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Brain histamine H1 receptor occupancy of sedating OTC antihistamines: Time-course of receptor occupancy measured by PET in normal volunteers

Brain histamine H1 receptor occupancy of sedating OTC antihistamines: Time-course of receptor occupancy measured by PET in normal volunteers - Histamine H1 receptor occupancy of OTC antihistamines

Status
Active, not recruiting
Phases
Phase 4
Study type
Interventional
Source
JPRN
Registry ID
JPRN-UMIN000011372
Enrollment
8
Registered
2013-08-05
Start date
2013-08-01
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

Normal volunteers

Interventions

Ketotifen 1.38 mg Diphenhydramine 50 mg

Sponsors

Department of Pharmacology, Tohoku University Graduate School of Medicine
Lead Sponsor

Eligibility

Sex/Gender
Male

Inclusion criteria

Inclusion criteria: 1. Normal volunteers with his own free will. There is no subordinate relation. 2. Male healthy volunteers aged 20-30 years old, who understand the purpose of this study. 3. Subjects who can take enough sleep and rest at the previous night of PET scans 4. Subjects who can read documents attached with e-mail. 5. Subjects who can communicate with mobile phones. 6. Subjects who can take 3 PET-sacns examination and 1 MRI scan.

Exclusion criteria

Exclusion criteria: 1. Subjects who take no medication including antihistamines at present. 2. Subjects who do not take any PET scans within the recent 2 years. 3. No serious allergy 4. No convulsion at past 5. No frequent medical addmission 6. No glaucoma and prostatic hypertrophy 7. Subjects who can not take any anticholinergic and antihistaminergic drugs from medical points of view. 8. No brain MRI abnormality 9. Inadequate subjects from the point of medical view of the investigators.

Design outcomes

Primary

MeasureTime frame
Brain histamine H1 receptor occupancy 3 and 23 hours after oral administration of ketotifen 1.38 mg and diphenhydramine 50 mg.

Secondary

MeasureTime frame
Subjective sleepiness scale 3 and 23 hours after oral administration of ketotifen 1.38 mg and diphenhydramine 50 mg.

Countries

Japan

Contacts

Public ContactYanai Kazuhiko

Tohoku University Graduate School of Medicine Pharmacology

yanai@med.tohoku.ac.jp022-717-8055

Outcome results

None listed

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