Intranasal Cocaine and Temperature Regulation During Exercise

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.

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