Decreased serotonin content and reduced agonist-induced aggregation in platelets of patients chronically medicated with SSRI drugs

Treatment of Concurrent Depression and Its Effect on Outcomes After Total Joint Arthroplasty: A Systematic Review of Comparative Studies

PURPOSE

There is a growing body of evidence suggesting that patients with a diagnosis of depression suffer worse outcomes after total joint arthroplasty (TJA) procedures. It is unclear whether depression treatment is a modifiable risk factor that can be targeted to improve suboptimal outcomes. We conducted a systematic review to understand the role that various interventions have on outcomes of TJA in patients with diagnosed depression (PDDs).

METHODS

PubMed, Ovid MEDLINE, Scopus, and EMBASE were searched systematically from inception until November 2022. Studies of PDDs who underwent TJA that compared any intervention/treatment of depression with a control group and reported pain, functional outcomes, depression scores, and/or revision rates after TJA were relevant for this review.

RESULTS

Ten relevant studies were included in the final systematic review, with a total of 33,501 patients included. Two studies reported lower revision rates for patients receiving selective serotonin reuptake inhibitor treatment and psychotherapy. Two studies showed no difference in functional outcomes for patients receiving pharmacologic treatment. One study reported improved functional outcomes for patients receiving cognitive behavioral therapy and another reported improved postoperative functional outcomes for patients receiving alprazolam.

CONCLUSION

Interventions targeted at PDDs may improve short-term pain and functional outcomes, and there may be an association between selective serotonin reuptake inhibitor use and implant survival. The current literature is limited and inconclusive, with important gaps in understanding regarding the optimization and treatment of this modifiable risk factor. Surgeons should consider depression treatment as a method to improve outcomes in this cohort.

The S/S Genotype of the 5-HTTLPR (Serotonin-Transporter-Linked Promoter Region) Variant of the SLC6A4 Gene Decreases the Risk of Pre-Eclampsia

Pre-eclampsia (PE) is a disorder characterized by hypertension in the second trimester of pregnancy that results from abnormal placentation affecting fetal development and maternal health. Previous studies have shown the role of serotonin (5-HT) that leads to poor placental perfusion, where S/S and S/L polymorphisms promote the solute carrier family 6 member 4 (SLC6A4) gene associated with the risk of developing changes in the microvasculature of the placenta. This study looked at the association between the gene variant 5-HTTLPR (serotonin-transporter-linked promoter region) of the SLC6A4 gene and the occurrence of PE. A total of 200 women were included: 100 cases (pregnant with PE) and 100 controls (pregnant without complications). Genotyping of the 5-HTTLPR variant was performed using polymerase chain reaction (PCR). Associations between the presence of the genetic variant of interest and PE and other clinical features were evaluated statistically. The frequencies of S/S, S/L, and L/L genotypes were 32%, 53%, and 15% for the cases and 55%, 25%, and 20% in the control group. Compared to the controls, the genotype frequencies S/S vs. S/L + L/L (recessive model) in the cases group were different (p = 0.002). The S/S genotype decreased the probability of PE (OR = 0.39, 95% IC: 0.22-0.69, p = 0.002) and PE with severity criteria (OR = 0.39, 95% IC: 0.17-0.91, p = 0.045). The 5-HTTLPR gene variant of the SLC6A4 gene modifies the risk of PE development among the studied population.

Serotonin syndrome caused by a CYP2C19-mediated interaction between low-dose escitalopram and clopidogrel: a case report

Background

Serotonin syndrome has been recognized as a serious adverse reaction to antidepressants and is characterized by sudden or severe autonomic nerve dysfunction and neuromuscular symptoms. Without an accurate diagnosis and prompt treatment, serotonin syndrome progresses rapidly and can be life-threatening. It is usually related to the dose of 5-hydroxytryptamine drugs, and the dose is the basis for diagnosis. Therefore, serotonin syndrome induced by low-dose antidepressants rarely occurs, and clinicians are more likely to misdiagnose patients who take low-dose antidepressants with similar symptoms. Here, we present a case study of serotonin syndrome caused by a relatively low dose of escitalopram, which is not common in past references.

Case summary

The patient was a 74-year-old Asian woman with a 42-year history of schizophrenia. After 6 weeks of antidepressant treatment, our patient presented with characteristic myoclonus in the lower limbs and closed eyes with fluttering. Initially, she was misdiagnosed with neuroleptic malignant syndrome (NMS) due to antipsychotic medication and was treated accordingly, even with discontinuation of clozapine. However, her symptoms persisted, and then therapeutic drug monitoring was initiated with the involvement of a clinical pharmacist. Eventually, she was diagnosed with serotonin syndrome due to escitalopram levels reaching the warning level. Subsequently, the patient's treatment was modified, and her clinical outcome was satisfactory without any other serious adverse reactions. Gene detection was also performed, and a cytochrome P450 enzyme (CYP) 2C19-mediated interaction between low-dose escitalopram and clopidogrel seems to be a possible mechanism.

Conclusion

Data on this is extremely scarce, and to the best of our knowledge, serotonin syndrome caused by low-dose antidepressants has not yet been discussed to any great extent in the literature. Our case provides more clinical experience in the treatment of serotonin syndrome.

Baseline platelet serotonin in a multi-site treatment study of depression in veterans administration patients: Distribution and effects of demographic variables and serotonin reuptake inhibitors

BACKGROUND

The objectives of the study were: (1) to examine the overall distribution of baseline platelet serotonin (5-hydroxytryptamine, 5-HT) values in patients seeking treatment for depression and to define subgroups based on the apparent presence or absence of drug exposure; (2) to assess the bioeffect of 5-HT reuptake inhibitors (SRIs) at the platelet 5-HT transporter; and (3) to examine the relationships of demographic variables including population (ancestry), sex, age, and season of sampling to platelet 5-HT concentration.

METHODS

Platelet 5-HT levels were measured in a cross-sectional study of 1433 Veterans Administration (VA) patients participating in a pragmatic multi-site pharmacogenomic treatment study of depression. Patients were characterized medically and demographically using VA health records and self-report.

RESULTS

A clearly bimodal distribution was observed for platelet 5-HT levels with the lower mode associated with patients exposed to SRIs at baseline. Median transporter blockade bioeffects were similar across the various selective 5-HT reuptake inhibitors (SSRIs) and 5-HT/norepinephrine reuptake inhibitors (SNRIs). In a subset of patients apparently not exposed to an SRI, significant effects of population and sex were observed with group mean platelet 5-HT levels being 25 % greater (p < 0.001) in African-American (AA) individuals compared to European-Americans (EAs). The female group mean was 14 % (p < 0.001) greater than male group mean. An effect of age was observed (r = -0.11, p < 0.001) and no effect of season or month of sampling was seen.

CONCLUSIONS

Further research is warranted to understand the bases and clinical implications of the population and sex differences. The apparent similarity in bioeffect at the 5-HT transporter across SSRIs and when comparing SSRIs and SNRIs informs discussions about initiating, dose adjustment and switching of 5-HT reuptake inhibitors.

Could peripheral 5-HT level be used as a biomarker for depression diagnosis and treatment? A narrative minireview

The serotonin hypothesis of depression is still influential, but the relationship between peripheral 5-HT levels and depression is still unknown. This review aimed to verify whether peripheral 5-HT levels could be used as a biomarker for depression diagnosis and treatment. PubMed and EMBASE were searched using terms appropriate to the area of research. Articles from 1957 to 2022 in the following terms were identified: depression, 5-HT, serotonin and peripheral (serum, plasma, blood platelets). 33 studies were included: seven clinical trials about periphery 5-HT levels in depressive patients compared to normal subjects, 15 clinical trials about changes of peripheral 5-HT levels in patients with depression after drug treatment and 11 animal experiments about peripheral 5-HT levels in animal models of depression. Peripheral 5-HT levels presented three different outcomes before and after antidepressant treatments: increased, decreased and no significant change. In conclusion, changes in peripheral 5-HT levels did not show consistent results among these studies. Peripheral 5-HT level could not be used as a biomarker both for depression diagnosis and for antidepressant efficacy evaluation.

Systematic review of studies using platelet serotonin content to assess bioeffect of serotonin reuptake inhibitors at the serotonin transporter

RATIONALE

Assessment of the bioeffect of serotonin reuptake inhibitors (SRIs, including both selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs)) at the serotonin transporter (SERT) in patients and healthy controls can have important theoretical and clinical implications.

OBJECTIVES

Bioeffect at SERT has been assessed by neuroimaging of brain SERT occupancy, through in vitro measurements of platelet serotonin (5-HT) uptake, and by measuring platelet 5-HT content pre- and post-initiation of SRI administration. Studies of platelet 5-HT content were reviewed in order to (1) determine the overall apparent bioeffect of SRIs; (2) compare bioeffect across types of SRIs; (3) compare the three approaches to assessing SRI bioeffect; and (4) determine how the findings might inform clinical practice.

METHODS

We performed a systematic review of the published studies that measured platelet 5-HT content to assess SRI bioeffect at the platelet SERT. Studies using neuroimaging and in vitro platelet 5-HT uptake to assess SRI bioeffect were reviewed for comparison purposes.

