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NCT Number: NCT05586477

Diphenhydramine and Sweating

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.

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Key information

Conditions

Diphenhydramine Causing Adverse Effects in Therapeutic Use Allergic Rhinitis Body Temperature Changes Heat Stress Disorders Hypersensitivity Hypersensitivity, Immediate Hyperthermia Immune System Diseases Nose Diseases Otorhinolaryngologic Diseases Pathological Conditions, Signs and Symptoms Respiratory Hypersensitivity Respiratory Tract Diseases Rhinitis Rhinitis, Allergic Signs and Symptoms Sweating Wounds and Injuries

Age range

18 year–49 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Lakehead Unviersity

Thunder Bay, Ontario, P7B 5E1, Canada

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Placebo

Drug

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

diphenhydramine

Drug

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

Primary outcomes

  1. Whole body sweat loss

    Time frame: 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 outcomes

  1. Change in rectal temperature

    Time frame: 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

Sponsors and collaborators

Lead sponsor

Lakehead University

Other

Registry information

Official study title

Does Diphenhydramine Alter Thermoregulatory Responses During Exercise?

Acronym: BENEXE2022

Important dates

Study start
2022
Primary completion
2023
Study completion
2023
First posted
Oct 19, 2022
Registry last updated
Sep 13, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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