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Anti-histamines and Methacholine Challenges.

This study has been completed.
Information provided by (Responsible Party):
Don Cockcroft, University of Saskatchewan Identifier:
First received: October 31, 2013
Last updated: April 7, 2015
Last verified: April 2015
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 ]

Enrollment: 12
Study Start Date: November 2013
Study Completion Date: May 2014
Primary Completion Date: May 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   (Adult, Senior)
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

Canada, Saskatchewan
University of Saskatchewan
Saskatoon, Saskatchewan, Canada, S7N 0W8
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

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: April 7, 2015
Health Authority: Canada: Health Canada

Keywords provided by University of Saskatchewan:
airway hyperresponsiveness

Additional relevant MeSH terms:
Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Lung Diseases
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases
Methacholine Chloride
Anti-Allergic Agents
Histamine H1 Antagonists, Non-Sedating
Histamine H1 Antagonists
Histamine Antagonists
Histamine Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs
Autonomic Agents
Peripheral Nervous System Agents
Bronchoconstrictor Agents
Respiratory System Agents
Muscarinic Agonists
Cholinergic Agonists processed this record on October 27, 2016