RESULTS

Clinical doses of SRIs typically resulted in 70-90% reductions in platelet 5-HT content. The observed bioeffect at the platelet SERT appeared similar among different SSRIs and SNRIs. The bioeffect estimations based on platelet 5-HT content were consistent with those obtained using neuroimaging to assess brain SERT occupancy and those based on the in vitro measurement of platelet 5-HT uptake.

CONCLUSIONS

In general, excellent agreement was seen in the apparent SRI bioeffect (70-90% inhibition) among the platelet 5-HT content studies and across the three bioeffect approaches. Theoretical and practical clinical implications are discussed.

Systematic Review of the Serotonergic System in the Pathophysiology of Severe Dengue: The Theory of Thrombocytopenia and Vascular Extravasation

BACKGROUND

Severe dengue is characterized by thrombocytopenia, hemorrhaging, and/or capillary extravasation and may be linked to a reduced plasma concentration of serotonin (5-hydroxytriptamine, or 5-HT).

OBJECTIVE

The aim of the current contribution was to conduct a systematic bibliographic review of reports on the role of the peripheral serotonergic system in the pathophysiology of severe dengue.

METHODS

A bibliographic review was carried out of in vivo/in vitro models, clinical trials, and case series studies from 2010-2019. The selective criteria were the use of treatments with serotonin reuptake inhibitors and/or agonists/antagonists of 5-HT receptors and their impact on inflammation, coagulation, and endothelium. Moreover, cross-sectional and cohort studies on the relationship between intraplatelet and plasma 5-HT levels in patients with dengue were also included. The risk of bias in the selected reports was examined with domain-based assessment utilizing Cochrane-type criteria. The main results are summarized in Tables and Figures.

RESULTS

Based on descriptions of the effect of serotonergic drugs on 5-HT levels and the findings of clinical trials of dengue treatment, most receptors of the peripheral serotonergic system, and especially 5-HT2A, seem to participate in regulating serum 5-HT during severe dengue. Therefore, the peripheral serotonergic system probably contributes to thrombocytopenia and capillary extravasation.

CONCLUSION

Regarding dengue, 5-HT may be a key parameter for predicting severity, and an understanding of 5-HT-related mechanisms could possibly facilitate the development of new therapies. These proposals require further research due to the limited number of publications on the role of serotonergic receptors at the peripheral level.

Selective serotonin reuptake inhibitors and preeclampsia: A quality assessment and meta-analysis

Serotonin modulates vascular, immune, and neurophysiology and is dysregulated in preeclampsia. Despite biological plausibility that selective serotonin reuptake inhibitors (SSRIs) prevent preeclampsia pathophysiology, observational studies have indicated increased risk and providers may be hesitant. The objective of this meta-analysis and quality assessment was to evaluate the evidence linking SSRI use in pregnancy to preeclampsia/gestational hypertension. PubMed was searched through June 5, 2020 manually and using combinations of terms: "preeclampsia", "serotonin", and "SSRI". This review followed MOOSE guidelines. Inclusion criteria were: 1) Observational cohort or population study, 2) exposure defined as SSRI use during pregnancy, 3) cases defined as preeclampsia or gestational hypertension, and 4) human participants. Studies were selected that addressed the hypothesis that gestational SSRI use modulates preeclampsia and/or gestational hypertension risk. Review Manager Web was used to synthesize study findings. Articles were read and scored (Newcastle-Ottawa Quality Assessment Scale) for quality by two independent reviewers. Publication bias was assessed using a funnel plot and the Egger test. Of 179 screened studies, nine were included. The pooled risk ratio (random effects model) was 1.43 (95 % CI: 1.15-1.78, P < 0.001; range 0.96-4.86). Two studies were rated as moderate quality (both with total score of 6); others were high quality. Heterogeneity was high (I2 = 88 %) and funnel asymmetry was significant (p < 0.00001). Despite evidence for increased preeclampsia risk with SSRIs, shared risk factors and other variables are poorly controlled. Depression treatment should not be withheld due to perceived gestational hypertension risk. Mechanistic evidence for serotonin modulation in preeclampsia demonstrates a need for future research.

Selective Serotonin Reuptake Inhibitors and Associated Bleeding Risks: A Narrative and Clinical Review

Major Depressive Disorder (MDD) is a major cause of disability worldwide and is associated with serious lasting impairment. A leading hypothesis of the pathophysiology of MDD is the monoamine deficiency hypothesis which suggests that depression is caused by depletion of serotonin, norepinephrine, or dopamine in the central nervous system. Serotonin is the most widely studied neurotransmitter in the pathophysiology of depression, with studies showing that reduced central serotonin synthesis leads to depressive symptoms in individuals at risk for depression. Selective Serotonin Reuptake Inhibitors (SSRI) inhibit serotonin reuptake and subsequently increase the amount of serotonin available in synapses. Common side effects of SSRIs include increased suicidality of patients under the age of 25, sexual dysfunction, anxiety, dizziness, weight gain, gastrointestinal distress, and headache. Other side effects include prolonging the QT interval, coagulopathy, and the risk of serotonin syndrome, as well as SSRI discontinuation syndrome. Sites of increased bleeding related to SSRI use have been reported to occur in the upper gastrointestinal tract, as well as intracranially. Based on the current literature, three studies have found that SSRIs are not associated with increased bleeding and/or increased perioperative risk, while others have demonstrated that SSRIs are associated with an increased risk in perioperative use. The inhibition of serotonin reuptake can affect platelet aggregation since platelets also express the serotonin transporter. SSRIs can result in decreased storage of serotonin in platelet dense granules. Increased serotonin can also increase gastric acid secretion, which increases the risk for ulceration. SSRIs in combination with NSAIDs also show a significantly increased risk of upper GI bleeding. Some studies show an increased bleeding risk from 30% to 70% when taking a combination of vitamin K antagonists and SSRIs in hospitalized patients. Related to the high prevalence of conditions that are treated with SSRIs, the bleeding risk associated with this class of medication merits further study.

Selective serotonin reuptake inhibitors increase risk of upper gastrointestinal bleeding when used with NSAIDs: a systemic review and meta-analysis

The use of selective serotonin reuptake inhibitors (SSRIs) can increase the risk of gastrointestinal (GI) bleeding. Similarly, it is well known that the use of NSAIDs predisposes patients to upper GI bleeding. The aim of this study was to explore if the addition of SSRIs in patients already taking NSAIDs significantly increases their risk for upper GI bleeding. An electronic literature search was conducted using the SCOPUS and MEDLINE databases from inception through September 2020. Cohort and case-control trials that reported patients with upper GI bleeding on NSAIDs with SSRIs, compared to controls on NSAIDs only were included. Newcastle-Ottawa checklist was used to ensure inclusion of high-quality studies. Data was extracted by the lead investigator and cross-checked by the second author. Dichotomous data was pooled to obtain an odds ratio (OR) of the risk of upper GI bleeding in patients on NSAIDs with concomitant SSRI use. The primary endpoint of the study was the risk of upper GI bleeding with SSRIs and NSAIDs compared to NSAIDs alone. A total of 366 citations were reviewed, and 21 were selected for full-text evaluation. 1 cohort and 9 case-control studies were eligible. There was an additional increased risk of upper GI bleeding in patients on NSAIDs with concomitant SSRI use (OR 1.75, 95% CI = 1.32-2.33). In patients already on NSAID therapy, the concomitant use of SSRIs can significantly increase the risk of upper of GI bleeding.

Neutrophil to lymphocyte ratio, platelet to lymphocyte ratio, and monocyte to lymphocyte ratio in depression: A meta-analysis

BACKGROUND

The possible associations between depression and neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and monocyte to lymphocyte ratio (MLR) have been evaluated in numerous studies. But the results were still controversial.

METHODS

The WEB OF SCIENCE, PUBMED, EMBASE, and COCHRANE LIBRARY databases were searched for eligible studies. Standardized mean difference (SMD) and 95% confidence interval (CI) were used to assess the differences in NLR, PLR, and MLR levels between depressed patients and controls.

RESULTS

Two thousand five hundred and eighty cases and 2664 controls, 1393 cases and 1370 controls, 744 cases and 765 controls were identified in the meta-analyses for NLR, PLR, and MLR, respectively. The pooled analyses showed that depressed subjects had significantly higher levels of NLR than healthy controls (SMD = 0.33, 95% CI = 0.15-0.15, P < 0.001). Sensitivity analysis and publication bias test confirmed the result. Subgroup analyses suggested that the association between depression and NLR could be affected by country, study design, and antidepressant treatment. While no significant difference of PLR (SMD = 0.13, 95% CI = -0.04-0.31, P = 0.140) and MLR (SMD = 0.02, 95% CI = -0.24-0.28, P = 0.892) values was found between depressed subjects and controls.

LIMITATIONS

High heterogeneity was noted across studies.

CONCLUSIONS

The present meta-analysis supported the hypothesis that depression is associated with inflammation, and NLR can be used as an indicator of depression. Further large-scale studies are warranted, especially those that evaluate PLR or MLR in depression.

