citalopram Celexa
Efficacy of citalopram as a monotherapy or as an adjunctive treatment to estrogen therapy for perimenopausal and postmenopausal women with depression and vasomotor symptoms.

Soares CN, Poitras JR, Prouty J, Alexander AB, Shifren JL, Cohen LS.

Perinatal and Reproductive Psychiatry Clinical Research Program, Massachusetts General Hospital and the Department of Psychiatry, Harvard Medical School, Boston, 02114, USA. csoares partners.org

BACKGROUND: Women frequently report depressive and vasomotor symptoms during the menopausal transition. Hormone therapy has been shown to improve some of these symptoms, although its safety as a long-term treatment has been questioned. It is still unclear whether the use of antidepressants alone may alleviate menopause-related mood and vasomotor symptoms or enhance the response observed with short-term use of estrogen therapy. METHOD: Perimenopausal and postmenopausal women with depressive disorders (DSM-IV criteria) and menopause-related symptoms received treatment with 20 to 60 mg/day of citalopram alone (N = 22) or adjunctive to estrogen therapy (N = 13). Adjunctive treatment was offered to subjects who had failed to show remission of depression after 4 weeks with estrogen therapy (estradiol [E(2)]) alone. Depressive symptoms, menopause-related symptoms, and global clinical improvement were assessed at baseline and at endpoint of adjunctive treatment (8 weeks) or citalopram monotherapy (12 weeks). Remission of depression was defined as a score of < 10 on the Montgomery-Asberg Depression Rating Scale and a score of < or = 2 on the Clinical Global Impressions scale at endpoint. Data were collected from November 2000 to February 2002. RESULTS: Twelve women (92.3%) concluded the 8-week adjunctive treatment; 11 subjects (91.6%) achieved full remission of depression. Symptoms that had persisted after an initial 4-week treatment with E(2) alone (e.g., tension, anxiousness, tiredness, and difficulty in concentrating) improved significantly (p <.05). Fifteen subjects concluded the treatment with citalopram monotherapy; 13 subjects (86.6%) showed full remission of depression. Anxiety and other somatic complaints had significant improvement (p <.05), while there was a trend toward improvement in vasomotor symptoms in those receiving monotherapy (p =.06). CONCLUSION: Citalopram alone is an efficacious treatment for perimenopausal and postmenopausal women with depression. Citalopram also appears to be efficacious as an adjunctive treatment for depressed subjects who remain symptomatic after treatment with E(2) (i.e., E(2) nonremitters). The role of citalopram monotherapy for the management of vasomotor symptoms warrants further investigation.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12716252&dopt=Abstract citalopram Celexa



citalopram Celexa
The effect of acute citalopram on extracellular 5-HT levels is not augmented by lithium: an in vivo microdialysis study.

Wegener G, Linnet K, Rosenberg R, Mork A.

Institute for Basic Psychiatric Research, Department of Biological Psychiatry, DK-8240, Risskov, Denmark. wegener dadlnet.dk

A substantial number of patients do not respond sufficiently to antidepressant drugs and are therefore often co-medicated with lithium as an augmentative strategy. Since lithium has been demonstrated to affect 5-HT neurotransmission, we examined the effect of acute and subchronic lithium on 5-HT levels after a challenge with citalopram. We found that subchronic administration of lithium increases extracellular 5-HT baseline level and decreases the extracellular 5-HIAA baseline. However, we found no evidence that the effect of acute citalopram on extracellular 5-HT levels is augmented by acute or subchronic lithium.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10899300&dopt=Abstract citalopram Celexa



citalopram Celexa
Partial 5-HT1A receptor agonist properties of (-)pindolol in combination with citalopram on serotonergic dorsal raphe cell firing in vivo.

Arborelius L, Linner L, Wallsten C, Ahlenius S, Svensson TH.

Department of Clinical Neuroscience, Karolinska Hospital, Stockholm, Sweden. Lotta.Arborelius fyfa.ki.se

RATIONALE: Pindolol has been reported to shorten the onset of antidepressant action of selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs) as well as to increase their efficacy. It has been postulated that pindolol enhances the antidepressant effect of SSRIs by blocking somatodendritic 5-HT1A autoreceptors, thus antagonizing the SSRI-induced feedback inhibition of midbrain 5-HT cell firing. A recent study, however, found that pindolol suppresses the firing rate of central 5-HT cells, suggesting that the compound possesses agonistic activity at 5-HT1A autoreceptors. OBJECTIVES: The purpose of the present study was to investigate if acute administration of (-)pindolol antagonizes the decrease in firing rate of dorsal raphe 5-HT cells produced by acute treatment with the SSRI citalopram. METHODS: Extracellular recordings of single 5-HT neurons in the dorsal raphe nucleus in anaesthetized rats. RESULTS: Administration of 0.25 or 3.0 mg/kg (IV) (-)pindolol alone decreased the firing rate of a majority of the 5-HT cells studied, an effect that was reversed by the 5-HT1A receptor antagonist WAY 100635 (0.1 mg/kg, IV). Neither 0.25 nor 3.0 mg/kg (-)pindolol reversed the citalopram (0.1-0.2 mg/kg. IV)-induced suppression of 5-HT cell activity, but produced a further decrease in firing rate. In contrast, WAY100635 (0.1 mg/kg) completely reversed this effect of citalopram. Yet, pretreatment with 3.0, but not 0.25 mg/kg (-)pindolol significantly attenuated the acute inhibitory effect of citalopram on serotonergic cell firing. CONCLUSIONS: The present findings support the previous notion that (-)pindolol possesses prominent agonistic activity at somatodendritic 5-HT1A autoreceptors, but also indicate that it may possess a weak antagonistic action at these receptors.

