Combined effects of cocaine and nicotine on
cardiovascular performance in a canine model

Mehta MC, Jain AC, Billie MD.
Department of Medicine, Section of Cardiology,
West Virginia University School of Medicine,
Robert C. Byrd Health Sciences Center,
Morgantown 26506-9157, USA.
Clin Cardiol 2001 Sep;24(9):620-6


BACKGROUND: With the proliferation of cocaine abuse, increased incidence of catastrophic cardiovascular events such as angina pectoris, myocardial infarction, ventricular arrhythmias, or sudden death are reported. Many of these patients also smoke cigarettes before and after cocaine use, leading to a high frequency of simultaneous exposure to both drugs. Cocaine's and nicotine's independent effects on cardiodynamics are well documented, but combined effects of both on complete cardiovascular hemodynamics remain unknown. HYPOTHESIS: The study aimed to determine whether these effects are additive, synergistic, or antagonistic and was therefore designed to investigate the cardiovascular changes produced as a result of combined administration of cocaine and nicotine in a canine model. METHODS: Initially, in phase 1, 30 experiments were performed to study the dose-response curve of both drugs. In phase II and III, 12 dogs were subjected to 30 experiments. In phase II, cocaine was given intravenously (IV) followed by nicotine. In phase III, sequence of drug administration was reversed to study the effects on hemodynamics and coronary artery blood flow reserve. RESULTS: Hemodynamic parameters observed were Phase I: Dose-response curve established the IV bolus dose of cocaine 2 mg/kg and nicotine 50 microg/kg. Phase II: Cocaine increased heart rate, blood pressure, and dP/dt, but nicotine administration after cocaine produced marked significant synergistic excitatory effects: dP/dt increased from 1,810 +/- 210 to 6,300 +/- 460 (p < 0.003). Phase III: Nicotine significantly increased heart rate, mean arterial pressures, left ventricular end-diastolic pressure, pulmonary artery, pulmonary capillary wedge, and right atrial pressures. Nicotine increased dP/dt (1,810 +/- 192 to 5,000 +/- 160 mmHg/s; p < 0.004). These excitatory effects of nicotine were attenuated by cocaine when administered as a second drug (dP/dt decreased to 1,925 +/- 144 from 5,000 +/- 160 mmHg/s;p < 0.004). CONCLUSIONS: Cocaine, when administered alone, caused increase in heart rate, blood pressure, and dP/dt, but nicotine showed a significant increase in all the hemodynamic parameters. Both drugs reduced coronary blood flow reserve. In combination, cocaine plus nicotine administration had synergistic excitatory effects in dogs. A reversed drug combination, that is, nicotine plus cocaine, attenuated the excitatory effects of nicotine.

Prenatal cocaine
Dopaminergic flies?
Dopaminergic agents
Cocaine immunization
The coke-craving brain
Cocaine, nicotine and dopamine
Freebasing flies go hyperkinetic
Cocaine, alcohol and cocaethylene
Cocaethylene and cocaine dependence

01 02 03 04 05 06 07 08 09 10 11 12
13 14 15 16 17 18 19 20 21 22 23 24

Future Opioids
BLTC Research
Wirehead Hedonism
Utopian Pharmacology
The Hedonistic Imperative
When Is It Best To Take Crack Cocaine?

swan image
The Good Drug Guide
The Responsible Parent's Guide
To Healthy Mood Boosters For All The Family