Cocaine HCl was infused intravenously to conscious mongrel dogs until death (0.5 mg/kg/min; 0.82 ml/min). All animals convulsed (mean convulsive dose: 12 +/- 1 mg/kg) and died approximately 42 min after the beginning of cocaine infusion (mean lethal dose: 21 +/- 2 mg/kg). All animals exhibited significant increases in arterial systolic and diastolic pressures, left ventricular pressure, cardiac output, heart rate, respiratory rate, minute volume, tidal volume, oxygen uptake, plasma glucose, blood lactate and body temperature. Statistically significant reductions from pre-drug control levels were observed in total peripheral resistance, arterial pH, and arterial pO2.