Latest medical literature on prozac

Our library of drug research abstracts drawn from the medical literature is updated on a regular schedule, and you can be assured that new prozac research articles will be listed here shortly after becoming available to us.

Medical research on prozac

Personality disorders and perceived stress in major depressive disorder.

Psychiatry Res. 2008 Jun 21;
Candrian M, Schwartz F, Farabaugh A, Perlis RH, Ehlert U, Fava M
The investigation of comorbidity between major depressive disorder (MDD) and personality disorders (PDs) has attracted considerable interest. Whereas some studies found that the presence of PDs has adverse effects on the course and treatment of MDD, others have failed to demonstrate this link. These inconsistent findings suggest that specific PD comorbidity might affect the course of MDD by modulating factors that increase the overall risk of depression, including an elevated tendency to perceive stress. To investigate whether the presence of a specific PD cluster was associated with elevated levels of stress appraisal, we administered the Perceived Stress Scale (PSS) before and after treatment to 227 MDD outpatients enrolled in an 8-week open-label treatment with fluoxetine. Following treatment, multiple linear regression analyses revealed that the presence of Cluster A, but not Cluster B or C, was associated with higher levels of perceived stress, even after adjusting for baseline depression severity and PSS scores, as well as various sociodemographic variables. The presence of Cluster A PD comorbidity was uniquely associated with elevated stress appraisal after antidepressant treatment, raising the possibility that stress exacerbation might be an important factor linked to poor treatment outcome in MDD subjects with Cluster A pathology.

Fluoxetine-induced proliferation and differentiation of neural progenitor cells isolated from rat postnatal cerebellum.

Biochem Pharmacol. 2008 May 23;
Zusso M, Debetto P, Guidolin D, Barbierato M, Manev H, Giusti P
Previous studies have shown that the serotonin-reuptake inhibitor (SSRI) fluoxetine affects neural progenitors derived from postnatal cerebellum or adult hippocampus and stimulates their proliferation. In the human cerebellum, the proliferation of cerebellar granule cells (CGC) continues until the 11th postnatal month and could be influenced in infants by breastfeeding-delivered SSRIs. Current information about fluoxetine effects on postnatal cerebellar neural progenitors is limited. Here we report the characterization of fluoxetine actions on rat postnatal cerebellar neural progenitors. RT-PCR and immunostaining revealed the expression of serotonin transporter (SERT), 5HT(1A) receptors, tryptophan hydroxylase (TPH), and serotonin (5HT). Protracted in vitro fluoxetine treatment increased cell proliferation and differentiation. The proliferative effects of fluoxetine, 5HT, and the selective agonist of 5HT(1A) receptors trans-8-hydroxy-2-(N-n-propyl-N-3'-iodo-2'-propenyl)aminotetralin (8-OH-PIPAT) were abolished by the selective antagonist of 5HT(1A) receptors, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohexanecarboxamide trihydrochloride (WAY-100635). Furthermore, fluoxetine-induced activation of both the cAMP-response element-binding (CREB) protein and extracellular signal-regulated protein kinases (ERK1/2), which was abolished by the selective inhibitor of MAP kinase kinase (MEK) 1,4-diamino-2,3-dicyano-1,4-bis(2-aminophenylthio)butadiene (U0126), and increased cyclin D1 expression. All these effects were prevented by WAY-100635. Collectively, our results demonstrate that rat postnatal cerebellum contains neural progenitors capable of proliferating and differentiating in response to fluoxetine exposure, possibly through the activation of 5HT(1A) receptors. The relevance of these findings for possible SSRI effects on the developing postnatal/infant human cerebellum should be explored.

Evaluation of CSF neurotransmitters and folate in 25 patients with Rett disorder and effects of treatment.

