Treatment of NB and OAB is behavioral therapy, such as bladder-training strategies, pelvic-floor physiotherapy, fluid management, and medications. The most common side-effects of antichomuscarinic drugs are dry mouth (xerostomia). Xerostomia is a major factor affecting patient compliance for taking antimuscarinic drugs. The complications of xerostomia can lead to speech problems, taste disorders, chewing difficulties, swallowing difficulties, and ill-fitting dentures. Consequently, these complications lead to a poor QoL and increase the risk of developing infectious oral diseases such as caries, oral mucositis, periodontitis, and oral candidiasis. To improve patient compliance and avoid the side-effect of xerostomia, an oral sialogogue, “Oryza tablet” (OT), was developed. Here, we investigated the efficacy of OT in improving xerostomia in patients with NB or OAB who received antimuscarinic drugs.

This was a randomized clinical trial. Twenty-eight patients (median age = 64 years) with xerostomia were divided into two groups: OT (intervention group) and placebo (control) group. Both groups comprised 14 patients each. We assessed severity using a questionnaire for the subjective evaluation of xerostomia. Objective evaluation was undertaken for the stimulated salivary flow rate (SSFR). Xerostomia evaluation took place before treatment (baseline) as well as 2 weeks and 4 weeks after treatment.

The xerostomia score decreased significantly (p < 0.05) compared with that of the placebo group after treatment (score at 2 weeks was 4.4 in the placebo group compared with 2.75 in the OT group; score at 4 weeks was 4.13 in the placebo compared with 2.19 in the OT group). The SSFR increased significantly at 2 weeks and 4 weeks after treatment (1.2 and 1.1 in the placebo group compared with 2 and 1.85 in the OT group, respectively, p < 0.05). No patient stopped taking antimuscarinic drugs during the study. No adverse events were reported.

Continuous daily use of OT for 4 weeks led to an improvement in overall subjective xerostomia symptoms and saliva production (p < 0.05). With respect to xerostomia symptoms after treatment, longer use of antimuscarinic medications led to improvements in lip dryness and speaking difficulty (comparison between 2 weeks and 4 weeks after treatment). The SSFR of all patients at baseline was 1.13 mL/min (SSFR was considered to be low at 0.7–1.0 mL/min), which was considered to be within the normal range. However, an improvement in saliva production was observed which correlated with the clinical outcome of xerostomia symptoms after treatment. All patients were instructed to take medication four times per day. The average number of tablets remaining after a full course of treatment was 8.9. Therefore, a further study on the optimal daily dose (e.g., three times per day or as-needed use) may increase patient with treatment.

Continuous daily use of Oryza tablet for 4 weeks reduced xerostomia symptoms and increased saliva production in patients suffering from NB or OAB who received antimuscarinic medications.

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Continence 7S1 (2023) 100754
DOI: 10.1016/j.cont.2023.100754