Cocaine and Body Temperature: Effect of Exercise at High Ambient Temperature

Abstract

The laboratory rat has been used as an animal model to investigate the effects of cocaine on body temperature and to determine if abuse of the drug is a risk factor in the pathogenesis of exercise-induced heat stroke. Animals were trained to run on a treadmill which was enclosed so that the ambient temperature could be regulated. Exercise at ambient temperatures of 20 and 30 °C led to a similar rise in core temperature of ≈1 °C, although the starting core temperature was higher in the rats at 30°C(38.5 ± 0.10 °C compared to 37.9 ± 0.06 °C). Cocaine (20 mg/kg) led to a transient fall in core temperature in the 20 °C group; the temperature then rapidly recovered, so that after 60 min exercise there was no significant difference between these and the control animals. At the higher ambient temperature cocaine augmented the rise in core temperature during running, although the animals had regained thermal balance by 30 min and core temperature was maintained at 40.2 ± 0.13 °C until the end of the exercise period. The dopamine D₁ receptor antagonist SCH 23390 (0.1, 0.3 or 1.0 mg/kg) led to suppression of spontaneous motor activity so that the rats could be persuaded to exercise for only 30–45 min after treatment. Pretreatment with the antagonist did not affect the rise in core temperature induced by cocaine at 30 °C which again stabilized by 30 min at 40.0 ± 0.12 °C. It is concluded that toxic doses of cocaine can precipitate exercise-induced heat stroke at elevated ambient temperatures. Dopamine D₁ antagonists would not seem to offer a useful therapeutic adjunct to the management of patients who develop hyperthermia after ingestion of cocaine; the first line of treatment should be directed at lowering body temperature by physical methods.

National Athletic Trainers' Association Position Statement: Exertional Heat Illnesses

“…Athletes who take certain medications or drugs, particularly medications with a dehydrating effect, are at an increased risk for a heat illness. [101][102][103][104][105][106][125][126][127][128][129][130][131][132][133][134][135][136] Alcohol, caffeine, and theophylline at certain doses are mild diuretics. 106,137,138 Caffeine is found in coffee, tea, soft drinks, chocolate, and several over-the-counter and prescription medications.…”

Associations between short-term ambient temperature exposure and emergency department visits for amphetamine, cocaine, and opioid use in California from 2005 to 2019

“…The hyperthermic property of stimulants are well documented in animal and human studies, particularly for 3,4-Methylenedioxymethamphetamine (MDMA) and cocaine ( Liechti 2014 , Lomax and Daniel 1993 , Parrott 2012 ). Stimulants can increase heat production by increasing metabolic activity, and impair heat dissipation by reducing peripheral blood flow as well as the delayed the onset of diaphoresis ( Freedman et al 2005 , Mills et al 2004 , Rusyniak and Sprague 2005 ).…”