FLUOXETINE ALTERS THE EFFECTS OF INTRAVENOUS COCAINE IN HUMANS

Fluoxetine, a selective serotonin reuptake inhibitor, is currently bei ng evaluated as a potential treatment for cocaine abuse. This 4-week i npatient study evaluated the pharmacologic interaction between fluoxet ine and cocaine in healthy adult male volunteers (N = 5) with historie s of cocaine abuse. Oral capsules were administered daily containing e ither placebo (weeks 1 and 4) or fluoxetine in a series of ascending d oses (10, 20, 30, and 40 mg) where each dose was given for three to fo ur consecutive days. Cocaine challenge sessions were conducted twice w eekly, once at each active dose level and twice during both the placeb o and washout phases. Subjects received three ascending intravenous do ses of cocaine (0, 20, and 40 mg) 1.5 hours apart and were monitored o n physiologic and subjective measures. Cocaine alone increased heart r ate, blood pressure, and pupillary diameter and increased subjective r eports reflecting positive mood effects and drug Liking. Fluoxetine (4 0 mg) significantly decreased subjective ratings of cocaine's positive mood effects on several visual analog measures. Fluoxetine also atten uated the mydriatic effect of cocaine. No adverse physiologic interact ions between the two drugs were observed on cardiovascular measures. T hese data suggest that fluoxetine may be safely used in the presence o f cocaine use and should be investigated further as a potential pharma cotherapy for cocaine abuse.