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citalopram Celexa
Escitalopram, the S-(+)-enantiomer of citalopram, is a selective serotonin reuptake inhibitor with potent effects in animal models predictive of antidepressant and anxiolytic activities.

Sanchez C, Bergqvist PB, Brennum LT, Gupta S, Hogg S, Larsen A, Wiborg O.

Research Laboratories, H. Lundbeck A/S, Ottiliavej 9, 2500 Copenhagen, Denmark. cs lundbeck.com

OBJECTIVE: The pharmacological profile of escitalopram, the S-(+)-enantiomer of citalopram, was studied and compared with citalopram and the R-(-)-enantiomer, R-citalopram. METHODS: Inhibition of the serotonin transporter (5-HTT) was studied in COS-1 cells expressing the human 5-HTT (h-5-HTT) and in rat brain synaptosomes. In vitro selectivity was studied relative to noradrenaline transporter (NAT) and dopamine transporter (DAT) function in rat brain synaptosomes, and affinities for other binding sites were determined. In vivo 5-HT activity was measured as inhibition of neuronal firing rate in rat dorsal raphe nucleus (DRN) and enhancement of 5-hydroxytryptophan (5-HTP)-induced behaviour (mouse and rat). Furthermore, studies were conducted in models of antidepressant (mouse forced-swim test), anxiolytic [foot-shock-induced ultrasonic vocalization (USV) in adult rats and mouse black and white box] and anti-aggressive activity (socially isolated mice). RESULTS: Escitalopram inhibited 5-HTT functions approximately 2 times more potently than citalopram and at least 40 times more potently than R-citalopram. Escitalopram showed insignificant activity at other monoamine transporters and 144 other binding sites. Escitalopram inhibited 5-HT neuronal firing in DRN and potentiated 5-HTP-induced behaviours more potently than citalopram; R-citalopram was inactive. Escitalopram and citalopram, but not R-citalopram, reduced forced-swimming-induced immobility and facilitated exploratory behaviour in the black and white box. Escitalopram and citalopram inhibited USV potently; R-citalopram was several times less potent. Escitalopram, citalopram and R-citalopram inhibited aggressive behaviour weakly. Escitalopram and citalopram had very potent anti-aggressive effects when co-administered with l-5-HTP. CONCLUSION: Escitalopram is a very selective 5-HT reuptake inhibitor. It is more potent than its racemate citalopram and is effective in animal models predictive of antidepressant and anxiolytic activities.

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citalopram Celexa
Endogenous serotonin enhances the release of dopamine in the striatum only when nigro-striatal dopaminergic transmission is activated.

Lucas G, De Deurwaerdere P, Porras G, Spampinato U.

Laboratoire de Neuropsychobiologie des Desadaptations, UMR-CNRS 5541, Universite Victor Segalen Bordeaux 2, Boite Postale 31, 146, rue Leo Saignat, 33076 Bordeaux Cedex, France.

In this study, we use in vivo microdialysis to investigate the influence of endogenous serotonin (5-HT) on striatal dopamine (DA) and 5-hydroxyidoleacetic acid (5-HIAA) efflux in both basal and activated conditions. The selective serotonin reuptake inhibitors citalopram and fluoxetine were used to mobilize endogenous 5-HT.In halothane-anaesthetized rats, citalopram (5 mg/kg, i.p.), administered either alone or in combination with the 5-HT(1A) receptor antagonist WAY 100635 (0.1 mg/kg, s.c.), while reducing striatal 5-HIAA outflow (-25 and -15%, respectively), had no effect on basal DA output. When locally applied into the striatum, citalopram had no effect at 1 microM concentration, but enhanced DA release after its perfusion at 25 and 100 mircroM concentrations (+27% and +67%, respectively). However, the injection of the neurotoxin 5,7-dihydroxytryptamine into the dorsal raphe nucleus, which markedly depleted 5-HT in the striatum, failed to modify the effect of 25 microM citalopram.In freely-moving rats, the intrastriatal infusion of citalopram or fluoxetine (1 microM each), had no effect on its own, but significantly enhanced the increase in DA outflow induced by the subcutaneous administration of 0.01 mg/kg haloperidol (+31% and +30% for citalopram and fluoxetine, respectively).These findings indicate that, in the striatum, endogenous 5-HT has no influence on DA release under basal conditions, but positively modulates DA outflow when nigro-striatal DA transmission is activated.

