The multifaceted effects of fluoxetine treatment on cognitive functions.

Fluoxetine, the prototypical selective serotonin reuptake inhibitor (SSRI), is widely used to treat major depressive disorder (MDD) and a variety of other central nervous system conditions, primarily due to its established clinical safety profile. Although its efficacy in treating depression is well-recognized, the impact of fluoxetine on cognitive functions remains inconsistent and elusive. In this review, we first examine the well-substantiated biological mechanisms underlying fluoxetine's antidepressant effects, which include serotonin reuptake inhibition and activation of TrkB receptors-key to brain-derived neurotrophic factor (BDNF) signaling. Subsequently, we delve into the cognitive side effects observed in both preclinical and clinical studies, affecting domains such as memory, attention, and executive functions. While certain studies indicate cognitive improvements in patients with underlying disorders, there is also evidence of negative effects, influenced by variables like gender, duration of treatment, age, disease pathology, and the specifics of cognitive testing. Significantly, the negative cognitive outcomes reported in preclinical research often involve healthy, non-diseased animals. This review underscores the necessity for heightened caution in fluoxetine prescription and further investigation into its potentially detrimental cognitive effects, even when used prophylactically.

Análisis del conocimiento sobre los inhibidores selectivos de la recaptura de serotonina (ISRS) en el manejo de la depresión por médicos residentes y concurrentes de clínica médica de 5 hospitales de CABA / Review of the Knowledge on Selective Serotonin Reuptake Inhibitors (SSRIs) for Depression Management by Resident and Intern Physicians of the Medical Clinic of 5 Hospitals in CABA

Introducción: la depresión es un trastorno cada vez más prevalente alrededor del mundo. Los médicos generales son los profesionales de la salud más consultados por pacientes deprimidos. Más del 70% de los pacientes con depresión son vistos por médicos generales y no por especialistas en Psiquiatría. Según estudios realizados en Buenos Aires, más del 25% de los pacientes internados en Servicios de Clínica Médica en hospitales generales presenta depresión. Estos pacientes suelen ser atendidos y seguidos por médicos en formación, sean residentes o concurrentes de Clínica Médica. El objetivo del trabajo fue analizar el conocimiento sobre los inhibidores selectivos de la recaptura de serotonina (ISRS) que tienen los médicos residentes y concurrentes de Clínica Médica de 5 hospitales de la Ciudad Autónoma de Buenos Aires (CABA) y describir el tratamiento de un paciente depresivo por ellos. Material y métodos: se realizó un estudio descriptivo de corte transversal con un muestreo de tipo no probabilístico. Se utilizó como instrumento de medición un cuestionario semiestructurado organizado en dos secciones, una de datos demográficos que permiten caracterizar la muestra. La otra, de 15 ítems, explora los conocimientos sobre los ISRS y el tratamiento de la depresión. Dicho cuestionario fue revisado por 4 expertos. El instrumento es anónimo. Se aplicó a 59 médicos en formación en Clínica Médica, residentes y concurrentes, de 5 hospitales de la CABA, que participaron de forma voluntaria, durante el período agosto-septiembre de 2022. Resultados: la mayoría de los médicos en formación en Clínica Médica no tratan cuadros depresivos y, ante un paciente deprimido, solicitan la evaluación por un especialista en Salud Mental. Solo un 6,8% lo medica con un antidepresivo. Más del 75% de la muestra refiere recordar los conocimientos que tiene sobre de los ISRS de la cursada de Farmacología y un 13,6 de la cursada de Psiquiatría en la Facultad de Medicina. Conclusión: se observa un conocimiento deficitario sobre los ISRS en médicos residentes y concurrentes de Clínica Médica. Se considera necesario reforzar la formación sobre depresión y manejo de antidepresivos durante la residencia/concurrencia de Clínica Médica. (AU)

