Cardiac and mood-related changes during short-term abstinence from crack cocaine: the identification of possible withdrawal phenomena.

Studies assessing withdrawal phenomenon during short-term abstinence from chronic cocaine use have been limited. Although cocaine abusers are reported to be at increased risk for cardiac disorders, little research has assessed cardiac parameters in cocaine abusers and subsequent changes in these parameters that may be associated with the discontinuation of cocaine use. In this study, we categorize 441 chronic cocaine abusers into three groups based on self-reported length of abstinence from cocaine use at entry into a trial approved by the National Institute on Drug Abuse (NIDA) assessing the use of pergolide mesylate in treating relapse and craving in crack cocaine abuse. Electrocardiogram (ECG) PR intervals were found to be correlated positively with length of abstinence, returning to normal population levels within 30 days. In addition, levels of generalized anxiety, nervousness, and heart racing were found to be correlated negatively with length of abstinence from crack cocaine. This work provides preliminary evidence of cardiac and mood-related parameters that are associated with cocaine abstinence and that may indicate specific withdrawal phenomena in chronic users. In addition, these results suggest that the risk of cardiomyopathies associated with abnormal atrial-ventricular polarization may dissipate relatively quickly in abusing individuals.