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CompletedNCT01985789Updated Apr 8, 2015

Anti-histamines and Methacholine Challenges.

A Phase 4 interventional study of Diphenhydramine and cetirizine in Asthma, sponsored by Don Cockcroft. Completed at 1 site in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2015-04-08.

Sponsored by Don Cockcroft · Phase 4, Interventional, and Diagnostic

Phase
Phase 4
Study type
Interventional
Enrollment
12
Allocation
Randomized
Ages
18 Years and older
Sex
All
01

Study summary

The asthmatic airway is identified and studied using inhaled agents such as histamine and methacholine. The use of antihistamines prior to the test will inhibit the test result if histamine is used to cause airway constriction. If using methacholine, this may also be true depending on whether old (e.g. benadryl) or new (e.g. desloratadine) antihistamines are used. This study will look at the effect of old and new antihistamines on inhaled methacholine challenge response in individuals with mild asthma.

02

Conditions studied

  • Asthma

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Keywords

  • airway hyperresponsiveness
03

In context

Asthma

3,921 studies on the registry are indexed under Asthma; 507 are open to participants now.

This study's enrollment of 12 is below the median of 83 across 2,752 interventional studies indexed under Asthma.

Browse Asthma studies →

Lead sponsor

This is the only study on the registry with Don Cockcroft as lead sponsor.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Baseline forced expiratory volume in 1s (FEV1) of 70% or more of predicted
  • Methacholine provocative concentration causing a 20% fall in FEV1 16mg/ml or less
  • No respiratory infection or change in allergen exposure for 4 weeks prior to screening and throughout the study
  • No significant medical co-morbidities
  • allergy

Exclusion criteria

Exclusion Criteria:

  • pregnant or breastfeeding females
  • unable to withhold antihistamines, anticholinergics, long acting bronchodilators and combination therapies
05

Study design

Phase
Phase 4
Primary purpose
Diagnostic
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Triple (Participant, Investigator, Outcomes assessor)
Enrollment
12 participants (actual)

Study arms

  • Active comparator
    diphenhydramine

    50mg dose given as two 25mg capsules

    Drug: Diphenhydramine

  • Active comparator
    cetirizine

    10mg dose given as 1 10mg capsule and 1 placebo capsule

    Drug: cetirizine

  • Active comparator
    desloratadine

    5mg dose given as 1 5mg capsule and 1 placebo capsule

    Drug: desloratadine

  • Placebo comparator
    placebo

    given as 2 placebo capsules

    Drug: placebo

Interventions

  • DrugDiphenhydramine
  • Drugcetirizine
  • Drugdesloratadine
  • Drugplacebo
06

What researchers measure

Primary outcomes

  1. change in methacholine pc20

    Time frame: change from baseline (pre dose) at 2 hours (post dose)

07

Study locations

1 site
  • University of Saskatchewan
    Saskatoon, Saskatchewan S7N 0W8, Canada
08

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Apr 8, 2015, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT01985789
Lead sponsor
Don Cockcroft
Responsible party
Don Cockcroft (Professor, University of Saskatchewan) — Sponsor-investigator
First posted
Nov 15, 2013
Start date
Nov 2013
Primary completion
May 2014
Completion
May 2014
Last update
Apr 8, 2015

Study contacts

Donald W Cockcroft, MD
principal investigator · University of Saskatchewan, Department of Medicine, Division of Respirology, Critical Care and Sleep Medicine

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Apr 2015. You cannot join it, but the record below documents what was studied.

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