Additive hypothermic effects of cocaine and nicardipine in guinea-pigs

1. This study investigated the thermoregulatory effects of cocaine combined with two reported antidotal treatments for acute cocaine overdosage, calcium channel blocker therapy and cold ambient temperatures. 2. Cocaine and nicardipine alone lowered the core temperature of female guinea-pigs (ambient temperature, 5 degrees C) which resulted in a drop in core temperature of approximately 2 degrees C at their highest respective doses (40 mg/kg and 50 mg/kg). 3. Nicardipine administration 30 min prior to cocaine caused an almost 2-fold drop in temperature (3.75 degrees C) relative to either drug alone. 4. The data suggest that cocaine and nicardipine produce hypothermia by different, but additive, mechanisms.