Effect of an H1 Receptor Antagonist on Exercise Performance in Hypoxia

Study Overview
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Brief Summary
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This study seeks to determine whether a simple, single intervention of Cetirizine / Zyrtec® use can improve exercise performance of active individuals when acutely exposed to altitude. For this project, healthy subjects will perform steady state and progressive work rate exercise, endurance performance time trials, and repeated sprint performance time trials in the laboratory at a simulated altitude of 3000m (9900ft) after dosing with 10 mg of Cetirizine or a placebo in a repeated measures design.

Detailed Description
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This study seeks to determine whether a simple, single intervention of Cetirizine / Zyrtec® use can improve exercise performance of active individuals when acutely exposed to altitude. For this project, healthy subjects will perform steady state and progressive work rate exercise, endurance performance time trials, and repeated sprint performance time trials in the laboratory at a simulated altitude of 3000m (9900ft) after dosing with 10 mg of Cetirizine or a placebo in a repeated measures design. Non-invasive techniques (pulse oximetry, near-infrared spectroscopy [NIRS]) will be utilized to measure changes in arterial oxyhemoglobin saturation and skeletal muscle oxygenation at the level of the microvasculature during exercise. It is expected that after Cetirizine, blood and muscle microvascular oxygenation during heavy exercise will improve compared to placebo, ultimately improving exercise performance at altitude. Subjects will be asked to report to the laboratory on a three occasions, separated by a minimum of 48 hours and a maximum of 14 days. For each subject, all testing sessions will be performed at the same time of day. Prior to each testing session, subjects will be asked to abstain from caffeine consumption for 12 hours. Subjects will also be asked to avoid alcohol consumption for 24 hours before testing, be at least 3-hour post prandial and avoid high-intensity exercise during the 24 hours leading to the exercise testing. Finally, subjects will be asked to consume a similar diet the night before, and the morning of, Sessions 2 and 3.

Official Title
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Effect of an H1 Receptor Antagonist on Exercise Performance in Hypoxia

Conditions
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Hypoxia, Altitude

Intervention / Treatment
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* Drug: Cetirizine
* Drug: Placebo oral capsule
* Other: Hypoxia


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Physically active a minimum of 120 minutes a week, as determined by questionnaire 18-35 years of age Classified as low risk, based on the modified PAR-Q questionnaire, BMI, and non-smoking status No history of pulmonary disease and pulmonary function classified as normal, as defined by the following measurements being 80% of predicted values: forced vital capacity (FVC), forced expired volume in one second (FEV1) and FEV1/FVC, according to the American Thoracic Society standards. Exclusion Criteria: Current smoker Women who are pregnant or could possibly be pregnant BMI > 25 kg/m2 A 'yes' answer to any of the 14 questions on the PAR-Q pre-participation questionnaire History of pulmonary disease or <80% of predicted FCV, FEV1 and/or FEV1/FVC. A history of renal or liver disease, due to possible interaction effect with Cetirizine Currently taking any prescription or over the counter medications for the treatment of allergies, or taking any of the below listed drugs known to have a moderate or higher interaction effect with Cetirizine: isocarboxazid tranylcypromine bosutinib clobazam crizotinib daclatasvir eliglustat hyaluronidase lomitapide lurasidone ombitasvir/paritaprevir/ritonavir phenelzine ponatinib ritonavir vemurafenib

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Cetirizine/Hypoxia<br>Subjects orally ingested 10 mg of Cetirizine 60 min before exercising in a normobaric hypoxic environment (14.3% oxygen simulating an altitude of 3,000m/9,000ft). | Drug: Cetirizine<br>* Cetirizine tablet 10 mg<br>* Other names: Zyrtec;Other: Hypoxia<br>* Exposure to a 14.3% oxygen environment simulating an altitude of 3,000m/9,000ft<br>* Other names: altitude, low-oxygen environment;|
| Placebo Comparator: Placebo/Normoxia<br>Subjects orally ingested a 10 mg gelatin Placebo 60 min before exercising in a normoxic (room-air) environment (20.9% oxygen). | Drug: Placebo oral capsule<br>* Gelatin placebo<br>|
| Placebo Comparator: Placebo/Hypoxia<br>Subjects orally ingested a 10 mg Placebo 60 min before exercising in a normobaric hypoxic environment (14.3% oxygen simulating an altitude of 3,000m/9,000ft). | Drug: Placebo oral capsule<br>* Gelatin placebo<br>Other: Hypoxia<br>* Exposure to a 14.3% oxygen environment simulating an altitude of 3,000m/9,000ft<br>* Other names: altitude, low-oxygen environment;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Performance Time | Time to complete 8km cycling time trial | Performed 60min after pill ingestion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Plasma Histamine Concentrations at Baseline and Post-Exercise | Plasma histamine concentrations (ng/mL) were determined baseline and post-exercise for each experimental condition. Baseline measures were taken immediately prior to exercise and the post-exercise measures were taken 5-10 minutes after the cessation of exercise. | baseline and immediately post-exercise, same day as pill ingestion |