Open-label, single-center, randomized and parallel-group study to compare the efficacy of olopatadine hydrochloride and dextromethorphan hydrobromide in prolonged and chronic cough

Open-label, single-center, randomized and parallel-group study to compare the efficacy of olopatadine hydrochloride and dextromethorphan hydrobromide in prolonged and chronic cough - Study to compare the efficacy of olopatadine hydrochloride and dextromethorphan hydrobromide in prolonged and chronic cough

Status

Active, not recruiting

Phases

Phase 4

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000001009

Enrollment

Registered

2008-02-01

Start date

2008-02-01

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

Prolonged and chronic cough

Interventions

olopatadine hydrochloride 5mg b.i.d, for 2 weeks dextromethorphan hydrobromide 15mg t.i.d, for 2 weeks

Eligibility

Sex/Gender

All

Inclusion criteria

Inclusion criteria: 1. Cough persisting for longer than 3 weeks. 2. No radiological evidence of chest disease. 3. Who gave written informed consent.

Exclusion criteria

Exclusion criteria: 1. Patients with a history of hypersensitivity to olopatadine hydrochloride or dextromethorphan hydrobromide 2. Patients receiving monoamine oxidase inhibitor (MAOI) therapy and for 14 days after stopping MAOI therapy 3. Patients with a history of other chest disease 4. Patients taking angiotensin-converting enzyme inhibitors. 5. Patients during pregnancy or lactation 6. Inappropriate patients from the doctor's viewpoint

Design outcomes

Primary

Measure	Time frame
Symptom scores and VAS score(at 0 and 2 weeks) Capsaicin cough sensitivity test(at 0 and 2weeks) Concentrations of substance P in sputum and plasma(at 0 and 2weeks)	—

Secondary

Measure	Time frame
1. Pulmonary function tests(at 0 and 2weeks) 2. Inflammatory biomarkers of induced sputum and serum(at 0 and 2weeks) 3. Exhaled nitric oxide concentration(at 0 and 2weeks) 4. Parameters of impulse oscillometry(at 0 and 2weeks) 5. safety	—

Countries

Japan

Contacts

Public ContactKojiro Otsuka

Kyoto University Graduate School of Medicine Department of Respiratory Medicine

075-751-3830

Outcome results

None listed

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