Brain Dev. 2008 Jun 20;
Temudo T, Rios M, Prior C, Carrilho I, Santos M, Maciel P, Sequeiros J, Fonseca M, Monteiro J, Cabral P, Vieira JP, Ormazabal A, Artuch R
Background: Rett disorder (RD) is a progressive neurodevelopmental entity caused by mutations in the MECP2 gene. It has been postulated that there are alterations in the levels of certain neurotransmitters and folate in the pathogenesis of this disease. Here we re-evaluated this hypothesis. Patients and methods: We evaluated CSF folate, biogenic amines and pterines in 25 RD patients. Treatment with oral folinic acid was started in those cases with low folate. Patients were clinically evaluated and videotaped up to 6 months after therapy. Results: CSF folate was below the reference values in 32% of the patients. Six months after treatment no clinical improvement was observed. Three of the four patients with the R294X mutation had increased levels of a dopamine metabolite associated to a particular phenotype. Three patients had low levels of a serotonin metabolite. Two of them were treated with fluoxetine and one showed clinical improvement. No association was observed between CSF folate and these metabolites, after adjusting for the patients age and neopterin levels. Conclusion: Our results support that folinic acid supplementation has no significant effects on the course of the disease. We report discrete and novel neurotransmitter abnormalities that may contribute to the pathogenesis of RD highlighting the need for further studies on CSF neurotransmitters in clinically and genetically well characterized patients.

Effects of a Selective Serotonin Reuptake Inhibitor, Fluoxetine, on Counterregulatory Responses to Hypoglycemia in Healthy Man.

Diabetes. 2008 Jun 20;
Briscoe VJ, Ertl AC, Tate DB, Dawling S, Davis SN
Objective: Hypoglycemia commonly occurs in intensively treated patients with Diabetes. Repeated hypoglycemia blunts counterregulatory responses thereby increasing the risk for further hypoglycemic events. Currently, physiologic approaches to augment counterregulatory responses to hypoglycemia have not been established. Therefore the specific aim of this study was to test the hypothesis that 6 weeks administration of the selective serotonin reuptake inhibitor (SSRI) fluoxetine would amplify autonomic nervous system (ANS) and neuroendocrine counterregulatory mechanisms during hypoglycemia. Research Design and Methods: Twenty healthy (10M/10F) subjects participated in an initial single step hyperinsulinemic (9pmol/kg/min) hypoglycemic (2.9+/-0.1 mmol/l) clamp study and were then randomized to receive 6 weeks of fluoxetine (n=14) or identical placebo (n=6) in a double blind fashion. After 6 weeks, subjects returned for a second hypoglycemic clamp. Glucose kinetics were determined by 3-tritiated glucose, and muscle sympathetic nerve activity (MSNA) was measured by microneurography. Results: Despite: identical hypoglycemia (2.9+/-0.1 mmol/l) and insulinemia during all clamp studies, key ANS (epinephrine, norepinephrine, MSNA but not symptoms), neuroendocrine (cortisol) and metabolic (endogenous glucose production, glycogenolysis, lipolysis) were increased (p

Treatment emergent mania responding to valproate in a Chinese female adolescent population with eating disorders: A case series.

Eur Eat Disord Rev. 2008 Jun 20;
Tor PC, Lee EL
Eating disorders are commonly associated with depressive symptoms. In an adolescent and binge eating population fluoxetine is commonly used to treat co-morbid depression associated with eating disorders. In some patients this may precipitate treatment emergent mania (TEM). Risk factors in the adolescent population include being older, female, having a longer duration of illness, more previous mood episodes, a higher prevalence of subclinical hypothyroidism, early-onset anxiety and recent exposure to a mood-elevating agent. Diagnosis and management of these co-morbid conditions is challenging due to the overlapping symptomatology and the adverse effects of both conditions complicating pharmacological management. This is illustrated with three cases in a Chinese female adolescent population that experienced TEM while on fluoxetine and responded to valproate. Copyright (c) 2008 John Wiley & Sons, Ltd and Eating Disorders Association.

Mouse strain differences in the unpredictable chronic mild stress: a four-antidepressant survey.

