Effects of cocaine and alcohol alone and in combination on cardiovascular performance in dogs

Pharmacodynamic evaluation of the cardiovascular effects after the coadministration of cocaine and ethanol

One of the most common drug dependencies occurring with alcoholism is cocaine dependence. This combination is particularly worrisome because of the increased risk of cardiovascular events associated with their coabuse. Although it is well known that ethanol increases the cardiovascular effects of cocaine by inhibiting cocaine clearance and the formation of cocaethylene, it has also been postulated that ethanol enhances the cardiovascular effects of cocaine independent of the two latter mechanisms. In this study, we investigated the cardiovascular pharmacodynamics of the cocaine-ethanol interaction to determine whether ethanol directly enhanced the cardiovascular effects of cocaine. Dogs (n = 6) were administered cocaine alone (3 mg/kg i.v.) and in combination with ethanol (1 g/kg i.v.) on separate study days. Blood pressure, heart rate, and the electrocardiogram were monitored continuously, and blood samples were collected periodically after drug administration. Concentration-time data were fitted to a two-compartment model, and concentration-effect data were fitted to a simple E(max) model using WinNonlin software. Pharmacokinetic and pharmacodynamic parameters were compared between the two treatment phases by a paired t test. The administration of ethanol before cocaine resulted in a decrease in cocaine clearance, but there were no differences in any of the other pharmacokinetic or pharmacodynamic parameter values between the cocaine alone and cocaine plus ethanol phases. As has been demonstrated in previous animal and human studies, the clearance of cocaine was decreased by prior administration of ethanol. However, ethanol did not change the concentration-effect relationship of the cardiovascular response to cocaine administration. It is concluded from this study that ethanol does not directly enhance the cardiovascular effects of cocaine.

Cocaine-related myocardial infarction: concomitant heroin use can cloud the picture

Cocaine-related myocardial infarction is a well-known phenomenon. Concurrent heroin use can mask signs and symptoms of myocardial infarction. We discuss an unusual presentation of myocardial infarction, associated with both cocaine and heroin ("speedball") self-injection, that initially went undiagnosed.

The Effect of Alcohol on the Neuropsychological Functioning of Recently Abstinent Cocaine-dependent Subjects

Neuropsychological deficits in the areas of learning, memory, attention, and abstraction abilities have been associated with cocaine dependence, especially during the period of early abstinence. Although cocaine users tend to be multidrug users, few studies have focused on the combined effect of alcohol and cocaine on neuropsychological functioning. Consistent with prior research, results from the current study indicated that cocaine-dependent subjects showed a significantly greater degree of neuropsychological impairment as compared to controls. In addition, cocaine-dependent subjects with a history of alcohol disorder showed less memory impairment but similar impairments in attention and overall neuropsychological functioning as cocaine subjects with no such history. The vasodilatation produced by alcohol may attenuate some of the vasoconstriction and neurotoxic effects of cocaine, accounting for the fewer deficits in this group.

Effects of cocaine and caffeine alone and in combination on cardiovascular performance

BACKGROUND

With the proliferation of cocaine abuse, increased incidence of catastrophic cardiovascular events like angina pectoris, myocardial infarction, ventricular arrhythmias or sudden death are reported. Cocaine-dependent subjects commonly abuse multiple substances. Many of them drink coffee before and after cocaine use. The high frequency of simultaneous exposure to both the drugs may influence outcome of the cocaine's treatment. Cocaine and caffeine's independent effects on cardiodynamics are documented but to our knowledge combined effects of both on complete cardiovascular hemodynamics remains to be examined.

METHODS

Eighteen dogs were instrumented to pass cardiac catheters into right and left heart. The experiments were performed after they recovered from the effects of anesthesia. In phase I (30 experiments on 8 dogs), the doses were established by dose-response curve. In phases II and III, another 10 dogs were subjected to 28 experiments. They were given i.v. cocaine followed by caffeine and vice versa to study their effects on hemodynamics and coronary flow reserve.

RESULTS

Phase 1: The doses of cocaine (2 mg/kg) and caffeine (5 mg/kg) were established. Phase II: Cocaine increased heart rate, blood pressure and dP/dt but CFR decreased significantly. Caffeine administered after cocaine attenuated these effects (dP/dt decreased to 4910+/-104 from 5066+/-110 mm Hg s; p<NS). Phase III: Caffeine mildly increased hemodynamic parameters but reduced dP/dt. Cocaine's administration as the second drug had synergistic excitatory effects (dP/dt increased to 6166+/-160 from 5055+/-142 mm Hg/s; p<0.04). CFR decreased significantly.

CONCLUSION

Cocaine increased heart rate, blood pressure and dP/dt but reduced CFR. Caffeine mildly increased the hemodynamic variables but decreased CFR. Combined cocaine+caffeine attenuated the excitatory effects of cocaine significantly. A reversed drug combination i.e., caffeine+cocaine generated synergistic excitatory effects on the cardiovascular system of the dogs. CFR showed significant decrease.

Cardiovascular manifestations of substance abuse part 1: cocaine

Substance abuse with cocaine is associated with multiple cardiovascular conditions, including myocardial infarction, dissection, left ventricular hypertrophy, arrhythmias, sudden death, and cardiomyopathy. Cocaine has effects to potentiate the physiologic actions of catecholamines and has direct effects on voltage-dependent sodium ion channels related to local anesthetic properties. The effects of cocaine can be augmented with concomitant alcohol consumption. Acute myocardial ischemia caused by cocaine may be related to in situ thromboisis and/or coronary vasospasm. Treatment strategies for cocaine-induced myocardial infarction would include antiplatelet therapy, thrombolysis, and vasodilators (eg, nitrates, nifedipine). Beta-adrenergic blockers should not be used unless concomitant vasodilator therapy is given.

Patients on party drugs undergoing anesthesia

PURPOSE OF REVIEW

Drug abuse, especially with designer drugs, continues to grow, involving a wide demographic range. Consequently, anesthesiologists may be involved in the care of patients under the acute and chronic influence of a myriad of substances. In addition to the usual physiological damage to vital organs (heart, lungs, kidneys, and immune system) new evidence of permanent damage in regions of the brain responsible for memory and pain mediation is emerging. As drug use continues to increase, anesthesiologists must learn to detect drug abusing patients and avoid known interactions. This article will attempt to review the recent literature on this subject.

RECENT FINDINGS

Cocaine, marijuana, ethanol, and heroin top the list of abused drugs, alone and in combination. The combined effects of these drugs can be synergistic in creating cardiovascular instability and toxicity. Because combinations create synergy in dopamine and serotonin transmission, addiction is possibly faster, more entrenched, and more difficult to treat. Anesthesiologists are now becoming involved in many of the rapid detoxification procedures to combat/treat addiction. Only limited research has addressed the newer designer drugs, but case reports regarding hyperthermia, cerebral edema, cerebral vasospasm, and lethal interactions with commonly used medications such as beta-blockers implicate the need for awareness in anesthesia personnel.

SUMMARY

Drug abuse continues to be a major problem facing our society. Anesthesiologists encounter emergency cases in which 'party drugs' have clearly been used, and may also be anesthetizing patients in whom abuse is present but unrecognized. Understanding how illicit drugs interact with anesthetic agents is of paramount importance.