Impact of Fluoxetine Treatment and Folic Acid Supplementation on the Mammary Gland Transcriptome During Peak Lactation

Serotonin is a key regulator of mammary gland homeostasis during lactation. Selective serotonin reuptake inhibitors (SSRIs) are commonly used to treat peripartum depression, but also modulates mammary gland serotonin concentrations and signaling in part through DNA methylation. The objective of this study was to determine mouse mammary transcriptome changes in response to the SSRI fluoxetine and how methyl donor supplementation, achieved by folic acid supplementation, affected the transcriptome. Female C57BL/6J mice were fed either breeder diet (containing 4 mg/kg folic acid) or supplemented diet (containing 24 mg/kg folic acid) beginning 2 weeks prior to mating, then on embryonic day 13 mice were injected daily with either saline or 20 mg/kg fluoxetine. Mammary glands were harvested at peak lactation, lactation day 10, for transcriptomic analysis. Fluoxetine but not folic acid altered circulating serotonin and calcium concentrations, and folic acid reduced mammary serotonin concentrations, however only fluoxetine altered genes in the mammary transcriptome. Fluoxetine treatment altered fifty-six genes. Elovl6 was the most significantly altered gene by fluoxetine treatment along with gene pathways involving fatty acid homeostasis, PPARγ, and adipogenesis, which are critical for milk fat synthesis. Enriched pathways in the mammary gland by fluoxetine revealed pathways including calcium signaling, serotonin receptors, milk proteins, and cellular response to cytokine stimulus which are important for lactation. Although folic acid did not impact specific genes, a less stringent pathway analysis revealed more diffuse effects where folic acid enriched pathways involving negative regulation of gene expression as expected, but additionally enriched pathways involving serotonin, glycolysis, and lactalbumin which are critical for lactation. In conclusion, peripartal SSRI use and folic acid supplementation altered critical genes related to milk synthesis and mammary gland function that are important to a successful lactation. However, folic acid supplementation did not reverse changes in the mammary gland transcriptome altered by peripartal SSRI treatment.

Peripartal treatment with low-dose sertraline accelerates mammary gland involution and has minimal effects on maternal and offspring bone

Women mobilize up to 10% of their bone mass during lactation to provide milk calcium. About 8%–13% of mothers use selective serotonin reuptake inhibitors (SSRI) to treat peripartum depression, but SSRIs independently decrease bone mass. Previously, peripartal use of the SSRI fluoxetine reduced maternal bone mass sustained post‐weaning and reduced offspring bone length. To determine whether these effects were fluoxetine‐specific or consistent across SSRI compounds, we examined maternal and offspring bone health using the most prescribed SSRI, sertraline. C57BL/6 mice were given 10 mg/kg/day sertraline, from the beginning of pregnancy through the end of lactation. Simultaneously, we treated nulliparous females on the same days as the primiparous groups, resulting in age‐matched nulliparous groups. Dams were euthanized at lactation day 10 (peak lactation, n = 7 vehicle; n = 9 sertraline), lactation day 21 (weaning, n = 9 vehicle; n = 9 sertraline), or 3m post‐weaning (n = 10 vehicle; n = 10 sertraline) for analysis. Offspring were euthanized at peak lactation or weaning for analysis. We determined that peripartum sertraline treatment decreased maternal circulating calcium concentrations across the treatment period, which was also seen in nulliparous treated females. Sertraline reduced the bone formation marker, procollagen 1 intact N‐terminal propeptide, and tended to reduce maternal BV/TV at 3m post‐weaning but did not impact maternal or offspring bone health otherwise. Similarly, sertraline did not reduce nulliparous female bone mass. However, sertraline reduced immunofluorescence staining of the tight junction protein, zona occludens in the mammary gland, and altered alveoli morphology, suggesting sertraline may accelerate mammary gland involution. These findings indicate that peripartum sertraline treatment may be a safer SSRI for maternal and offspring bone rather than fluoxetine.

Added burden of major depressive disorder on cardiovascular morbidity and mortality among patients with cardiovascular disease and the modifying effects of antidepressants: A national retrospective cohort study

BACKGROUND

To evaluate the likelihood of a future cardiovascular event (i.e., in-hospital mortality or cardiovascular disease [CVD] complications/interventions) among patients with CVD and major depressive disorder (MDD) compared to those without MDD, and the antidepressant use on future cardiovascular events between the two groups.

METHODS

This is a retrospective cohort with propensity score matching with 8941 patients with CVD and MDD, and 8941 non-MDD patients using data from the Longitudinal Health Insurance Database from 1999 to 2013 in Taiwan. The outcome was in-hospital mortality and the incidence of revascularization (i.e., percutaneous transluminal coronary angioplasty [PTCA] and coronary artery bypass graft surgery [CABG]).

RESULTS

Patients with CVD and MDD were more likely to need revascularization (an adjusted hazard ratio [aHR]: 1.26 and 95% CI: 1.12-1.43) than those without MDD, regardless of whether PTCA (aHR: 1.23 and 95% CI: 1.07-1.40) or CABG (aHR: 1.60 and 95% CI: 1.16-2.21) had occurred. Antidepressant use was associated with a tendency of reduced risk of mortality (aHR: 0.92 and 95% CI: 0.84-1.00). Although the magnitude of aHR ranged from 0.92 to 0.95 with revascularization, they did not reach significant levels.

LIMITATIONS

Some covariates could not be controlled because they were not included in the national register dataset, and the causality is limited in an observational study.

CONCLUSIONS

Patients with CVD with MDD are more likely to experience a cardiovascular complication requiring intervention than CVD patients without MDD. Antidepressant use is associated with reduced in-hospital mortality.

Analysis of cytokine levels, T regulatory cells and serotonin content in patients with depression

Alterations in peripheral serotonin concentrations and an imbalanced immune system have been reported in patients with depression. Cytokines and T regulatory (Treg) cells may play an important role in the development of depression. This study investigates the levels of cytokines and Treg cells, as well as the concentration of serotonin (5-HT) in the blood of 89 patients suffering from depression and 89 healthy participants between two acquisitions. We investigated the state of health before (T1) and after (T2) psychological and pharmacological therapy. Both cytokine (IL-6, IL-10, TNF-α, and INF-γ) and 5-HT levels in the blood were measured by enzyme-linked immunosorbent assays. The levels of CD4⁺ CD25⁺ Treg cells were determined by flow cytometric analysis. Patients with depression showed significantly higher serum levels of IL-6 and INF-γ, no altered serum levels of IL-10 and TNF-α, and decreased platelet and serum 5-HT levels compared with healthy participants at the first acquisition. In addition, the symptoms of depression and anxiety, the TNF-α level, and the amount of CD4⁺ CD25⁺ cells in the blood were decreased from the first to the second acquisition. Further, a correlation between IL-6 and platelet 5-HT has been observed in patients. An imbalance of the immune system in patients with depression and an association of the serotonergic system and cytokines were observed. These results indicate that the development of depression might be related to several interacting proteins, including cytokines and 5-HT, and the treatment affects imbalances of these factors.

Ergot alkaloids reduce circulating serotonin in the bovine

Ergot alkaloids can interact with several serotonin (5-hydroxytryptamine [5-HT]) receptors provoking many physiological responses. However, it is unknown whether ergot alkaloid consumption influences 5-HT or its metabolites. Thus, two experiments were performed to evaluate the effect of ergot alkaloid feeding on 5-HT metabolism. In exp. 1, 12 Holstein steers (260 ± 3 kg body weight [BW]) were used in a completely randomized design. The treatments were the dietary concentration of ergovaline: 0, 0.862, and 1.282 mg/kg of diet. The steers were fed ad libitum, kept in light and temperature cycles mimicking the summer, and had blood sampled before and 15 d after receiving the treatments. The consumption of ergot alkaloids provoked a linear decrease (P = 0.004) in serum 5-HT. However, serum 5-hydroxytryptophan and 5-hydroxyindoleacetic acid did not change (P > 0.05) between treatments. In exp. 2, four ruminally cannulated Holstein steers (318 ± 3 kg BW) were used in a 4 × 4 Latin square design to examine the difference between seed sources on 5-HT metabolism. Treatments were: control-tall fescue seeds free of ergovaline, KY 32 seeds (L42-16-2K32); 5Way-endophyte-infected seeds, 5 way (L152-11-1739); KY31-endophyte-infected seeds, KY 31 (M164-16-SOS); and Millennium-endophyte-infected seeds, 3rd Millennium (L108-11-76). The endophyte-infected seed treatments were all adjusted to provide an ergovaline dosage of 15 μg/kg BW. The basal diet provided 1.5-fold the net energy requirement for maintenance. The seed treatments were dosed directly into the rumen before feeding. The experiment lasted 84 d and was divided into four periods. In each period, the steers received seeds for 7 d followed by a 14-d washout. Blood samples were collected on day 0 (baseline) and day 7 for evaluating the treatment response in each period. A 24 h urine collection was performed on day 7. Similar to exp. 1, serum 5-HT decreased (P = 0.008) with the consumption of all endophyte-infected seed treatments. However, there was no difference (P > 0.05) between the infected seeds. The urinary excretion of 5-hydroxyindoleacetic acid in the urine was not affected (P > 0.05) by the presence of ergot alkaloids. In conclusion, the consumption of ergot alkaloids decreases serum 5-HT with no difference between the source of endophyte-infected seeds in the bovine.

