To Determine if Diphenhydramine Works for Nasal Congestion at Two Different Doses
Public ClinicalTrials.gov record NCT00648973. Field values are reproduced from the official study page; the official ClinicalTrials.gov record remains the source of truth for eligibility, enrollment, and contact information.
Data is sourced from official ClinicalTrials.gov public API records. Always review the official ClinicalTrials.gov record for the latest information.
Official title
Evaluation of Nasal Congestion Clinical Efficacy for Diphenhydramine 25 mg and Diphenhydramine 50 mg in Seasonal Allergic Rhinitis: a Randomized, Double-blind, Placebo and Pseudoephedrine Controlled Study
Brief summary
Reproduced verbatim from the official ClinicalTrials.gov record. Not medical advice.
The study was to determine if the drug worked to relieve nasal congestion experienced by people with seasonal allergies.
Study identification
- NCT ID
- NCT00648973
- Recruitment status
- Completed
- Study type
- Interventional
- Phase
- Phase 4
- Enrollment
- 1,021 participants
Conditions and interventions
Conditions
Interventions
- Diphenhydramine 50 mg Drug
- Diphenhydramine 25 mg Drug
- Pseudoephedrine 120 mg Drug
Drug
Eligibility (public fields only)
- Age range
- 12 Years to 65 Years
- Sex
- All
- Healthy volunteers
- Healthy volunteers not accepted
This page does not interpret eligibility. Detailed inclusion and exclusion criteria are on the official ClinicalTrials.gov record.
Study timeline
- Start date
- Nov 2006 (Type not available)
- Primary completion
- May 2007 (Actual)
- Completion
- May 2007 (Actual)
- Last update posted
- Aug 22, 2011
2006 – 2007
United States locations
- U.S. sites
- 12
- U.S. states
- 1
- U.S. cities
- 7
| Facility | City | State | ZIP | Site status |
|---|---|---|---|---|
| Benchmark Research - Austin | Austin | Texas | 78705 | — |
| Allergy and Asthma Associates | Austin | Texas | 78731 | — |
| Lovelace Scientific Resources | Austin | Texas | 78759 | — |
| Allergy/Immunology Research Center of North Texas | Dallas | Texas | 75230 | — |
| Kerrville Research Associates | Kerrville | Texas | 78028 | — |
| Central Texas Health Research | New Braunfels | Texas | 78130 | — |
| Benchmark Research - San Angelo | San Angelo | Texas | 76904 | — |
| Sun Research Institute | San Antonio | Texas | 78205 | — |
| Biogenics Research Institute | San Antonio | Texas | 78229 | — |
| Diagnostics Research Group | San Antonio | Texas | 78229 | — |
| Sylvana Research Associates | San Antonio | Texas | 78229 | — |
| Allergy Asthma Research Institute | Waco | Texas | 76712 | — |
Site contact phone numbers, emails, and investigator names are intentionally not displayed here. Open the official ClinicalTrials.gov record for site contact information.
About this trial record page
- What this page shows
- Public field values for ClinicalTrials.gov record NCT00648973, including study identification, conditions, interventions, eligibility (age, sex, healthy volunteer), timeline, and U.S. site list.
- What this page does not do
- No medical advice, eligibility judgments, treatment recommendations, study quality scoring, or AI-generated medical summaries. No site contact phone numbers, emails, or investigator names.
- Where the data comes from
- Sourced from the official ClinicalTrials.gov public API. The official record is the source of truth.
- Last refresh
- Last update posted Aug 22, 2011 · Synced Nov 3, 2026
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Open the official record
The complete public registry record, listed eligibility criteria, and available contact information for NCT00648973 live on ClinicalTrials.gov.