Diphenhydramine and Sweating (BENEXE2022)

Lakehead University

Status and phase: Completed; Phase 4

Conditions: Allergic Rhinitis; Sweating; Hyperthermia; Diphenhydramine Causing Adverse Effects in Therapeutic Use

Treatments: Drug: Placebo; Drug: Diphenhydramine

Study type: Interventional

Funder types: Other

Identifiers

NCT05586477

2022509

265937 (Other Identifier)

Details and patient eligibility

About

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.

Enrollment: 20 patients

Sex: All

Ages: 18 to 49 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

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20 participants in 2 patient groups

Intervention Order (Placebo - Diphenhydramine)

Other group

Description:

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 \~28°C and 30% relative humidity

Treatment:

Drug: Diphenhydramine

Drug: Placebo

Intervention Order (Diphenhydramine -Placebo)

Other group

Description:

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 \~28°C and 30% relative humidity

Treatment:

Drug: Diphenhydramine

Drug: Placebo