Brief Summary

The purpose of this study is to evaluate the antitussive (cough-suppressing) effects of two liquid medications: a combination of diphenhydramine and phenylephrine in a naturally cocoa flavoring, and, dextromethorphan syrup, compared with placebo.

Trial Health

On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment

participants targeted

Target at below P25 for phase_4

Timeline

Completed

Started Jan 2014

Shorter than P25 for phase_4

Geographic Reach

1 country

1 active site

Status

completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

5 months study duration

Study Start

First participant enrolled

January 1, 2014

Completed

1 month until next milestone

First Submitted

Initial submission to the registry

January 31, 2014

Completed

14 days until next milestone

First Posted

Study publicly available on registry

February 14, 2014

Completed

4 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

June 1, 2014

Completed

Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

June 1, 2014

Completed

11 months until next milestone

Results Posted

Study results publicly available

April 28, 2015

Completed

Last Updated

February 28, 2018

Status Verified

February 1, 2018

Enrollment Period

5 months

First QC Date

January 31, 2014

Results QC Date

September 16, 2014

Last Update Submit

February 26, 2018

Conditions

Cough Reflex Sensitivity

Keywords

coughcough reflexcapsaicindiphenhydraminephenylephrinedextromethorphanplacebo

Outcome Measures

Primary Outcomes (1)

Change in Cough Reflex Sensitivity to Capsaicin
increase in C5 (decrease in cough reflex sensitivity). Capsaicin cough challenge involves subjects breathing in incremental doubling concentrations of aerosolized capsaicin, 1 minute apart, until the concentration of capsaicin (micromolar) inducing 5 or more coughs (C5) is reached.
2 hours after study drug administration

Study Arms (6)

A, B, then C

EXPERIMENTAL

Subjects received the following: Period 1: single oral dose of diphenhydramine 25 mg and phenylephrine 10 mg, in naturally-flavored cocoa syrup (treatment A). Period 2: dextromethorphan syrup 30 mg (treatment B); Period 3: placebo liquid, dextrose in water, 20 mL (treatment C). Intervention: capsaicin cough challenge testing 2 hours after study drug ingestion.Each dosing period separated by 1-2 day washout period.

Drug: diphenhydramine/phenylephrine/cocoa; dextromethorophan; placeboDrug: diphenhydramine/phenylephrine/cocoa; placebo; dextromethorphanDrug: dextromethorphan; diphenhydramine/phenylephrine/cocoa; placeboDrug: dextromethorophan; placebo; diphenhydramine/phenylephrine/cocoaDrug: placebo; diphenhydramine/phenylephrine/cocoa; dextromethorphanDrug: placebo; dextromethorphan; diphenhydramine/phenylephrine/cocoa

A, C, then B

EXPERIMENTAL

Subjects received the following: Period 1: single oral doce of diphenhydramine 25 mg and phenylephrine 10 mg, in naturally-flavored cocoa syrup (treatment A); Period 2: placebo liquid, dextrose in watwer, 20 mL (treatment C); Period 3: dextromethorphan syrup 30 mg (treatment B). Intervention: capsaicin cough challenge testing 2 hours after study drug ingestion.Each dosing period separated by 1-2 day washout period.

B, A, then C

EXPERIMENTAL

Subjects received the following: Period 1: dextromethorphan syrup 30 mg (treatment B); Period 2: single dose of oral diphenhydramine 25 mg and phenylephrine 10 mg, in a naturally-flavored cocoa syrup (treatment A); Period 3: placebo liquid, dextrose in water, 20 mL (treatment C). Intervention: capsaicin cough challenge testing 2 hours after study drug ingestion. Each dosing period separated by 1-2 day washout period.

B, C, then A

EXPERIMENTAL

Subjects received the following: Period 1: dextromethorphan 30 mg syrup (treatment B); Period 2: placebo liquid, dextrose in water, 20 mL (treatment C); Period 3: single dose of oral diphenhydramine 25 mg and phenylephrine 10 mg in a naturally-flavored cocoa syrup (treatment A). Intervention: capsaicin cough challenge testing 2 hours after study drug ingestion. Each dosing period separated by 1-2 day washout period.

C, A, then B

EXPERIMENTAL

Subjects received the following: Period 1: placebo liquid, dextrose in water, 20 mL (treatment C); Period 2: a single oral dose of diphenhydramine 25 mg and phenylephrine 10 mg in a naturally-flavored cocoa syrup (treatment A); Period 3: dextromethorphan 30 mg syrup (treatment B). Intervention: capsaicin cough challenge testing 2 hours after study drug ingestion. Each dosing period separated by 1-2 day washout period.

C, B, then A

EXPERIMENTAL

Subjects received the following: Period 1: placebo liquid, dextrose in water, 20 mL (treatment C); Period 2: dextromethorphan 30 mg syrup (treatment B); Period 3: a single oral dose of diphenhydramine 25 mg and phenylephrine 10 mg in a naturally-flavored cocoa syrup (treatment A). Intervention: capsaicin cough challenge testing 2 hours after study drug ingestion. Each dosing period separated by 1-2 day washout period.