Posted by ed_uk on August 15, 2005, at 6:27:53
In reply to Paroxetine vs escitalopram, posted by ed_uk on August 15, 2005, at 5:51:25
I don't like disagreeing with myself but..............
Pharmacol Biochem Behav. 2003 Jul;75(4):903-7. Related Articles, Links
R-citalopram counteracts the effect of escitalopram in a rat conditioned fear stress model of anxiety.
Sanchez C, Gruca P, Bien E, Papp M.
Neuropharmacological Research, H. Lundbeck A/S, Copenhagen-Valby, Denmark. cs@lundbeck.com
S-citalopram (escitalopram) mediates the serotonin reuptake inhibitory effect of the racemate, R,S-citalopram. The effect of escitalopram (0.5-3.9 mg/kg) was investigated in a rat conditioned fear stress model of anxiety and compared to the effects of R-citalopram (1.0-7.8 mg/kg), R,S-citalopram (4.0 and 8.0 mg/kg), and escitalopram (2.0 mg/kg)+R-citalopram (7.8 mg/kg). Diazepam (0.95 mg/kg) and buspirone (4.6 mg/kg) were included as positive controls. During an acquisition session, rats were allowed to freely explore a novel cage for 9 min. During that time, they received two inescapable footshocks through an electrifiable grid floor. Groups of nonshocked control rats were run in parallel. During an expression session on the next day, rats were treated with drug or vehicle 30 min before they were reintroduced into the test cage for a 9-min period this time without receiving footshocks and the total distance travelled was recorded. The distance travelled by vehicle-treated rats was markedly suppressed compared to a vehicle-treated group of nonshocked controls. Escitalopram produced a dose-dependent inhibition of the conditioned suppression of exploratory behaviour (minimal effective dose 1.0 mg/kg). Interestingly R,S-citalopram 4.0 and 8.0 mg/kg produced significantly smaller effect than escitalopram 2.0 and 4.0 mg/kg, receptively. R-citalopram, 7.8 mg/kg, produced a significant effect. However, in spite of this, R-citalopram (7.8 mg/kg) significantly inhibited the effect of escitalopram (2.0 mg/kg). The activity in drug-treated nonshocked groups was similar to the vehicle-treated group, except for the buspirone-treated group where a significant reduction was observed. The finding that R-citalopram inhibits the effect of escitalopram may be relevant to the improved clinical efficacy seen with escitalopram compared to R,S-citalopram in the treatment of anxiety and depression.
Eur J Pharmacol. 2003 Mar 19;464(2-3):155-8.
R-citalopram attenuates anxiolytic effects of escitalopram in a rat ultrasonic vocalisation model.
Sanchez C.
Neuropharmacological Research, H. Lundbeck A/S, Ottiliavej 9, DK 2500 Copenhagen-Valby, Denmark. cs@lundbeck.com
Escitalopram mediates the serotonin reuptake inhibitory effect of citalopram. To investigate the potential interactive effects between escitalopram and R-citalopram, they were studied at standard and elevated serotonin levels in a model predictive of anxiolytic activity (inhibition of footshock-induced ultrasonic vocalisation in adult rats). At standard levels, citalopram partially inhibited (64%) and escitalopram abolished (97%) vocalisation. Co-treatment with L-5-hydroxytryptophan resulted in complete inhibition with citalopram and a substantially enhanced response to escitalopram, while R-citalopram increased the vocalisation significantly. Furthermore, R-citalopram attenuated the effect of escitalopram. These findings may be relevant to the enhanced clinical efficacy seen with escitalopram compared to citalopram.
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I found paroxetine more sedating than citalopram, I don't want to take it again. Citalopram helps my anxiety but it's been getting worse lately. Perhaps I should try escitalopram. It's £6.50 whatever I get a prescription for. I might as well try it.
poster:ed_uk
thread:541835
URL: http://www.dr-bob.org/babble/20050811/msgs/541840.html