A scoping review of the pathophysiology of COVID-19

COVID-19 is a highly heterogeneous and complex medical disorder; indeed, severe COVID-19 is probably amongst the most complex of medical conditions known to medical science. While enormous strides have been made in understanding the molecular pathways involved in patients infected with coronaviruses an overarching and comprehensive understanding of the pathogenesis of COVID-19 is lacking. Such an understanding is essential in the formulation of effective prophylactic and treatment strategies. Based on clinical, proteomic, and genomic studies as well as autopsy data severe COVID-19 disease can be considered to be the connection of three basic pathologic processes, namely a pulmonary macrophage activation syndrome with uncontrolled inflammation, a complement-mediated endothelialitis together with a procoagulant state with a thrombotic microangiopathy. In addition, platelet activation with the release of serotonin and the activation and degranulation of mast cells contributes to the hyper-inflammatory state. Auto-antibodies have been demonstrated in a large number of hospitalized patients which adds to the end-organ damage and pro-thrombotic state. This paper provides a clinical overview of the major pathogenetic mechanism leading to severe COVID-19 disease.

Antidepressants Promote and Prevent Cancers

The review states that antidepressants (ADs) increase brain-derived neurotrophic factor (BDNF) transmission concomitantly in the brain and the blood: ADs increasing BDNF synthesis in specific areas of the central nervous system (CNS) could presumably affect megakaryocyte's production of platelets. ADs increase BDNF levels in the CNS and improve mood. In the blood, ADs increase BDNF release from platelets. The hypothesis presented here is that the release of BDNF from platelets contributes to the ADs effects on neurogenesis and on tumor growth in the cancer disease. Oncological studies indicate that chemicals ADs exert an aggravating effect on the cancer disease, possibly by promoting proplatelets formation and enhancing BDNF release from platelets in the tumor.

Demonstration of an action pathway in mouse platelets leading to prolongation of bleeding time by fluoxetine

Fluoxetine is one of SSRIs commonly used as first-line antidepressants. It also induces adverse effects, including bleeding events. This study clarified the bleeding effect of fluoxetine and explored the action cascade of this drug leading to a longer bleeding time. A total of 48 male adult mice were evenly distributed into four groups and given fluoxetine in saline at 0, 4, 8, or 16 mg/kg, for 14 days. On day 15, tail bleeding time of 6 mice/group was measured, and their blood samples were collected for analyses of relevant platelet functions. The remained mice were allowed to survive for another 14 days without fluoxetine, and subjected to the same analyses on day 29. A significant effect of fluoxetine was reveled on bleeding time (F _(3,20) = 16.842, P < 0.01) and intraplatelet serotonin (F _(3,20) = 90.967, P < 0.01). Moreover, fluoxetine effectively inhibited platelet aggregation (F_{(3, 20)} = 30.247, P < 0.01), decreased amount of GPIbα (F_{(3, 20)} = 23.855, P < 0.01), suppressed GPIIb/IIIa activation (F_{(3, 20)} = 89.441, P < 0.01), and lowered P-selectin (F_{(3, 20)} = 7.960, P < 0.01) on platelet surface. Negative correlations existed between bleeding time and the aforementioned four indices, whereas correlations between intraplatelet serotonin and the same indices were positive. All changes returned to same levels as Control group after fluoxetine withdrawal. These data suggest an action pathway of fluoxetine starting at binding to serotonin transporter, followed by decreased intraplatelet serotonin, increased GPIbα shedding, suppressed GPIIb/IIIa activation, and inhibited α-granule release, and concluding with prolonged bleeding time in mice.

Novel antiplatelet targets in the treatment of acute coronary syndromes

Acute coronary syndromes (ACS) are a global cause of mortality and morbidity that affect millions of lives worldwide. Following atherosclerotic plaque rupture, platelet activation and aggregation are the two major elements that initiate thrombus formation inside a coronary artery, which can obstruct blood flow and cause myocardial ischemia; ergo, antiplatelet therapy forms a major part of the treatment strategy for ACS. Patients with ACS routinely receive dual antiplatelet therapy (DAPT), which consists of aspirin and a platelet P2Y₁₂ inhibitor to both treat and prevent atherothrombosis. Use of platelet glycoprotein (GP) IIb/IIIa inhibitors is now limited due to the risk of severe bleeding and thrombocytopenia. Thus, administration of GPIIb/IIIa inhibitors is generally restricted to bail out thrombotic events associated with PCI. Furthermore, current antiplatelet medications mainly rely on thromboxane A₂ and P2Y₁₂ inhibition, which have broad-acting effects on platelets and are known to cause bleeding, which especially limits the long-term use of these agents. In addition, not all ACS patients treated with current antiplatelet treatments are protected from recurrence of arterial thrombosis, since many platelet mechanisms and activation pathways remain uninhibited by current antiplatelet therapy. Pharmacological antagonism of novel targets involved in platelet function could shape future antiplatelet therapies that could ultimately lead to more effective or safer therapeutic approaches. In this article, we focus on inhibitors of promising targets that have not yet been introduced into clinical practice, including inhibitors of GPVI, protease-activated receptor (PAR)-4, GPIb, 5-hydroxytryptamine receptor subtype 2A (5-HT_2A), protein disulfide isomerase, P-selectin and phosphoinositide 3-kinase β.

The association between serum serotonin levels and overactive bladder: results from a community-based cross-sectional study in Japan

PURPOSE

To investigate the association between serum serotonin (5-HT) levels and overactive bladder (OAB) in a community-dwelling population.

METHODS

This cross-sectional study analyzed 1024 subjects who participated in the Iwaki Health Promotion Project in 2015 in Hirosaki, Japan. OAB was assessed using the Overactive Bladder Symptom Score (OABSS). OAB was defined as an occurrence of urinary urgency at least once a week and an OABSS of ≥ 3. We assessed serum 5-HT levels, laboratory data, and comorbidities of each participants. Participants' mental health status was evaluated using the Center for Epidemiologic Studies Depression (CES-D) scale. The association of serum 5-HT levels and OAB was analyzed by multivariable logistic regression analysis.

RESULTS

This study included 394 men and 630 women. Of those, 118 (44 male and 74 female) were OAB sufferers. There were significant group differences in age, history of cardiovascular disease, chronic kidney disease, hypertension, diabetes mellitus, and CES-D score. Participants' serum 5-HT levels in the OAB group were significantly lower than those in the non-OAB group (100 vs. 127 ng/mL, P < 0.001). Multivariable analysis showed that age (odds ratio [OR]; 1.06, 95% confidence interval [CI]; 1.04-1.08, P < 0.001) and log serum 5-HT level (OR; 0.25, 95% CI; 0.10-0.68, P = 0.006) were independently associated with OAB.

CONCLUSIONS

Lower serum 5-HT levels could independently be associated with the presence of OAB. Further study is necessary to elucidate a possible causal relationship between serum 5-HT levels and OAB.

Perioperative Selective Serotonin Reuptake Inhibitor Use Is Associated With an Increased Risk of Transfusion in Total Hip and Knee Arthroplasty

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) have been shown in both orthopedic and general surgery literature to be associated with an increased risk of blood loss, and this is thought to occur via diminished platelet serotonin reuptake and subsequent decline in platelet aggregation potential. In this study, we aim at quantifying the effect of treatment with SSRIs on blood loss and transfusion rates following total hip (THA) or total knee arthroplasty (TKA).

METHODS

THA (4485) and TKA (5584) cases from January 2013 to December 2017 at the investigating institution were queried and analyzed separately from an institutional database. Patients were stratified by utilization of an SSRI at the time of surgery. Patient demographics, baseline coagulopathy, preoperative and postoperative hemoglobin, transfusion, and length of stay were obtained to compare the 2 cohorts.

RESULTS

The transfusion rate for SSRI users was 3.9% in the TKA group and 8.5% in the THA group. After controlling for age, gender, body mass index, presence of coagulopathy, procedure (THA vs TKA), and SSRI status, SSRI utilization was significantly associated with increased blood loss (P < .004), and logistic regression controlling for the same variables showed SSRI utilization to be predictive of transfusion (odds ratio, 1.476; P < .001).

CONCLUSION

SSRI utilization was associated with increased perioperative blood loss and predictive of transfusion risk, particularly with THA. This represents an important factor that may be modified in the setting of total joint arthroplasty but further work will be necessary to study potential alternative medications for depression in the perioperative phase.

Selective Serotonin Reuptake Inhibitor Use and Hip Fracture Risk Among Patients on Hemodialysis

RATIONALE & OBJECTIVE

Use of selective serotonin reuptake inhibitors (SSRIs) has been associated with hip fracture risk in the general population. This study examined this relationship among patients with kidney failure treated by hemodialysis, a unique high-risk subpopulation, within which the impact of SSRIs on hip fracture risk remains unexplored.

