Allergic Rhinitis, Diphenhydramine Causing Adverse Effects in Therapeutic Use, Hyperthermia, Sweating
Conditions
Keywords
thermoregulation, diphenhydramine, anticholinergic, sweating
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.
Interventions
DRUGPlacebo
A placebo pill (i.e., sugar) will be consumed 2 h before intervention.
DRUGDiphenhydramine
Extra strength Benadryl (DIN 02470144) will be consumed 2 h before intervention
Sponsors
Lakehead University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
Double-blind
Eligibility
Sex/Gender
ALL
Age
18 Years to 49 Years
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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 |
Countries
Canada
Outcome results
None listed