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citalopram Celexa
Inhibition of 5-hydroxytryptamine reuptake by the antidepressant citalopram in the locus coeruleus modulates the rat brain noradrenergic transmission in vivo.

Mateo Y, Ruiz-Ortega JA, Pineda J, Ugedo L, Meana JJ.

Department of Pharmacology, University of the Basque Country, E-48940 Leioa, Bizkaia, Spain.

The in vivo effect of the serotonin (5-HT) reuptake inhibitor antidepressant citalopram, administered in the locus coeruleus (LC), on noradrenergic transmission was evaluated in the rat brain. In dual-probe microdialysis assays, citalopram (0.1-100 microM), in a concentration-dependent manner, increased extracellular noradrenaline (NA) in the LC and simultaneously decreased extracellular NA in the cingulate cortex (Cg). These effects of citalopram were abolished by pretreatment with the 5-HT synthesis inhibitor p-chlorophenylalanine (400 mg/kg, i.p.). When the alpha(2)-adrenoceptor antagonist RS79948 (1 microM) was perfused in the LC, local citalopram increased NA dialysate in the LC but no longer modified NA dialysate in the Cg. In electrophysiological experiments, the administration of citalopram (100 microM) in the LC by reversal dialysis, decreased the firing rate of LC neurones. The results demonstrate in vivo that local administration of citalopram in the LC leads to a decreased release of NA in the Cg. This modulation seems to be the result of an increase in NA concentration in the LC and the subsequent inhibition of LC neurones via alpha(2)-adrenoceptors. The effects of citalopram are dependent on the presence of endogenous 5-HT in the LC.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10963747&dopt=Abstract citalopram Celexa



citalopram Celexa
Blockade of serotonin 5-HT1B and 5-HT2A receptors suppresses the induction of locomotor activity by 5-HT reuptake inhibitors, citalopram and fluvoxamine, in NMRI mice exposed to a novel environment: a comparison to other 5-HT receptor subtypes.

Millan MJ, Veiga S, Girardon S, Brocco M.

Psychopharmacology Department, Institut de Recherches Servier, Centre de Recherches de Croissy, 125 Chemin de Ronde, 78290 Croissy/Seine, France. mark.millan fr.netgrs.com

RATIONALE: Though 5-HT plays an important role in the modulation of motor function, which is perturbed in depressive states, little is known concerning the influence of serotonin reuptake inhibitors (SSRIs) on locomotor activity (LA). Recently, we demonstrated that SSRIs, such as citalopram, enhance LA in mice exposed to a novel environment. OBJECTIVES: This study examined the role of multiple classes of 5-HT receptor in citalopram-induced LA. METHODS: The most selective antagonists currently available were used. RESULTS: Citalopram-induced LA was dose-dependently attenuated by the 5-HT1B/1D receptor antagonists, S18127, GR125,743 and GR127,935, and by the selective 5-HT1B antagonist, SB224,289, but unaffected by the selective 5-HT1A antagonist, WAY100,635. The selective antagonists at 5-HT2A receptors, MDL100,907 and SR46,349 also dose-dependently attenuated induction of locomotion by citalopram, whereas the 5-HT2B antagonist, SB204,741, and the 5-HT2B/2C antagonist, SB206,553 were ineffective. Further, the selective 5-HT2C antagonist, SB242,084, potentiated the response to citalopram. Selective antagonists at 5-HT3 (ondansetron), 5-HT4 (GR125,487), 5-HT6 (SB271,046) and 5-HT7 (SB269,970) receptors did not significantly modify the action of citalopram. Underpinning these findings, SB224,289, GR125,743, MDL100,907 and SR46,349 likewise attenuated induction of locomotion by a further SSRI, fluvoxamine. CONCLUSIONS: The locomotor response to SSRIs of mice exposed to a novel environment is mediated via 5-HT1B and 5-HT2A receptors. In view of the importance of motor function to the etiology and treatment of depression, the significance of these observations to the clinical actions of SSRIs will be of interest to elucidate.

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citalopram Celexa
The use of citalopram in resistant cataplexy.

Thirumalai SS, Shubin RA.

Huntington Hospital Sleep Disorders Center, 100 West California Boulevard, CA 91107, Pasadena, USA

Background: Cataplexy is a disabling component of the narcolepsy tetrad that is sometimes resistant to standard treatment.Case reports: Three of our patients with narcolepsy, including one who had post-traumatic narcolepsy, suffered from intractable cataplexy with failure of treatment with established drugs due to unacceptable side-effects.Results: We explored the use of citalopram (Celexa), the newest and most specific of the serotonin reuptake inhibitors, and were successful in treating cataplexy without significant side-effects. Stimulant drugs remained necessary for controlling symptoms of excessive drowsiness.Conclusions: Citalopram was effective in relieving the symptoms of resistant cataplexy in out patients.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11040464&dopt=Abstract citalopram Celexa