STUDY DESIGN

Case-control study.

SETTINGS & PARTICIPANTS

Eligible cases of hip fracture among maintenance hemodialysis patients between January 1, 2009, and September 30, 2015, were identified using the US Renal Data System. Each case was matched on index date with 10 eligible controls. To be eligible, study participants needed to have more than 1 year of Medicare Parts A and B coverage and more than 3 years of Part D coverage. For a separate examination of new short-term SSRI exposure, we selected cases and controls with more than 18 months of Part D coverage and no prior antidepressant use for 1 year.

EXPOSURE

During the 3-year Part D coverage period, use of SSRIs characterized as any (≥1 prescription filled), low, moderate, and high use (<20%, 20%-<80%, and≥80% of days covered by filled prescriptions, respectively).

OUTCOME

We selected cases using International Classification of Diseases, Ninth Revision codes 820.xx and 821.xx. In addition to 1 of these codes tied to a hospitalization, we required a corresponding surgical procedural code within 7 days of diagnosis.

ANALYTIC APPROACH

Conditional logistic regression to estimate unadjusted and multivariable-adjusted ORs and 95% CIs.

RESULTS

We identified 4,912 cases and 49,120 controls. SSRI use was associated with increased hip fracture risk (adjusted OR, 1.25; 95% CI, 1.17-1.35). Risk for fracture was estimated for any, low, moderate, and high SSRI use: adjusted conditional ORs were 1.25 (95% CI, 1.17-1.35), 1.20 (95% CI, 1.08-1.32), 1.31 (95% CI, 1.18-1.43), and 1.26 (95% CI, 1.12-1.41), respectively. The association between hip fracture events and SSRI use was also seen in the examination of new short-term use (adjusted OR, 1.43; 95% CI, 1.23-1.67).

LIMITATIONS

Biomarkers of mineral bone disorder were not captured and accounted for in this analysis.

CONCLUSIONS

We demonstrated an association between increased hip fracture risk and both long- and new short-term SSRI use. The stronger association with new short-term use may suggest an acute mechanism potentially related to falls.

Thromboelastography with Platelet Studies (TEG® with PlateletMapping®) After Rattlesnake Envenomation in the Southwestern United States Demonstrates Inhibition of ADP-Induced Platelet Activation As Well As Clot Lysis

INTRODUCTION

Hematologic effects of North American rattlesnake envenomation can include fibrinogenolysis and thrombocytopenia, depending on species, geography, and other variables. During treatment, these effects are routinely monitored through assessment of fibrinogen concentrations and platelet counts. However, these tests provide no information about fibrinolysis or platelet dysfunction, both of which can also occur with venom from some species.

METHODS

This was a retrospective chart review of patients admitted to a quaternary care academic hospital (Banner - University Medical Center Phoenix) in the southwestern United States for treatment of rattlesnake envenomation, over an approximately 1-year period from March 2017 through April 2018. Patients who had thromboelastography with platelet studies (TEG® with PlateletMapping®) during their care were included.

RESULTS

Twelve patients were identified for this study. Four patients exhibited inhibition of ADP-induced platelet activation: one had normal fibrinogen and platelet count, two had concurrent hypofibrinogenemia, and one had concurrent thrombocytopenia. Crotalidae polyvalent immune Fab (ovine) reversed platelet inhibition in the single patient for whom serial thromboelastographs were available. Fibrinolysis was present in seven patients and resolved in the two patients with serial thromboelastographs.

CONCLUSIONS

Inhibition of ADP-induced platelet aggregation and fibrinolysis occurred independent of hypofibrinogenemia and thrombocytopenia, indicating fibrinogen concentration (or protime) and platelet count monitoring alone is insufficient to assess the extent of hematologic toxicity in rattlesnake envenomation. Crotalidae polyvalent immune Fab (ovine) reversed platelet inhibition in one case, suggesting platelet inhibition could also be used in treatment decisions. Fibrinolysis could also be reversed, although the timing to antivenom administration was less clear.

Acquired platelet function disorders

The possibility of an acquired platelet function disorder should be considered in patients who present with recent onset muco-cutaneous bleeding. Despite the availability of newer and faster platelet function assays, light transmission aggregometry (LTA) remains the preferred diagnostic test. This review examines and discusses the causes of acquired platelet dysfunction; most commonly drugs, dietary factors, medical disorders and procedures. In addition to well-known antiplatelet therapies, clinicians should be alert for newer drugs which can affect platelets, such as ibrutinib. There is little clinical trial evidence to guide the management of acquired platelet function defects, but we summarise commonly employed strategies, which include addressing the underlying cause, antifibrinolytic agents, desmopressin infusions, and in selected patients, platelet transfusions.

Pharmacological Studies Pertaining to Smooth Muscle Relaxant, Platelet Aggregation Inhibitory and Hypotensive Effects of Ailanthus altissima

OBJECTIVE

This in vitro and in vivo study was conducted to rationalize some of traditional medicinal uses of Ailanthus altissima in gastrointestinal, respiratory, and cardiovascular systems.

MATERIALS

Crude extract of Ailanthus altissima (Aa.Cr) and its fractions were prepared and utilized in in vitro and in vivo studies. For in vitro studies, Aa.Cr was investigated on isolated rabbit jejunum, isolated tracheal strip, and isolated aorta of rat suspended in tissue organ bath. Platelet rich and platelet poor plasma were used to study platelet aggregation inhibitory activity. In vivo antidiarrheal effect of Aa.Cr was investigated on balb/c mice pretreated with castor oil to induce diarrhea and SD rats were used to study hypotensive activity.

RESULTS

Concentration dependent spasmolytic effects of Aa.Cr and its DCM fraction (Aa.DCM) were observed on spontaneous and spasmogen induced contractions in jejunum isolated from rabbit, but effect against high potassium (high-K+) induced contractions was more potent. Moreover Aa.Cr showed parallel shifting of calcium response curve to the right side. While its aqueous fraction (Aa.aq) caused spasmogenesis of isolated rabbit jejunum, this effect was blocked partially with prior administration of atropine (1μM). Concentration dependent protection against castor oil induced diarrhea was also observed. Relaxant effect was observed by the application of Aa.Cr and Aa.DCM against high-K+ and carbachol (CCh) induced contractions in tracheal strips isolated from SD rats, while Aa.Aq caused partial relaxation of high-K+ induced contractions, but no effect was observed against CCh induced contractions. Relaxation of rat aorta by the application of Aa.Cr and its fractions was also observed. Inhibition of force of contraction in rabbit atrium was also observed. Inhibition of platelet aggregation was observed against epinephrine and ADP induced aggregation.

CONCLUSION

Keeping in view the observed results, it is concluded that smooth muscle relaxant, platelet aggregation inhibitory and hypotensive effect may be due to the blockage of calcium channels.

Platelet Serotonin Levels Are Associated with Plasma Soluble Leptin Receptor Concentrations in Normoglycemic Women

Most peripheral serotonin (5-hydroxytryptamine (5HT)) is synthetized in the gut with platelets being its main circulating reservoir. 5HT is acting as a hormone in key organs to regulate glucose and lipid metabolism. However, the relation between platelet 5HT levels and traits related to glucose homeostasis and lipid metabolism in humans remains poorly explored. The objectives of this study were (a) to assess the association between platelet 5HT levels and plasma concentration of nonesterified fatty acids (NEFAs) and some adipokines including leptin and its soluble leptin receptor (sOb-R), (b) to assess the association between platelet 5HT levels and anthropometric traits and indexes of insulin secretion/sensitivity derived from oral glucose tolerance test (OGTT), and (c) to evaluate changes in platelet 5HT levels in response to OGTT. In a cross-sectional study, 59 normoglycemic women underwent a standard 2-hour OGTT. Plasma leptin, sOb-R, total and high molecular weight adiponectin, TNFα, and MCP1 were determined by immunoassays. Platelet 5HT levels and NEFAs were measured before and after OGTT. The free leptin index was calculated from leptin and sOb-R measurements. Insulin sensitivity indexes derived from OGTT (HOMA-S and Matsuda ISICOMP) and plasma NEFAs (Adipose-IR, Revised QUICKI) were also calculated. Our data show that among metabolic traits, platelet 5HT levels were associated with plasma sOb-R (r = 0.39, p = 0.003, corrected p = 0.018). Platelet 5HT levels were reduced in response to OGTT (779 ± 237 vs.731 ± 217 ng/10⁹ platelets, p = 0.005). In conclusion, platelet 5HT levels are positively associated with plasma sOb-R concentrations and reduced in response to glucose intake possibly indicating a role of peripheral 5HT in leptin-mediated appetite regulation.

