Influence of Cocaine Use on Cigarette Smoking

To the Editor.  —The potential contribution of cigarette smoking to cocaine-associated catastrophic cardiac events has been mentioned in several reports,^1,2 including an experimental study demonstrating that cigarette smoking exacerbates the deleterious effects of cocaine on myocardial oxygen supply.¹ We have written to share four recent observations by our group suggesting that combined use of cigarettes and cocaine is common among cocaine abusers, and that cocaine abusers who smoke cigarettes may place themselves at greater risk for adverse cardiac effects by using cocaine more frequently or in larger amounts than nonsmokers and by smoking at an elevated rate while under the influence of cocaine.First, we compared the point prevalence of smoking in cocaine-dependent patients (n=87) enrolled in drug-abuse treatment with a matched general-population sample (n=78); prevalence was 3.4 times greater (75% vs 22%; P<.001) in the former.³Second, among the cocaine-dependent patients in that study, smokers