TY - JOUR
T1 - Citalopram enhances cocaine's subjective effects in rats
AU - Soto, Paul L.
AU - Hiranita, Takato
AU - Katz, Jonathan L.
PY - 2009/12
Y1 - 2009/12
N2 - Serotonin-selective reuptake inhibitors (SSRIs) have been shown to enhance the locomotor stimulatory, discriminative-stimulus, and convulsive effects of cocaine in rodents. A pharmacokinetic mechanism for the interaction is supported by increases in the brain levels of cocaine by fluoxetine treatment. Furthermore, the locomotor-stimulant effects of cocaine in rodents are enhanced by fluoxetine and fluvoxamine, SSRIs known to inhibit cocaine-metabolizing cytochrome P450 enzymes, whereas citalopram, an SSRI that does not inhibit P450 enzymes, does not enhance cocaine's locomotor-stimulant effects. Citalopram, however, attenuated the discriminative-stimulus effects of cocaine in squirrel monkeys trained to discriminate cocaine from saline, though it enhanced the discriminative-stimulus effects of a low dose of cocaine in rats trained to discriminate high and low doses of the drug. This study investigated the effects of citalopram on cocaine's discriminative-stimulus effects in rats trained more simply to discriminate cocaine from saline. Citalopram alone produced predominantly saline-appropriate responding, but when administered before cocaine, citalopram dose-dependently shifted the cocaine dose-response curve leftward. The present findings suggest that enhancement of cocaine's discriminative-stimulus effects may occur through a mechanism different from that underlying enhancement of cocaine's locomotor effects or that another action of citalopram selectively blocks locomotor enhancement.
AB - Serotonin-selective reuptake inhibitors (SSRIs) have been shown to enhance the locomotor stimulatory, discriminative-stimulus, and convulsive effects of cocaine in rodents. A pharmacokinetic mechanism for the interaction is supported by increases in the brain levels of cocaine by fluoxetine treatment. Furthermore, the locomotor-stimulant effects of cocaine in rodents are enhanced by fluoxetine and fluvoxamine, SSRIs known to inhibit cocaine-metabolizing cytochrome P450 enzymes, whereas citalopram, an SSRI that does not inhibit P450 enzymes, does not enhance cocaine's locomotor-stimulant effects. Citalopram, however, attenuated the discriminative-stimulus effects of cocaine in squirrel monkeys trained to discriminate cocaine from saline, though it enhanced the discriminative-stimulus effects of a low dose of cocaine in rats trained to discriminate high and low doses of the drug. This study investigated the effects of citalopram on cocaine's discriminative-stimulus effects in rats trained more simply to discriminate cocaine from saline. Citalopram alone produced predominantly saline-appropriate responding, but when administered before cocaine, citalopram dose-dependently shifted the cocaine dose-response curve leftward. The present findings suggest that enhancement of cocaine's discriminative-stimulus effects may occur through a mechanism different from that underlying enhancement of cocaine's locomotor effects or that another action of citalopram selectively blocks locomotor enhancement.
KW - Citalopram
KW - Cocaine
KW - Drug discrimination
KW - Rats
UR - http://www.scopus.com/inward/record.url?scp=73949123323&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=73949123323&partnerID=8YFLogxK
U2 - 10.1097/FBP.0b013e328333a267
DO - 10.1097/FBP.0b013e328333a267
M3 - Article
C2 - 20195220
AN - SCOPUS:73949123323
VL - 20
SP - 759
EP - 762
JO - Behavioural Pharmacology
JF - Behavioural Pharmacology
SN - 0955-8810
IS - 8
ER -