Micromolar concentrations of citalopram or escitalopram inhibit glycoprotein VI-mediated and integrin αIIbβ3-mediated signaling in human platelets

Collagen and convulxin induce platelet aggregation through glycoprotein VI (GPVI)-FcRγ-Syk signaling pathway. In addition, fibrinogen induces platelet activation through integrin αIIbβ3-FcγRIIa-Syk signaling pathway. We previously reported that high concentrations of selective serotonin reuptake inhibitors (SSRI) reduce platelet aggregation induced by collagen. We further investigated the effects of SSRI on GPVI- and αIIbβ3-mediated signaling pathway. Citalopram and escitalopram, two relatively pure SSRI, were used in this study. Both citalopram and escitalopram concentration-dependently inhibited convulxin-induced platelet aggregation, serotonin (5-HT) release and the activation of αIIbβ3. 5-HT concentration in washed platelets was unchanged after short-term treatment with citalopram. The additional 5-HT failed to fully rescue the inhibitory effect of citalopram on convulxin-induced aggregation. Convulxin-induced phosphorylation of Syk, LAT, and Akt was inhibited by citalopram and escitalopram. Citalopram inhibited the interaction between FcRγ and Syk, whereas the phosphorylation of FcRγ in response to convulxin remained unaltered. Further, citalopram inhibited the increase of the interaction between serotonin transporter and Syk induced by convulxin. In the presence of Mn²⁺, escitalopram inhibited the formation of lamellipodia on immobilized fibrinogen. Escitalopram did not influence the binding of fibrinogen to platelets. It inhibited the phosphorylation of Syk and PAK triggered by the adhesion on fibrinogen. Our data demonstrate that micromolar concentrations of citalopram and escitalopram inhibit GPVI- and αIIbβ3-mediated platelet functions. The mechanism of the inhibitory effect of citalopram or escitalopram is not the influence on the activation of GPVI or the interaction between fibrinogen and αIIbβ3, but the interaction between Syk and its upstream molecules.

Variables affecting the potential efficacy of PRP in providing chronic pain relief

Although chronic pain affects about 1% of the US population, it remains largely resistant to treatment. Despite great variability in pain outcomes, the application of autologous platelet-rich plasma (PRP) has become increasingly popular in attempts to reduce chronic pain. The variability in PRP efficacy raises the question of whether PRP actually has an analgesic capacity, and if so, can that capacity be made consistent and maximized. The best explanation for the variability in PRP analgesic efficacy is the failure during PRP preparation and application to take into account variables that can increase or eliminate its analgesic capabilities. This suggests that if the variables are reduced and controlled, a PRP preparation and application protocol can be developed leading to PRP inducing reliable, complete, and long-term pain relief. The goal of this study was to examine some of the variables that influence platelets and see how they might be controlled to increase the analgesic potential of PRP. Among the variables examined are the physiological status of the patient, methods used to prepare PRP, and methods of PRP application. The goal of modifying these variables is to minimize platelet serotonin content, maximize platelet content of factors that reduce inflammation and pain, while maintaining their bioactivity, maximize platelet capacity to aggregate at injury sites, induce rapid and simultaneous release of their contents, and optimize PRP application protocols. It is concluded that controlling some or many of these variables will lead to PRP that induces reliable, maximum, and long-term relief of chronic pain.

Platelet serotonin and serotonin transporter as peripheral surrogates in depression and anxiety patients

Previous studies suggested that serotonergic neurons and platelets share similarities in serotonin (5-HT) uptake by serotonin transporter (SERT), storage, metabolism and release mechanisms, indicating that platelets may be used as a reliable peripheral surrogate to measure central SERT activity in neuropsychiatric research. In this study, platelet 5-HT content and 5-HT uptake capacity of SERT in depression and anxiety patients were measured by ELISA and flow cytometry with IDT307 at baseline and after serotonin reuptake inhibitors (SSRIs) treatment for 4 weeks. Healthy persons matched with age and gender were used as reference. The clinical presentations of the patients were assessed with Hamilton Depression (HAMD) and Anxiety Rating Scales (HAMA) at the same time points. Compared to healthy subjects, anxiety and depression patients showed higher levels of platelet 5-HT and IDT307 fluorescence intensity, but the values were comparable between the patient groups. SSRIs administration for 4 weeks significantly decreased scores of HAMD (29 vs 14) and HAMA (22 vs 14) in depression and anxiety patients, respectively; while it decreased platelet 5-HT content, but did not change the IDT307 fluorescence intensity of platelets. After incubation with fluoxetine in vitro, the IDT307 fluorescence intensity of isolated platelets from both healthy subjects and patients decreased in a dose-dependent manner. These results provide further evidence supporting the employment of platelet 5-HT content and SERT as peripheral surrogates in depression and anxiety patients, and are of help in understanding the several weeks' delay from the initiation of antidepressant medication to their full therapeutic effects in the patients.

High Serum Serotonin Predicts Increased Risk for Hip Fracture and Nonvertebral Osteoporotic Fractures: The MrOS Sweden Study

Because several studies have implicated serotonin as a regulator of bone mass, we here explore its potential association on fracture risk and falls, as on bone mineral density (BMD) and muscle strength, in humans. Serum levels of serotonin were analyzed in 950 men (aged 69 to 81 years), participating in the Gothenburg part of the population-based study MrOS Sweden. Men taking selective serotonin reuptake inhibitors (SSRIs) had a mean value of 31.2 μg/L compared with 159.4 μg/L in those not taking SSRIs. SSRI users were excluded from further analysis. During 10-year follow-up, 224 men exhibited fractures, including 97 nonvertebral osteoporotic fractures (57 hip fractures), and 86 vertebral fractures. Serotonin was associated with hip fracture in linear analysis (hazard ratio [HR] = 1.27, 95% confidence interval [CI] 1.03-1.58) and to all fractures in a nonlinear manner, when quintiles of serotonin was included in quadratic terms (HR = 1.12, 95% CI 1.04-1.21). Men in serotonin quintile 5 had, in multivariable analysis, a HR of 2.30 (95% CI 1.31-4.02) for hip fracture and 1.82 (95% CI 1.17-2.85) for nonvertebral fractures compared with men in quintiles 1 to 4. Men in quintile 1 had, in multivariable analysis, a HR of 1.76 (95% CI 1.03-2.99) for nonvertebral fractures compared with men in quintiles 2 to 4. No association was found with vertebral fractures. Individuals in serotonin quintile 1 had higher prevalence of falls compared with quintiles 2 to 5 (odds ratio = 1.90, 95% CI 1.26-2.87). Serotonin was positively associated with hand-grip strength (r = 0.08, p = 0.02) and inversely with hip BMD (r = -0.10, p = 0.003). To assess the association between SSRIs and falls and fractures, the total MrOS Sweden cohort was examined (n = 3014). SSRI users (n = 90) had increased prevalence of falls (16% versus 33%, p = 0.0001) and increased rate of incident fractures (28.0 versus 44.7 per 1000 person-years, p = 0.018). We present novel data showing that high levels of serotonin predict an increased risk for hip fracture and nonvertebral osteoporotic fractures. © 2018 American Society for Bone and Mineral Research.

Monitoring for antidepressant-associated adverse events in the treatment of patients with major depressive disorder: An international consensus statement

OBJECTIVES

These recommendations were designed to ensure safety for patients with major depressive disorder (MDD) and to aid monitoring and management of adverse effects during treatment with approved antidepressant medications. The recommendations aim to inform prescribers about both the risks associated with these treatments and approaches for mitigating such risks.

METHODS

Expert contributors were sought internationally by contacting representatives of key stakeholder professional societies in the treatment of MDD (ASBDD, CANMAT, WFSBP and ISAD). The manuscript was drafted through iterative editing to ensure consensus.

RESULTS

Adequate risk assessment prior to commencing pharmacotherapy, and safety monitoring during pharmacotherapy are essential to mitigate adverse events, optimise the benefits of treatment, and detect and assess adverse events when they occur. Risk factors for pharmacotherapy vary with individual patient characteristics and medication regimens. Risk factors for each patient need to be carefully assessed prior to initiating pharmacotherapy, and appropriate individualised treatment choices need to be selected. Some antidepressants are associated with specific safety concerns which were addressed.

CONCLUSIONS

Risks of adverse outcomes with antidepressant treatment can be managed through appropriate assessment and monitoring to improve the risk benefit ratio and improve clinical outcomes.

SSRI-reduced platelet reactivity in non-responding patients with life-long Recurrent Depressive Disorder: Detection and involved mechanisms

INTRODUCTION

Adverse effects with bleeding disorders are often associated with the administration of SSRI in depression, although the exact mechanisms remain contradicting. This study is aimed at detecting and exploring the mechanisms of SSRI-induced changes in platelet reactivity in non-responding patients with Recurrent Depressive Disorder (RDD) and life-long exposure to antidepressants.

MATERIALS AND METHODS

Thirty-one patients and thirty-one healthy controls were included in the study. A comprehensive approach which includes evaluation of peripheral markers and microscopic analyses of platelet morphology changes has been used.

RESULTS

RDD SSRI patients have shown blunted aggregatory responses towards collagen and epinephrine. Evident differences in the microscopic evaluation of platelet morphology were observed between the groups, with inherent absence of micro-aggregates and platelet shape changes within the patients; after quantification, the sensitivity and specificity of this method were assessed as high. The abnormalities were found in association with lower platelet serotonin content and high fluctuations of free plasma serotonin levels. Changes in the levels of CRP, fibrinogen and nitric oxide were not observed. Macroplatelets were also detected within RDD SSRI patients via increased MPV, PDW and P-LCR, which were associated with discoid shape and without procoagulant activity.

