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Anti-histamines and Methacholine Challenges.

This study is not yet open for participant recruitment. (see Contacts and Locations)
Verified November 2013 by University of Saskatchewan
Information provided by (Responsible Party):
Don Cockcroft, University of Saskatchewan Identifier:
First received: October 31, 2013
Last updated: November 8, 2013
Last verified: November 2013

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.

Condition Intervention Phase
Drug: Diphenhydramine
Drug: cetirizine
Drug: desloratadine
Drug: placebo
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Diagnostic
Official Title: The Effect of Antihistamines on Methacholine Challenge Testing in Asthma Patients

Resource links provided by NLM:

Further study details as provided by University of Saskatchewan:

Primary Outcome Measures:
  • change in methacholine pc20 [ Time Frame: change from baseline (pre dose) at 2 hours (post dose) ] [ Designated as safety issue: No ]

Estimated Enrollment: 15
Study Start Date: November 2013
Estimated Study Completion Date: March 2014
Estimated Primary Completion Date: March 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
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:

  • pregnant or breastfeeding females
  • unable to withhold antihistamines, anticholinergics, long acting bronchodilators and combination therapies
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01985789

Contact: Beth Davis, PhD 306-966-8291

Canada, Saskatchewan
University of Saskatchewan Not yet recruiting
Saskatoon, Saskatchewan, Canada, S7N 0W8
Contact: Beth Davis, PhD    306-966-8291   
Sub-Investigator: Beth E Davis, PhD         
Sponsors and Collaborators
Don Cockcroft
Principal Investigator: Donald W Cockcroft, MD University of Saskatchewan, Department of Medicine, Division of Respirology, Critical Care and Sleep Medicine
  More Information

No publications provided

Responsible Party: Don Cockcroft, Professor, University of Saskatchewan Identifier: NCT01985789     History of Changes
Other Study ID Numbers: PHPY2013/14
Study First Received: October 31, 2013
Last Updated: November 8, 2013
Health Authority: Canada: Health Canada

Keywords provided by University of Saskatchewan:
airway hyperresponsiveness

Additional relevant MeSH terms:
Anesthetics, Local
Anti-Allergic Agents
Autonomic Agents
Central Nervous System Agents
Central Nervous System Depressants
Cholinergic Agents
Cholinergic Antagonists
Gastrointestinal Agents
Histamine Agents
Histamine Antagonists
Histamine H1 Antagonists
Histamine H1 Antagonists, Non-Sedating
Hypnotics and Sedatives
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Peripheral Nervous System Agents
Pharmacologic Actions
Physiological Effects of Drugs
Sensory System Agents
Therapeutic Uses processed this record on March 26, 2015