BENEXE2022: Diphenhydramine and Sweating

Sponsor

Lakehead University (Other)

Overall Status

Recruiting

CT.gov ID

NCT05586477

Collaborator

(none)

Enrollment

Location

Arms

Anticipated Duration (Months)

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

In 2012, it was estimated that nearly 1 in 4 Canadians suffer from allergic rhinitis. To add, 78% of individuals working in predisposing environments are predicted to develop occupational rhinitis. Currently, the most popular treatment for rhinitis is antihistamine medication such as diphenhydramine, a first-generation antihistamine sold commercially as Benadryl®. Due it its anticholinergic effects, diphenhydramine has been suggested to impair the whole body sweating response during heat stress, potentially leaving consumers at an increased risk of heat-related illness. This randomized control trial approved by Health Canada will investigate whether ingesting extra strength diphenhydramine (50mg) will alter whole-body sweat losses during 60 minutes of exercise.

Condition or Disease	Intervention/Treatment	Phase
Diphenhydramine Causing Adverse Effects in Therapeutic Use Hyperthermia Allergic Rhinitis Sweating	Drug: Placebo Drug: Diphenhydramine	Phase 4

Study Design

Study Type:

Interventional

Anticipated Enrollment :

20 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Masking:

Single (Participant)

Masking Description:

Single-blind

Primary Purpose:

Treatment

Official Title:

Does Diphenhydramine Alter Thermoregulatory Responses During Exercise?

Anticipated Study Start Date :

Nov 1, 2022

Anticipated Primary Completion Date :

Sep 1, 2023

Anticipated Study Completion Date :

Sep 1, 2023

Arms and Interventions

Arm	Intervention/Treatment
Other: Intervention Order (Placebo - Diphenhydramine) On separate days, participants will march on a treadmill for 60 minutes at a fixed rate of oxygen consumption (~1.75 liters of oxygen consumption per minute) in ~25°C and 50% relative humidity	Drug: Placebo A placebo pill (i.e., sugar) will be consumed 2 h before intervention. Drug: Diphenhydramine Extra strength Benadryl (DIN 02470144) will be consumed 2 h before intervention
Other: Intervention Order (Diphenhydramine -Placebo) On separate days, participants will march on a treadmill for 60 minutes at a fixed rate of oxygen consumption (~1.75 liters of oxygen consumption per minute) in ~25°C and 50% relative humidity	Drug: Placebo A placebo pill (i.e., sugar) will be consumed 2 h before intervention. Drug: Diphenhydramine Extra strength Benadryl (DIN 02470144) will be consumed 2 h before intervention

Arm

Intervention/Treatment

Other: Intervention Order (Placebo - Diphenhydramine)

On separate days, participants will march on a treadmill for 60 minutes at a fixed rate of oxygen consumption (~1.75 liters of oxygen consumption per minute) in ~25°C and 50% relative humidity

Drug: Placebo

A placebo pill (i.e., sugar) will be consumed 2 h before intervention.

Drug: Diphenhydramine

Extra strength Benadryl (DIN 02470144) will be consumed 2 h before intervention

Other: Intervention Order (Diphenhydramine -Placebo)

On separate days, participants will march on a treadmill for 60 minutes at a fixed rate of oxygen consumption (~1.75 liters of oxygen consumption per minute) in ~25°C and 50% relative humidity

Drug: Placebo

A placebo pill (i.e., sugar) will be consumed 2 h before intervention.

Drug: Diphenhydramine

Extra strength Benadryl (DIN 02470144) will be consumed 2 h before intervention

Outcome Measures

Primary Outcome Measures

Whole body sweat loss [Measured during both placebo and diphenhydramine intervention trials trials, separated by no more than 28 days]
Change in body mass from pre- to post-exercise corrected for respiratory and metabolic water losses using a digital platform scale accurate to +/- 2 grams.

Secondary Outcome Measures

Change in rectal temperature [Measured during both placebo and diphenhydramine intervention trials trials, separated by no more than 28 days]
Change in rectal temperature from pre- to post- exercise using a pediatric grade thermistor

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 49 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Able to safely perform ~60 minutes of moderate intensity exercise
No known hypersensitivity to diphenhydramine
Not on any prescribed medication
Body-mass index (BMI) less than 30

Exclusion Criteria:

Outside 18 - 49 years of age
Diagnosed with any cardiovascular, respiratory, neurological or metabolic disease
History of any cardiovascular, respiratory, neurological or metabolic disease
Unable to exercise for 60 minutes at moderate intensity, or have a musculoskeletal injury
BMI > or = 30