (25 μg group: 10.5%, 50 μg group: 18.8%) 9 . In this study, the incidence of hyponatremia was slightly higher than existing reports (18.7%), but 5.0% of cases still had hyponatremia after the dose was reduced to 25 μg, which is comparable to existing reports 8,13,14 .…”

Investigation of Effect Predictors of Desmopressin in Nocturia Patients With Nocturnal Polyuria

“…Desmopressin was approved in Japan in 2019 for the treatment of nocturia associated with nocturnal polyuria in men, and evidence regarding its safety and efficacy is currently being accumulated. However, reports regarding effect predictors of desmopressin are scarce (8,12). Nocturia is known to affect sleep; in particular, a nocturnal voiding frequency >2 reduces sleep quality and total sleep time, and decreases sleep quality and QOL (13).…”