Effects of cocaine, alone and in combination with task performance, on heart rate and blood pressure.

Eleven adult male subjects with histories of cocaine use participated in daily experimental sessions consisting of resting cardiovascular (heart rate, blood pressure) baseline measures followed by intranasal cocaine (4, 48 or 96 mg) administration and further cardiovascular monitoring. Subjects in Group I performed a learning task before and after cocaine administration, while subjects in Group II rested. Cocaine administration alone significantly increased heart rate up to 10 beats per minute (bpm) and mean arterial pressure (MAP) up to 15 mm/Hg. Task performance alone increased heart rate up to 8 bpm and MAP up to 10 mm/Hg. In combination, increases in heart rate up to 19 bpm and MAP up to 18 mm/Hg were observed. Thus, combinations of cocaine administration and task performance increased heart rate and blood pressure above levels observed following the occurrence of either activity alone. These results indicate the importance of understanding the effects of drugs within the environmental context in which they are taken.