CONCLUSIONS

The microscopic evaluation might be useful as a simple method for detection of SSRI-reduced platelet function for research purposes or systematic correlations with other biochemical parameters. The mechanisms involved in SSRI-reduced platelet function in non-responding RDD patients are complex, including combined effects of lower platelet serotonin content, high fluctuations in plasma serotonin concentration and abnormal α-AR function.

Citalopram inhibits platelet function independently of SERT-mediated 5-HT transport

Citalopram prevents serotonin (5-HT) uptake into platelets by blocking the serotonin reuptake transporter (SERT). Although some clinical data suggest that selective serotonin reuptake inhibitors (SSRIs) may affect haemostasis and thrombosis, these poorly-characterised effects are not well understood mechanistically and useful in vitro data is limited. We sought to determine whether the inhibitory effects of citalopram on platelets are mediated via its pharmacological inhibition of 5-HT transport. We quantified the inhibitory potency of (RS)-, (R)- and (S)-citalopram on platelet function. If SERT blockade is the primary mechanism for citalopram-mediated platelet inhibition, these potencies should show quantitative congruence with inhibition of 5-HT uptake. Our data show that citalopram inhibits platelet aggregation, adhesion and thromboxane production with no difference in potency between (R)- and (S)-isomers. By contrast, citalopram had a eudysmic ratio of approximately 17 (S > R) for SERT blockade. Furthermore, nanomolar concentrations of citalopram inhibited 5-HT uptake into platelets but had no effect on other platelet functions, which were inhibited by micromolar concentrations. Our data indicate that citalopram-induced inhibition of platelets in vitro is not mediated by blockade of 5-HT transport. This raises a new question for future investigation: by what mechanism(s) does citalopram inhibit platelets?

Platelet haemostatic function in psychiatric disorders: Effects of antidepressants and antipsychotic drugs

Objectives Platelets, the smallest anucleated blood cells, play an essential role in the first step of complex haemostatic process. This review presents the haemostatic function of blood platelets related to their activation in psychiatric disorders (schizophrenia, depression), the role of antipsychotic and antidepressant medication, and introduces the mechanisms by which activated platelets may be involved in the pathophysiology of these disorders. Methods Platelets are interesting and easily accessible blood cells to study biochemical pathways related to schizophrenia and other psychiatric disorders, and their complex activation process might be useful as a diagnostic peripheral marker for studying psychiatric disorders and haemostatic complications. Results The excessive activation of platelets observed in patients with depression and schizophrenia is involved in cardiovascular diseases, stroke and increased risk of thrombotic complications that may be major causes of morbidity and mortality of patients. The use of antidepressants or antipsychotic drugs in depression and schizophrenia treatment is often associated with haematological side effects such as bleeding, venous thromboembolism and impaired platelet function. Conclusions Understanding the role of platelet activation in psychiatric disorders such as schizophrenia or depression and medication may improve therapies in the future.

Depression in Cardiovascular Patients in Middle Eastern Populations: A Literature Review

Cardiovascular disease (CVD) is increasing in Middle Eastern countries. Depression is associated with increased morbidity and mortality rates among cardiovascular (CV) patients. Early detection of and intervention for depression among CV patients can reduce morbidity and mortality and save health care costs. Public information on mental health care needs of Arab CV patients living in Middle East regions is scattered and limited. This literature review surveyed and summarized research studies to learn what is known about the relationship between depression and CVD in Middle Eastern populations. The information will raise awareness among health care professionals and policy makers regarding the clinical significance of depression in Arab CV patients. It might contribute to development of culturally appropriate and effective mental health care services. Multiple databases were searched and 60 articles were assessed, including studies that investigated depression in Arab CV patient populations, physiological mechanisms of depression-CVD comorbidity, and intervention strategies that affect CV risk in depressed Arab patients. We discuss the extent to which this issue has been explored in Arab populations living in Middle East regions and Arab populations living abroad. We recommend that more comprehensive and in-depth research studies be conducted with Arab cardiac patients to enable implementation of culturally appropriate and effective mental health care interventions.

Selective Serotonin Reuptake Inhibitors and Operative Bleeding Risk: A Review of the Literature

OBJECTIVE

This study aimed to review the data on the effect of selective serotonin reuptake inhibitors (SSRIs) on bleeding during or after operative procedures and to offer guidelines for clinical management.

DATA SOURCES

Search of PubMed and MEDLINE for all articles in English from 1990-2016 with key words depression, antidepressants, bleeding, platelets, and operation.

STUDY SELECTION

Studies were included if they reported information on bleeding complications during operative or childbirth procedures in patients taking antidepressants.

DATA EXTRACTION

Because of the limited number and heterogeneity of studies with respect to the range of operative procedures and definition of bleeding complications, a qualitative approach was taken to summarize results rather than abstracting and aggregating data.

RESULTS

The weight of the evidence is that SSRI use increases the risk of bleeding complications during and immediately after surgery. However, given the limited data, we cannot estimate the risk for a given patient having a given procedure.

CONCLUSIONS

Clinicians must consider the risk-to-benefit ratio of discontinuing an SSRI before an elective operative procedure. Discontinuing SSRI medications may result in discontinuation syndrome, symptom recrudescence, or relapse of depression, whereas continuing an SSRI during surgery exposes patients to significant bleeding risks. Antidepressant prescribers must be cognizant of and take responsibility for discussing this potential problem and considering different options. This issue must also be the responsibility of the doctor performing the procedure, but, frequently, it will be the prescribing physician who alerts the surgeon to the potential bleeding risk associated with SSRIs.

Use of Selective Serotonin Reuptake Inhibitors and Risks of Stroke in Patients with Obsessive Compulsive Disorder: A Population-Based Study

Background

Previous research has suggested a link between antidepressants use and the development of cerebrovascular events, but there has never been any study investigating the risk of stroke in obsessive-compulsive disorder (OCD) patients treated with a selective serotonin reuptake inhibitor (SSRI).

Methods

A retrospective observational cohort study was conducted using data from the National Health Insurance Database of Taiwan between the year of 2001 and 2009. A total of 527 OCD patients with 412 subjects in the SSRI use group and 115 in the non SSRI use group were included. Multivariable Cox proportional-hazards models were used to explore the associations between SSRI use and the occurrence of stroke, controlling for age, gender, concomitant medications, and comorbid medical illnesses.

Results

A total of nineteen OCD patients were diagnosed with new onset of stroke during the follow-up period including six cases in the SSRI group and thirteen in the non SSRI use group. SSRI use was demonstrated to be associated with a decreased risk of stroke (hazard ratio [HR] = 0.30; 95% confidence interval [CI] = 0.10–0.86, P = 0.02). The increase in age-related risk of strokes was 2.55 per decade (HR = 2.55; 95% CI = 1.74–3.75, P<0.001). Alternatively, sex, concomitant use of aspirin and non-steroidal anti-inflammatory drugs, and comorbidities with angina pectoris, diabetes mellitus, hypertension, and hyperlipidemia were not found to be associated with an increased risk for stroke in OCD patients.

Conclusions

Our study showed that SSRI use was associated with decreased risk of stroke in OCD patients. Further investigation into the possible biological mechanisms underlying the relationship between stroke and SSRI use in OCD patients is warranted.

Loss of Serotonin Transporter Function Alters ADP-mediated Glycoprotein αIIbβ3 Activation through Dysregulation of the 5-HT2A Receptor

Reduced platelet aggregation and a mild bleeding phenotype have been observed in patients chronically taking selective serotonin reuptake inhibitors (SSRIs). However, it remains unclear how SSRIs, which inhibit the plasma membrane serotonin transporter (SERT), modulate hemostasis. Here, we examine how sustained inhibition of SERT activity alters serotonergic signaling and influences platelet activation and hemostasis. Pharmaceutical blockade (citalopram dosing) or genetic ablation (SERT(-/-)) of SERT function in vivo led to reduced serotonin (5-hydroxytryptamine (5-HT)) blood levels that paralleled a mild bleeding phenotype in mice. Transfusion of wild-type platelets to SERT(-/-) mice normalized bleeding times to wild-type levels, suggesting that loss of SERTs causes a deficiency in platelet activation. Although SERT(-/-) platelets displayed no difference in P-selectin or αIIbβ3 activation upon stimulation with thrombin, ADP-mediated αIIbβ3 activation is reduced in SERT(-/-) platelets. Additionally, synergistic potentiation of αIIbβ3 activation by ADP and 5-HT is lost in SERT(-/-) platelets. Acute treatment of wild-type platelets with 5-HT2A receptor (5-HT2AR) antagonists or SSRIs revealed that functional 5-HT2ARs, not SERTs, are necessary for the synergistic activation of αIIbβ3 by dual 5-HT/ADP stimulation. Pharmacological studies using radiolabeled guanosine 5'-3-O-([(35)S]thio)triphosphate and [(3)H]ketanserin revealed that platelets isolated from SERT(-/-) or citalopram-treated mice have reduced activation of G-proteins coupled to 5-HT2ARs and receptor surface expression. Taken together, these data demonstrate that sustained SERT loss of function reduces 5-HT2AR surface expression that is critical for the synergistic activation of αIIbβ3 by 5-HT and ADP. These results highlight an antiplatelet strategy centered on blocking or desensitizing 5-HT2AR to attenuate ADP-mediated αIIbβ3 activation.