Introduction: depression is an increasingly common disorder around the world. General practitioners are the most frequently consulted health professionals by depressed patients. More than 70% of all depressed patients receive treatment by general practitioners and not by psychiatric specialists. According to studies conducted in Buenos Aires, more than 25% of all patients admitted to the Clinical Services in public hospitals present depression. These patients are usually under the care and follow-up of clinical trainee physicians, residents, or interns.This study aimed to analyze the knowledge about selective serotonin reuptake inhibitors (SSRIs) of clinical trainee residents and interns in five hospitals in the Ciudad Autónoma de Buenos Aires (CABA) and to describe their treatment of a depressive patient. Material and methods: we conducted a descriptive cross-sectional study with a non-probabilistic sampling. We used a semi-structured questionnaire arranged into two sections as a measuring tool. One, with demographic data to describe the sample. The other, with 15 items, explores respondents' knowledge of SSRIs and the treatment of depression. Four experts reviewed the questionnaire, which was anonymous. We applied it to 59 clinical medical trainees, residents, and interns from five CABA hospitals who volunteered to participate during August-September 2022. Results: most clinical trainees do not treat depressive conditions and, when confronted with a depressed patient, request an assessment by a Mental Health specialist. Only 6.8% medicate the patient with an antidepressant. More than 75% of the sample reported remembering their knowledge of SSRIs from the Pharmacology course and 13.6% from the Psychiatry course at the School of Medicine. Conclusion: there is a deficient knowledge about SSRIs in trainee residents and interns of Clínica Médica. We believe it is necessary to reinforce training on depression and management of antidepressants during residency/internship practice in Clínica Médica. (AU)

Consumption and ocurrence of antidepressants (SSRIs) in pre- and post-COVID-19 pandemic, their environmental impact and innovative removal methods: A review.

Selective serotonin reuptake inhibitors (SSRIs) are pharmaceuticals whose consumption has increased significantly. They are prescribed as first-line treatment in mental disorders such as depression, obsessive-compulsive disorder, phobias, and anxiety; also, they are indicated as adjuvants in diseases such as fibromyalgia and bulimia nervosa. In addition to being linked to the illegal market to be consumed as recreational drugs. The relevance of this review lies in the fact that worldwide consumption has increased significantly during the COVID-19 pandemic, due to the depression and anxiety that originated in the population. As a consequence of this increase in consumption, concentrations of SSRIs in the environment have increased, and these have become a relevant issue for toxicologists due to the effects that they could generate in different organisms, both aquatic and terrestrial. For this reason, the objective of this article was to do a critical evaluation of the existing data on the characteristics and physicochemical properties of SSRIs, consumption data during the COVID-19 pandemic, its occurrence in the environment and the reports of toxic effects that have been generated in different organisms; we also conclude with an updated review of different methods that have been used for their removal. With this analysis, it can be concluded that, despite SSRIs are pharmaceutical products widely studied since their launching to the market, still currently under investigation to clarify their mechanisms of action to understand the different effects on the organisms, adverse reactions, as well as possible toxicological effects on non-target organisms. On the other hand, it has been proven that although it is already possible to eliminate a significant percentage of SSRIs in the laboratory, due to their physicochemical characteristics and their behavior in complex mixtures in the environment, they have not yet been eradicated, showing a persistence in the soil, subsoil and surface waters of the entire planet that may represent a future risk.

Neonatal fluoxetine exposure modulates serotonergic neurotransmission and disturb inhibitory action of serotonin on food intake.

The neurotransmitter serotonin (5-HT) acts as an important regulator of the critical neurodevelopmental processes and thus alterations in 5-HT signaling early promotes permanent structural and functional changes in brain. The selective serotonin reuptake inhibitors (SSRIs), as fluoxetine and citalopram, blocking serotonin transporter (SERT) at the presynaptic neuron, which regulates extracellular 5-HT levels. Evidence suggests that the exposure to SSRIs in the neurodevelopmental period may alters 5-HT signaling sensitivity on food intake control. The aim of the present study was to evaluate the effects of neonatal exposure to fluoxetine on molecular and cellular components of the serotonergic system and food intake control in young animals. Methods: The animals were divided according to experimental manipulation, Fluoxetine Group (FG): male pups received application of fluoxetine (10 mg/kg, 10 µL/g) and Saline Group (SG): male pups received saline application (0.9% NaCl, 10 µL/g), both throughout lactation (PND1-PND21). They evaluated body weight, food intake, SERT gene and protein expression, serotonin content in the hypothalamus. The neonatal exposure to fluoxetine promoted reduction in body weight, disturb the serotonin hypophagic response, and increase the serotonin and SERT hypothalamic in young animals. We conclude that the changes of components of the serotonergic system by neonatal exposure to fluoxetine may be responsible for disturb the inhibitory action of serotonin on food intake.

