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Clinical Trials/NCT01985789
NCT01985789CompletedPhase 4

The Effect of Antihistamines on Methacholine Challenge Testing in Asthma Patients

Don Cockcroft1 site in 1 country12 target enrollmentStarted: November 2013Last updated:
Conditions
Interventions
Drugs

Trial Snapshot

Phase
Phase 4
Status
Completed
Sponsor
Enrollment
12
Locations
1
Primary Endpoint
change in methacholine pc20

Study Overview

Brief 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.

Study Design

Study Type
Interventional
Allocation
Randomized
Intervention Model
Crossover
Primary Purpose
Diagnostic
Masking
Triple (Participant, Investigator, Outcomes Assessor)

Eligibility Criteria

Ages
18 Years to — (Adult, Older Adult)
Sex
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

Exclusion Criteria

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

Arms & Interventions

diphenhydramine

Active Comparator

50mg dose given as two 25mg capsules

Intervention: Diphenhydramine (Drug)

cetirizine

Active Comparator

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

Intervention: cetirizine (Drug)

desloratadine

Active Comparator

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

Intervention: desloratadine (Drug)

placebo

Placebo Comparator

given as 2 placebo capsules

Intervention: placebo (Drug)

Outcomes

Primary Outcomes

change in methacholine pc20

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

Secondary Outcomes

No secondary outcomes reported

Investigators

Sponsor
Don Cockcroft
Sponsor Class
Other
Responsible Party
Sponsor Investigator
Principal Investigator

Don Cockcroft

Professor

University of Saskatchewan

Study Sites (1)

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