Decreased platelet 5-hydroxytryptamin (5-HT) levels: a response to antidepressants

BACKGROUND

Platelet 5-hydroxytryptamin (serotonin, 5-HT) has been examined for its use as a peripheral biomarker for depression or other mental disorders; however, it remains unclear whether blood 5-HT levels can reflect the brain's levels of serotonin.

METHODS

Platelet 5-HT levels in 45 drug-naïve, 32 citalopram-treated patients with major depression and 32 healthy control were assayed, Hamilton Depression scale (HAMD) and Hamilton Anxiety Scale (HAMA) were assessed. We then measured 5-HT in platelet, in platelet-poor plasma and in the nuclei of brain tissues obtained from chronic unpredictable mild stress (CUMS) rats with or without citalopram treatment, and from the controls rats that were treated with vehicle. Toward this end, we analyzed whether correlations exist between platelet and brain.

RESULTS

No differences were observed among drug-naïve patients, citalopram-treated patients and health control according to gender and age (p>0.05). Drug-naïve depressed patients had highest scores in HAMD and HAMA among the three groups (F=223.3, p<0.01; F=70.7, p<0.01, respectively) Citalopram-treated patients had significantly lower platelet 5-HT levels,compared to control subjects (Mean 58.1±36.8ng/10(9) versus 558.0±199.4ng/10(9), p<0.01) and compared to drug-naïve patients (Mean 58.1 ±36.8ng/10(9) versus 646.4±259.0ng/10(9), p<0.01), while drug-naïve patients had similar 5-HT platelet concentrations as controls(p>0.05). Consistent with clinical results, in comparison with control (1473.4±391.0ng/10(9)) and drug-naive CUMS rats (1559.0±424.4ng/10(9)), the citalopram-treated CUMS rats (684.2±335.6ng/10(9)) demonstrated a significant reduction in platelet 5-HT levels (p<0.01), but there were no difference among the three groups in platelet-poor plasma 5-HT(F=0.11, p>0.05). Hippocampal 5-HT levels were higher among CUMS rats treated with saline (98.2±59.0ng/g) than vehicle animals (31.9±18.3ng/g, p<0.01) or citalopram-treated rats (42.1±33.9ng/g, p<0.05); however, 5-HT concentrations in prefrontal cortex and Raphe Nuclei were consistent among citalopram-treated or saline-treated CUMS rats(p>0.05). Furthermore, the levels of platelet 5-HT did not correlate with neuronal 5-HT levels (p>0.05).

LIMITATIONS

Dosages was fix for citalopram-treat rats, and the citalopram-treated vehicle arm did not set up.

CONCLUSIONS

Our study suggests that platelet 5-HT levels might respond to SSRI treatment, but this peripheral index is not a direct reflector of central 5-HT levels.

Serotonin reuptake inhibitors and post-gastrostomy bleeding: reevaluating the link

Introduction

Serotonin reuptake inhibitors (SRIs) are one of the most commonly prescribed classes of medications with a relatively safe side-effect profile. However, SRIs are being increasingly reported to be associated with bleeding complications in patients undergoing invasive procedures resulting from inhibition of serotonin reuptake by platelets and impaired platelet aggregation. The aim of our study was to determine whether there is an increased risk of post-percutaneous endoscopic gastrostomy (PEG) bleeding in patients exposed to SRIs after controlling for other mediations known to increase the risk of bleeding and major comorbidities.

Methods

This was a single-center cohort study that included who underwent PEG tube placement by standard pull-guidewire technique from July 2006 to June 2014. Patients were categorized into groups based on the medications (SRIs, aspirin, non-steroidal anti-inflammatory drugs, and anticoagulants) administered during the index hospitalization. The incidence of post-PEG bleeding was noted in two distinct post-procedure periods: within 48 hours, and between 48 hours and 14 days.

Results

A total of 637 PEG tube placements were done on 570 patients during the study period. There were 107 patients (18.8%) with major bleeding within 48 hours of PEG and 79 patients (13.9%) with major bleeding between 48 hours and 14 days. There was no significant increase in the post-PEG bleeding in patients taking a combination of an SRI along with aspirin or non-steroidal anti-inflammatory drugs. Patients on subcutaneous heparin for prophylaxis against thromboembolic events were more likely to have oozing at the PEG site requiring blood transfusion.

Conclusion

We did not notice an increase in post-PEG bleeding in patients on SRIs. However, in view of the limitation that our study is retrospective and that there are no known significant side effects of withdrawal of SRIs for a short duration, withholding SRIs could be a safe clinical option in patients undergoing PEG tube placement.

Clinical pharmacokinetics and pharmacodynamics of clopidogrel

Acute coronary syndromes (ACS) remain life-threatening disorders, which are associated with high morbidity and mortality. Dual antiplatelet therapy with aspirin and clopidogrel has been shown to reduce cardiovascular events in patients with ACS. However, there is substantial inter-individual variability in the response to clopidogrel treatment, in addition to prolonged recovery of platelet reactivity as a result of irreversible binding to P2Y12 receptors. This high inter-individual variability in treatment response has primarily been associated with genetic polymorphisms in the genes encoding for cytochrome (CYP) 2C19, which affect the pharmacokinetics of clopidogrel. While the US Food and Drug Administration has issued a boxed warning for CYP2C19 poor metabolizers because of potentially reduced efficacy in these patients, results from multivariate analyses suggest that additional factors, including age, sex, obesity, concurrent diseases and drug-drug interactions, may all contribute to the overall between-subject variability in treatment response. However, the extent to which each of these factors contributes to the overall variability, and how they are interrelated, is currently unclear. The objective of this review article is to provide a comprehensive update on the different factors that influence the pharmacokinetics and pharmacodynamics of clopidogrel and how they mechanistically contribute to inter-individual differences in the response to clopidogrel treatment.

Adverse drug reactions and drug-drug interactions with over-the-counter NSAIDs

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen have a long history of safe and effective use as both prescription and over-the-counter (OTC) analgesics/antipyretics. The mechanism of action of all NSAIDs is through reversible inhibition of cyclooxygenase enzymes. Adverse drug reactions (ADRs) including gastrointestinal bleeding as well as cardiovascular and renal effects have been reported with NSAID use. In many cases, ADRs may occur because of drug-drug interactions (DDIs) between the NSAID and a concomitant medication. For example, DDIs have been reported when NSAIDs are coadministered with aspirin, alcohol, some antihypertensives, antidepressants, and other commonly used medications. Because of the pharmacologic nature of these interactions, there is a continuum of risk in that the potential for an ADR is dependent on total drug exposure. Therefore, consideration of dose and duration of NSAID use, as well as the type or class of comedication administered, is important when assessing potential risk for ADRs. Safety findings from clinical studies evaluating prescription-strength NSAIDs may not be directly applicable to OTC dosing. Health care providers can be instrumental in educating patients that using OTC NSAIDs at the lowest effective dose for the shortest required duration is vital to balancing efficacy and safety. This review discusses some of the most clinically relevant DDIs reported with NSAIDs based on major sites of ADRs and classes of medication, with a focus on OTC ibuprofen, for which the most data are available.

Bioprofiling of platelets in medicated patients with depression

BACKGROUND

Changes in platelet bioactivity and aggregation are of interest when studying patients with depression as this could help to explain the statistically observed association of depression and chronic somatic, especially cardiovascular disease. This link could potentially be mediated through serotonergic signaling or immunological changes.

METHODS

38 medicated patients with major depressive disorder (MDD) and 30 mentally healthy controls, both without a diagnosis of cardiovascular disease, were included in this naturalistic study. Demographic and psychometric data were obtained. Platelet aggregability was measured by PFA-100 and bioactive compounds and serotonin levels were quantified in platelet sonicate.

RESULTS

The comparison of patients with controls revealed no changes in platelet aggregability, but significant differences in platelet content of several bioactive compounds. In a second analysis, patients were grouped according to the receptors and transporters influenced by their medication and again compared to controls. A significant effect of MDD was found for platelet content of serotonin, CD40L, interleukin-1β, and platelet factor-4, independent of medication. These markers can thus be classified as sensitive to MDD. The effect of medication on platelet parameters was also evaluated. Platelet content of matrix metalloproteinase-2 and β-thromboglobulin was normalized in MDD patients by medication acting on the serotonin transporter.

LIMITATIONS

Owing to the naturalistic study design, patients were on a variety of different medications and combination therapies. This was accounted for by a novel analysis method.

CONCLUSION

Platelet serotonin levels and content of immunomodulatory compounds are significantly altered in patients with MDD, even if treatment effects are taken into account.