A non-randomized, open-label, single arm study to evaluate the effect of Yokukansan on the dispositions of donepezil hydrochloride and risperidone (clinical pharmacokinetic analysis)

A non-randomized, open-label, single arm study to evaluate the effect of Yokukansan on the dispositions of donepezil hydrochloride and risperidone (clinical pharmacokinetic analysis) - A study to evaluate the effect of Yokukansan on the dispositions of donepezil hydrochloride and risperidone

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000026273

Enrollment

Registered

2017-04-01

Start date

2017-12-06

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Dementia or Schizophrenia

Interventions

8-week repeated doses of Yokukansan (7.5 g per day)

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: Patients with dementia who have been treated with donepezil hydrochloride for more than 4 weeks, or patients with schizophrenia who have been treated with risperidone for more than 2 weeks

Exclusion criteria

Exclusion criteria: Not available

Design outcomes

Primary

Measure	Time frame
Variabilities in blood concentrations of donepezil hydrochloride, risperidone and their metabolites before and after co-treatment of Yokukansan	—

Secondary

Measure	Time frame
Variabilities in blood concentrations of donepezil hydrochloride, risperidone and their metabolites before and after co-treatment of Yokukansan according to the genotypes of pharmacokinetic related genes	—

Countries

Japan

Contacts

Public ContactJunji Saruwatari

Graduate School of Pharmaceutical Sciences, Kumamoto University Division of Pharmacology and Therapeutics

junsaru@gpo.kumamoto-u.ac.jp+81-96-371-4545

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026