Behav Brain Res. 2008 May 2;
Yalcin I, Belzung C, Surget A
There have been few comparisons of strains and antidepressants in the unpredictable chronic mild stress (UCMS) paradigm in mice. This study was undertaken to determine the influence of such factors using four antidepressants drugs including the tricyclics imipramine (20mg/(kgday)) and desipramine (10mg/(kgday)), the tetracyclic maprotiline (20mg/(kgday)) and the selective serotonin reuptake inhibitor (SSRI) fluoxetine (10mg/(kgday)) in both Swiss and BALB/c mice. A 6-week UCMS regimen induced deterioration of the coat state and decreased grooming behaviours in the splash test in BALB/c mice but not Swiss mice. The four antidepressants reversed the UCMS-induced effects in BALB/c mice in both measures. However, imipramine and fluoxetine reached significance in the splash test while desipramine and maprotiline displayed only a trend. In conclusion, these results emphasize that BALB/c mice are more sensitive than Swiss mice for studying the effects of the UCMS model as well as for testing antidepressant-like properties.

Neuronal NOS inhibitor 1-(2-trifluoromethylphenyl)-imidazole augment the effects of antidepressants acting via serotonergic system in the forced swimming test in rats.

Pharmacol Biochem Behav. 2008 May 6;
Ulak G, Mutlu O, Akar FY, Komsuoğlu FI, Tanyeri P, Erden BF
Treatment-resistant depression has necessitated new therapeutic strategies in augmenting the therapeutic actions of currently existing antidepressant drugs. The aim of this study was to investigate the possibility of synergistic interaction between 1-(2-trifluoromethylphenyl)-imidazole (TRIM), a novel neuronal nitric oxide synthase (nNOS) inhibitor and conventional antidepressants of different classes in the forced swimming test (FST) in rats. TRIM decreased the immobility time at 50 mg/kg doses in the FST in rats. Treatment with a behaviourally subeffective dose of TRIM (20 mg/kg) augmented the behavioural effect of tricyclic antidepressant imipramine, selective serotonin re-uptake inhibitor (SSRI) citalopram and fluoxetine or selective serotonin reuptake enhancer tianeptine but failed to augment the antidepressant effect of reboxetine, a noradrenaline re-uptake inhibitor, in this test. Therefore inhibition of NOS augments the effects of antidepressants acting on serotonergic system in the FST. Neither TRIM (10-50 mg/kg) nor other drug treatments affected the locomotor activity of animals. These findings are in agreement with the view that antidepressant effects or augmentation of these effects in the FST may be explained with inhibition of NOS activity and this may be a new approach in offering greater therapeutic efficacy of antidepressants acting via serotonergic system.

Synapse specific changes in serotonin signalling contribute to age-related changes in the feeding behaviour of the pond snail, Lymnaea.

J Neurochem. 2008 Jun 19;
Yeoman M, Patel B, Arundell M, Parker K, O'Hare D
This study utilised the pond snail, Lymnaea to examine the contribution that alterations in serotonergic signalling make to age-related changes in feeding. Age-related decreases in 5-HIAA levels in feeding ganglia were positively correlated with a decrease in the number of sucrose-evoked bites and negatively correlated with an increase in inter-bite interval, implicating alterations in serotonergic signalling in the aged phenotype. Analysis of the serotonergic cerebral giant cell (CGC) input to the protraction motor neurone (B1) demonstrated that fluoxetine (10-100 nM) increased the amplitude/duration of the evoked EPSP in both young and middle aged but not in old neurones, suggesting an age-related attenuation of the serotonin transporter. 5-HT evoked a concentration-dependent increase in the amplitude/duration of B1 EPSP, which was greater in old neurones compared to both young and middle aged. Conversely, the 5-HT-evoked depolarisation and conditional bursting of the swallow motor neurone (B4) were attenuated in old neurones, functions critical for a full feeding rhythm. The CGCs' ability to excite B1 was blocked by cinanserin but not by methysergide. Conversely, the CGC to B4 connection was completely blocked by methysergide and only partially by cinanserin suggesting that age-related changes may be receptor specific. In summary, synapse-specific attenuation of the CGC-B4 connection and enhancement of the CGC-B1 connection would slow the swallow phase and maintain protraction, consistent with behavioural observations.

