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Intranasal Cocaine and Temperature Regulation During Exercise

Phase 1
Completed
Conditions
Hyperthermia
Exercise
Cocaine Use
Interventions
Registration Number
NCT05809453
Lead Sponsor
University of Texas Southwestern Medical Center
Brief Summary

Assess the effects of intranasal cocaine on temperature regulation and whole-body sweat rate during exercise in warm environmental conditions.

Detailed Description

Previously it was shown that intranasal cocaine attenuates skin blood flow and sweating responses during passive heat stress, when compared to placebo. However, nothing is known about the effects of cocaine on whole-body temperature regulation during mild to moderate exercise in warm environmental condition.

This project will test the hypothesis that intranasal cocaine attenuates whole-body sweat rate, resulting in greater elevations in core temperature during mild to moderate exercise in warm environmental conditions.

Primary data include core temperature, skin temperatures, and whole body sweat rate. Secondary variables include cardiovascular responses, perceptions of exercise exertion and thermal comfort, and metabolic heat production. Intranasal lidocaine will be used as the placebo for cocaine. The selection of the drug administered during the first experimental trial will be randomized, with the other drug administered during the second experimental trial.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
12
Inclusion Criteria
  • 18 to 50 years of age
  • Healthy
  • Body mass index less than 31 kg/m^2
  • Speak English
  • Systolic blood pressure <140 mmHg
  • Diastolic blood pressure <90 mmHg
Exclusion Criteria
  • Subjects not in the defined age range
  • Participants who have cardiac, respiratory, neurological, and/or metabolic illnesses
  • Any known history of renal or hepatic insufficiency/disease
  • Pregnancy or breast feeding
  • Body mass less than 60 kilograms
  • Current smokers, as well as individuals who regularly smoked within the past 3 years
  • Individuals with a history of drug abuse within the past 5 years
  • Individuals who have an unexplained positive urine drug screen (e.g., some agents cause false-positive results and when agent abstained the drug screen is negative, one example could be an over the counter supplement)
  • Currently taking pain modifying medications

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
LidocaineLidocainePrior to entering the warm environmental conditions the participant will receive lidocaine intranasally at a dose no higher than 3 mg per kilogram body mass. This dose will be given only once.
CocaineCocainePrior to entering the warm environmental conditions the participant will receive cocaine intranasally at a dose no higher than 3 mg per kilogram body mass. This dose will be given only once.
Primary Outcome Measures
NameTimeMethod
Change in core body temperatureWithin 30 minutes before exposure to warm environmental conditions, throughout 60 minutes of exercise, and during the 30 minute recovery period.

Core body temperature will be measured either from a temperature sensor pill or from a rectal thermometer

Secondary Outcome Measures
NameTimeMethod
Change in whole body sweat rateWithin 30 minutes before exposure to warm environmental conditions and immediately after the 30 minute recovery period.

Whole body sweat rate will be measured by nude weight of the participant

Change in blood pressureWithin 30 minutes before exposure to warm environmental conditions, throughout 60 minutes of exercise, and during the 30 minute recovery period.

Systolic and diastolic blood pressure will be measured from a cuff placed on the upper arm.

Change in skin temperatureWithin 30 minutes before exposure to warm environmental conditions, throughout 60 minutes of exercise, and during the 30 minute recovery period.

Skin temperature will be measured from small temperature sensitive electrodes attached to the participant's skin

Change in heart rateWithin 30 minutes before exposure to warm environmental conditions, throughout 60 minutes of exercise, and during the 30 minute recovery period.

Heart rate will be measured from ECG electrodes attached to the participant

Perceptual questionnaire on how hard one feels they are exercisingThese values will be obtained throughout the 60 minutes of exercise and during the 30 minute recovery period

Subjective assessment of how hard the subject feels they are exercising

Title of scale: Rating of Perceived Exertion Borg Scale; Minimum value: 6 "No exertion at all"; Maximum value: 20 "Maximum exertion"

Perceptual questionnaire on how hot one feelsThese values will be obtained throughout the 60 minutes of exercise and during the 30 minute recovery period

Subjective assessment of how hot the subject feels.

Title of Scale: Thermal Sensation Scale; Minimum value: 0 "unbearably cold"; Maximum value: 8: "unbearably hot"

Trial Locations

Locations (1)

University of Texas Southwestern Medical Center

🇺🇸

Dallas, Texas, United States

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