Intranasal Cocaine and Temperature Regulation During Exercise

Sponsor

University of Texas Southwestern Medical Center (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT05809453

Collaborator

(none)

Enrollment

Location

Arms

Anticipated Duration (Months)

0.8

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

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

Condition or Disease	Intervention/Treatment	Phase
Hyperthermia Cocaine Use Exercise	Drug: Cocaine Drug: Lidocaine	Phase 1/Phase 2

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.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

20 participants

Allocation:

Randomized

Intervention Model:

Crossover Assignment

Intervention Model Description:

We will conduct a double-blind, placebo-controlled, crossover study. Following informed consent and screening, eligible participants will be randomized to complete the cocaine or the lidocaine (placebo) trial first, with the other "agent" administered during the subsequent visit. During these experimental visits, we will first obtain "pre-drug" temperature and cardiovascular data, which will be followed by administer of cocaine or lidocaine intranasally. Participants will then enter the chamber set to warm environmental conditions. After further instrumentation in the warm environment, participants will perform mild to moderate intensity physical activity for 60 minutes. Throughout the 60 minutes of physical activity we will record body temperature and cardiovascular responses. Upon concluding the physical activity, subjects will rest while body temperature and cardiovascular responses are obtained post-physical activity.We will conduct a double-blind, placebo-controlled, crossover study. Following informed consent and screening, eligible participants will be randomized to complete the cocaine or the lidocaine (placebo) trial first, with the other "agent" administered during the subsequent visit. During these experimental visits, we will first obtain "pre-drug" temperature and cardiovascular data, which will be followed by administer of cocaine or lidocaine intranasally. Participants will then enter the chamber set to warm environmental conditions. After further instrumentation in the warm environment, participants will perform mild to moderate intensity physical activity for 60 minutes. Throughout the 60 minutes of physical activity we will record body temperature and cardiovascular responses. Upon concluding the physical activity, subjects will rest while body temperature and cardiovascular responses are obtained post-physical activity.

Masking:

Single (Investigator)

Masking Description:

Our research nurse will know whether the participant will receive cocaine or lidocaine. All others involved in the protocol, including the participant, will not know which agent they received for which trial.

Primary Purpose:

Basic Science

Official Title:

Intranasal Cocaine and Temperature Regulation During Exercise

Anticipated Study Start Date :

Jun 1, 2023

Anticipated Primary Completion Date :

Jun 1, 2025

Anticipated Study Completion Date :

Jun 1, 2025

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Cocaine Prior 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.	Drug: Cocaine Cocaine will be administered intranasally prior to entering the warm environmental conditions and performing 60 minutes of exercise.
Placebo Comparator: Lidocaine Prior 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.	Drug: Lidocaine Lidocaine will be administered intranasally prior to entering the warm environmental conditions and performing 60 minutes of exercise.

Arm

Intervention/Treatment

Experimental: Cocaine

Prior 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.

Drug: Cocaine

Cocaine will be administered intranasally prior to entering the warm environmental conditions and performing 60 minutes of exercise.

Placebo Comparator: Lidocaine

Prior 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.

Drug: Lidocaine

Lidocaine will be administered intranasally prior to entering the warm environmental conditions and performing 60 minutes of exercise.

Outcome Measures

Primary Outcome Measures

Change in core body temperature [Within 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

Change in skin temperature [Within 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 rate [Within 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
Change in cardiac output - echocardiography [Within 30 minutes before exposure to warm environmental conditions, throughout 60 minutes of exercise, and during the 30 minute recovery period.]
Cardiac output (how much blood is ejected from the heart) will be measured using echocardiography.
Change in cardiac output - rebreathing [Within 30 minutes before exposure to warm environmental conditions, throughout 60 minutes of exercise, and during the 30 minute recovery period.]
Cardiac output (how much blood is ejected from the heart) will be measured using nitrous oxide rebreathing.
Change in whole body sweat rate [Within 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 pressure [Within 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.
Perceptual questionnaire on how hot one feels [These 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"
Perceptual questionnaire on how hard one feels they are exercising [These 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"

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years to 50 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

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