Effect of antidepressants on melatonin metabolite in depressed patients.

J Psychopharmacol. 2008 Jun 18;
Carvalho L, Gorenstein C, Moreno R, Pariante C, Markus R
Abstract Antidepressants increase melatonin levels, but it is still unclear whether this effect is related to the improvement of depressive symptoms or to unrelated pharmacological action of antidepressants. To answer this question, the effect of antidepressants on 6-sulphatoxymelatonin (aMT6s), the main melatonin urinary metabolite, was examined in drug-free depressed patients - most of them antidepressant-naive. aMT6s was evaluated in 34 depressed patients, before and after 8 weeks of placebo (n = 12) or antidepressant (n = 22; fluoxetine, duloxetine or Hypericum perforatum). Both groups showed an improvement of depressive symptoms after treatment compared to baseline (Hamilton Depression scores): 17.0 +/- 1.4 vs. 9.0 +/- 2.8, P = 0.007 for placebo, and 18.6 +/- 1.1 vs 11.8 +/- 1.6, P < 0.001 for antidepressants). After treatment, aMT6s levels increased after antidepressants (P < 0.01), but not after placebo (P > 0.05). As depressive symptoms improved both in patients taking antidepressant and in those taking placebo, but an effect of antidepressants could only be seen in those taking antidepressants, we suggest that melatonin changes after antidepressants are more likely due to a pharmacological action of these drugs on melatonin secretion.

Management Strategies for Premenstrual Syndrome/Premenstrual Dysphoric Disorder (July/August) (CE).

Ann Pharmacother. 2008 Jun 17;
Jarvis CI, Lynch AM, Morin AK
OBJECTIVE: To evaluate the current nonpharmacologic and pharmacologic treatment options for symptoms of premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD). DATA SOURCES: Literature was obtained through searches of MEDLINE Ovid (1950-March week 3, 2008) and EMBASE Drugs and Pharmacology (all years), as well as a bibliographic review of articles identified by the searches. Key terms included premenstrual syndrome, premenstrual dysphoric disorder, PMS, PMDD, and treatment. STUDY SELECTION AND DATA EXTRACTION: All pertinent clinical trials, retrospective studies, and case reports in human subjects published in the English language were identified and evaluated for the safety and efficacy of pharmacologic and nonpharmacologic treatments of PMS/PMDD. Data from these studies and information from review articles were included in this review. DATA SYNTHESIS: Selective serotonin-reuptake inhibitors (SSRIs) have been proven safe and effective for the treatment of PMDD and are recommended as first-line agents when pharmacotherapy is warranted. Currently fluoxetine, controlled-release paroxetine, and sertraline are the only Food and Drug Administration-approved agents for this indication. Suppression of ovulation using hormonal therapies is an alternative approach to treating PMDD when SSRIs or second-line psychotropic agents are ineffective; however, adverse effects limit their use. Anxiolytics, spironolactone, and nonsteroidal antiinflammatory drugs can be used as supportive care to relieve symptoms. Despite lack of specific evidence, lifestyle modifications and exercise are first-line recommendations for all women with PMS/PMDD and may be all that is needed to treat mild-to-moderate symptoms. Herbal and vitamin supplementation and complementary and alternative medicine have been evaluated for use in PMS/PMDD and have produced unclear or conflicting results. More controlled clinical trials are needed to determine their safety and efficacy and potential for drug interactions. CONCLUSIONS: Healthcare providers need to be aware of the symptoms of PMS and PMDD and the treatment options available. Treatment selection should be based on individual patient symptoms, concomitant medical history, and need for contraception.