Autolesión no suicida en adolescentes peruanas: Una aproximación diagnóstica y psicopatológica / Non suicidal self-injury in Peruvian adolescents

Una aproximación diagnóstica y psicopatológica a la autolesión no suicida es planteada a partir de la recolección de datos de un grupo de diez adolescentes peruanas que sufrían esta patología. Se revisan las aproximaciones del DSM 5 a este diagnóstico, las que dan lugar a su configuración como una entidad que requiere mayor estudio para ser considerada como independiente de la sintomatología del trastorno límite de personalidad. Se formulan algunas tesis acerca de su psicopatología y las características que la singularizan frente a ese trastorno y la llamada conducta suicida. A partir de una formulación cognitivo-conductual, se examina el papel de esta sintomatología autolesiva como refuerzo automático y social, tanto en su vertiente positiva como la negativa. Ulteriormente se toman en cuenta las once creencias irracionales de Ellis como un instrumento para dilucidar la adaptación a la realidad de las pacientes que conformaron el grupo explorado. Finalmente se esbozan algunos alcances en torno a la terapia dialéctico-conductual de Linehan, mentalizing de Bateman y el uso del aripiprazol y los inhibidores selectivos de recaptación de serotonina (ISRS) en estos casos.

A psychopathological and diagnostic approach regarding non suicidal self-injury is proposed as a result of an exploratory study of a group of ten Peruvian adolescents suffering that condition. The DSM 5 status for this category is taken into account, as well as its relationship with entities like suicidal behavior and the borderline personality disorder diagnosis. On the basis of a cognitive-behavioral formulation, the meaning of this self damaging pathology in terms of automatic and social reinforcement, both positive and negative, is elucidated in order to clarify further developments. One of them being the use of Ellis’ irrational beliefs as a tool to evaluate the sense of reality of the patients. Some comments about Linehan’s dialectical behavioral psychotherapy, Bateman’s mentalizing and aripiprazole or selective serotonine reuptake inhibitors (SSRIs) in the treatment of these patients are proposed.

Are the antiplatelet and profibrinolytic properties of selective serotonin-reuptake inhibitors relevant to their brain effects?

The serotonin transporter (SERT) is found in neuron and platelet membranes. Selective serotonin-reuptake inhibitors (SSRIs) are widely prescribed for severe depression. They may at least partly counteract the effects of serotonin on the vascular biology system, can lower agonists-induced platelet activation, aggregation and procoagulant activity in vitro, thus modulating platelet thrombogenicity. Other effects, such as those mediated through PAI-1 modulation, may indirectly influence neurobiology-relevant mechanisms involved in depression. Patients receiving SSRIs are at increased bleeding risk and decreased risk of arterial occlusive events, such as myocardial infarction, compared to those using non-SSRI antidepressants. The objectives of this review were to highlight antiplatelet and profibrinolytic properties of SSRIs and discuss the potential role of these activities in the context of SSRI brain effects.

Peripheral and spinal 5-HT receptors participate in the pronociceptive and antinociceptive effects of fluoxetine in rats.

The role of 5-HT receptors in fluoxetine-induced nociception and antinociception in rats was assessed. Formalin produced a typical pattern of flinching and licking/lifting behaviors. Local peripheral ipsilateral, but not contralateral, pre-treatment with fluoxetine (0.3-3 nmol/paw) increased in a dose-dependent fashion 0.5% formalin-induced nociception. In contrast, intrathecal pretreatment with fluoxetine (0.3-3 nmol/rat) prevented nociception induced by formalin. The peripheral pronociceptive effect of fluoxetine was prevented by the 5-HT2A (ketanserin, 3-10 pmol/paw), 5-HT2B (3-(2-[4-(4-fluorobenzoyl)-1-piperidinyl]ethyl)-2,4(1H,3H)-quinazolinedione(+) tartrate, RS-127445, 3-10 pmol/paw), 5-HT2C (8-[5-(2,4-dimethoxy-5-(4-trifluoromethylphenylsulphonamido) phenyl-5-oxopentyl]1,3,8-triazaspiro[4.5] decane-2,4-dione hydrochloride, RS-102221, 3-10 pmol/paw), 5-HT3 (ondansetron, 3-10 nmol/paw), 5-HT4 ([1-[2-methylsulphonylamino ethyl]-4-piperidinyl]methyl 1-methyl-1H-indole-3-carboxylate, GR-113808, 3-100 fmol/paw), 5-HT6 (4-iodo-N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]benzene-sulfonamide hydrochloride, SB-258585, 3-10 pmol/paw) and 5-HT7 ((R)-3-(2-(2-(4-methylpiperidin-1-yl) ethyl) pyrrolidine-1-sulfonyl) phenol hydrochloride, SB-269970, 0.3-1 nmol/paw), but not by the 5-HT1A (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinylcyclohexanecarboxamide maleate, WAY-100635, 0.3-1 nmol/paw), 5-HT1B/1D (N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)-1,1'-biphenyl-4-carboxamide hydrochloride hydrate, GR-127935, 0.3-1 nmol/paw), 5-HT1B (1'-methyl-5-[[2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)biphenyl-4-yl]carbonyl]-2,3,6,7-tetrahydrospiro[furo[2,3-f]indole-3,4'-piperidine hydrochloride, SB-224289, 0.3-1 nmol/paw), 5-HT1D (4-(3-chlorophenyl)-α-(diphenylmethyl)-1-piperazineethanol hydrochloride, BRL-15572, 0.3-1nmol/paw) nor 5-HT5A ((N-[2-(dimethylamino)ethyl]-N-[[4'-[[(2-phenylethyl)amino]methyl][1,1'-biphenyl]-4-yl]methyl]cyclopentanepropanamide dihydrochloride, SB-699551, 1-3 nmol/paw), receptor antagonists. In marked contrast, the spinal antinociceptive effect of fluoxetine was prevented by the 5-HT1A (WAY-100635, 0.3-1 nmol/rat), 5-HT1B/1D (GR-127935, 0.3-1 nmol/rat), 5-HT1B (SB-224289, 0.3-1 nmol/rat), 5-HT1D (BRL-15572, 0.3-1 nmol/rat) and 5-HT5A (SB-699551, 1-3 nmol/rat), but not by the 5-HT2A (ketanserin, 3-10 pmol/rat), 5-HT2B (RS-127445, 3-10 pmol/rat), 5-HT2C (RS-102221, 3-10 pmol/rat), 5-HT3 (ondansetron, 3-10 nmol/rat), 5-HT4 (GR-113808, 3-100 fmol/rat), 5-HT6 (SB-258585, 3-10 pmol/rat) nor 5-HT7 (SB-269970, 0.3-1 nmol/rat), receptor antagonists. These results suggest that fluoxetine produces nociception at the periphery by activating peripheral 5-HT2A/2B/2C/3/4/6/7 receptors. In addition, intrathecal fluoxetine produces antinociception by activation of spinal 5-HT1A/1B/1D/5A receptors.

A proposal for refining the forced swim test in Swiss mice.

The forced swim test (FST) is a preclinical test to the screening of antidepressants based on rats or mice behaviours, which is also sensitive to stimulants of motor activity. This work standardised and validated a method to register the active and passive behaviours of Swiss mice during the FST in order to strength the specificity of the test. Adult male Swiss mice were subjected to the FST for 6 min without any treatment or after intraperitoneal injection of saline (0.1 ml/10 g), antidepressants (imipramine, desipramine, or fluoxetine, 30 mg/kg) or stimulants (caffeine, 30 mg/kg or apomorphine, 10mg/kg). The latency, frequency and duration of behaviours (immobility, swimming, and climbing) were scored and summarised in bins of 6, 4, 2 or 1 min. Parameters were first analysed using Principal Components Analysis generating components putatively related to antidepressant (first and second) or to stimulant effects (third). Antidepressants and stimulants affected similarly the parameters grouped into all components. Effects of stimulants on climbing were better distinguished of antidepressants when analysed during the last 4 min of the FST. Surprisingly, the effects of antidepressants on immobility were better distinguished from saline when parameters were scored in the first 2 min. The method proposed here is able to distinguish antidepressants from stimulants of motor activity using Swiss mice in the FST. This refinement should reduce the number of mice used in preclinical evaluation of antidepressants.

Acatisia associada à bromoprida em um paciente deprimido usando fluvoxamina / Akathisia associated with bromopride in a depressed patient using fluvoxamine

CONTEXTO: A acatisia é definida clinicamente como uma sensação de agitação associada à necessidade de produção de movimentos, comumente deflagrada por bloqueadores dopaminérgicos, como os neurolépticos, podendo ocorrer também durante o tratamento com inibidores seletivos de recaptação de serotonina. É possível que drogas não psiquiátricas que bloqueiem receptores dopaminérgicos, como a bromoprida, possam causar sintomas extrapiramidais. OBJETIVOS: Descrever um desfecho desfavorável caracterizado por acatisia em um paciente depressivo previamente estabilizado com fluvoxamina, após usar bromoprida. MÉTODOS: Descrição de um caso. RESULTADOS: Sr. J., paciente deprimido de 47 anos, estava estabilizado com fluvoxamina 200 mg por dia. Iniciou abruptamente com quadro de inquietação e necessidade de produzir movimentos voluntariamente a fim de aliviar esse desconforto. Há quatro dias havia iniciado o uso de bromoprida 30 mg por dia para tratamento de dispepsia. A suspensão da bromoprida promoveu alívio imediato dos sintomas. CONCLUSÃO: A bromoprida, um bloqueador dopaminérgico, pode ter deflagrado acatisia em um paciente em uso de fluvoxamina. Os mecanismos farmacológicos relacionados a esse desfecho são discutidos.

BACKGROUND: Akathisia is clinically defined as a sensation of restlessness associated to a necessity to produce movements, commonly triggered by dopaminergic blockers, like neuroleptics, and it might occur during treatment with selective serotonine reuptake inhibitors. It is possible that non psychiatric drugs that block dopaminergic receptors, like bromopride, might cause patients to develop extrapyramidal symptoms. OBJECTIVES: To describe an unfavorable outcome clinically characterized by akathisia in a depressed patient previously stabilized with fluvoxamine, after using bromopride. METHODS: Case report. RESULTS: Mr J, 47 year-old depressed patient, had been stabilized with fluvoxamine 200 mg a day. He began abruptly with restlessness and an urgency to produce voluntary movements in order to alleviate such discomfort. Four days earlier he began using bromopride 30 mg a day to treat dyspepsia. Withdrawn of bromopride promoted an immediate relieve of the symptoms. CONCLUSION: Bromopride, a dopaminergic blocker, might have triggered akathisia in a patient using fluvoxamine. The pharmacologic mechanisms regarding this outcome are discussed.

Efeito dos antidepressivos ISRS sobre os hormônios tireoidianos / SSRI antidepressant effects on thyroid hormones

O objetivo deste artigo é realizar uma atualização sobre a ação de antidepressivos, com destaque aos inibidores seletivos de recaptação de serotonina (ISRS) na função tireoidiana de pacientes com depressão. Sete ensaios clínicos investigaram o efeito dos ISRS sobre a função tireoidiana. Apesar das diferenças metodológicas, o principal achado foi a tendência à diminuição dos níveis plasmáticos de tiroxina, não necessariamente relacionada com a resposta clínica, e sem efeito sobre a tireotropina na maioria das pesquisas. Os estudos sugerem que os ISRS promovem efeitos na função tireoidiana em alguns pacientes com depressão, especificamente diminuição nos níveis plasmáticos de tiroxina. Porém, observou-se que a relação entre o uso de antidepressivos ISRS e a função tireoidiana não está suficientemente esclarecida. Mesmo nos casos de alteração nos níveis plasmáticos dos hormônios tireoidianos em resposta a ação dos ISRS, esta pode ser uma ação não específica sobre a função tireoidiana.

This article aims at updating antidepressant action, especially using selective serotonin reuptake inhibitors, on thyroid function in depressed patients. Seven clinical trials investigated the status of thyroid hormones after treatment with SSRIs. Despite methodological differences, the main finding indicated a tendency towards decreased serum thyroxine levels, The majority of studies could not find a positive relationship between lower serum thyroxine level and a favorable treatment response. Also, an effect on thyrotropin could not be found. Those study results suggest SSRIs promote effects on thyroid function in some depressed patients, specifically decreased serum thyroxine levels. However, the relation between SSRIs antidepressant use and thyroid function is not clear. Even when there was a change in serum thyroid hormone levels due to SSRI therapy, this could be a non-specific effect on thyroid function.