5-HT3 Antagonist Research Articles

Predicting biological activity and design of 5-HT6 antagonists through assessment of ANN-QSAR models in the context of Alzheimer's disease.

Alzheimer's disease (AD) is the leading cause of dementia around the world, totaling about 55 million cases, with an estimated growth to 74.7 million cases in 2030, which makes its treatment widely desired. Several studies and strategies are being developed considering the main theories regarding its origin since it is not yet fully understood. Among these strategies, the 5-HT6 receptor antagonism emerges as an auspicious and viable symptomatic treatment approach for AD. The 5-HT6 receptor belongs to the G protein-coupled receptor (GPCR) family and is closely implicated in memory loss processes. As a serotonin receptor, it plays an important role in cognitive function. Consequently, targeting this receptor presents a compelling therapeutic opportunity. By employing antagonists to block its activity, the 5-HT6 receptor's functions can be effectively modulated, leading to potential improvements in cognition and memory. Addressing this challenge, our research explored a promising avenue in drug discovery for AD, employing Artificial Neural Networks-Quantitative Structure-Activity Relationship (ANN-QSAR) models. These models have demonstrated great potential in predicting the biological activity of compounds based on their molecular structures. By harnessing the capabilities of machine learning and computational chemistry, we aimed to create a systematic approach for analyzing and forecasting the activity of potential drug candidates, thus streamlining the drug discovery process. We assembled a diverse set of compounds targeting this receptor and utilized density functional theory (DFT) calculations to extract essential molecular descriptors, effectively representing the structural features of the compounds. Subsequently, these molecular descriptors served as input for training the ANN-QSAR models alongside corresponding biological activity data, enabling us to predict the potential efficacy of novel compounds as 5-hydroxytryptamine receptor 6 (5-HT6) antagonists. Through extensive analysis and validation of ANN-QSAR models, we identified eight new promising compounds with therapeutic potential against AD.

Concept article: Antidepressant-induced destabilization in bipolar illness mediated by serotonin 3 receptor (5HT3).

Antidepressants used by patients with bipolar disorder have been associated with destabilization with an increase in mania, depression, and cycling. The most commonly proposed mechanism, that antidepressants 'overshoot' their antidepressant effect to create a manic or mixed state, is unlikely since antidepressants have actually been found to be ineffective in treating bipolar depression. Beginning with known bipolar-specific pathophysiologic abnormalities provides the greatest likelihood of insight. PubMed was queried with 'bipolar', 'sodium', 'intracellular sodium', 'serotonin 3', '5HT3', '5-hydroxytryptamine type 3 receptors', and 'antidepressant' either individually or in combination. Pathologic mood states (both mania and depression) are associated with increased intracellular sodium (Na) concentrations that depolarize the resting membrane potential to increase cellular excitability (mania) or cause depolarization block (depression). Stimulation of the serotonin (5HT) receptors depolarizes the post-synaptic neuron. Stimulation of 5HT3 may be of particular importance since it is coupled to a cation channel that directly depolarizes the membrane. These effects directly impact the physiology of patients with bipolar disorder to alter neuronal excitability in a fashion that worsens both mania and depression. The most consistently observed biological abnormality in individuals going through mania or bipolar depression involves a decline in Na pump activity, with consequent elevation of intracellular Na levels. Antidepressant treatment potentiates this, particularly by activation of 5HT3. This hypothesis can be tested by coadministering a 5HT3 antagonist (e.g., vortioxetine or ondansetron) to achieve blockade of that receptor while treating bipolar depression with a serotoninergic antidepressant.

Focal pharmacological manipulation of serotonin signaling in the amygdala does not alter social behavior.

Serotonin signaling plays critical roles in social and emotional behaviors. Likewise, decades of research demonstrate that the amygdala is a prime modulator of social behavior. Permanent excitotoxic lesions and transient amygdala inactivation consistently increase social behaviors in non-human primates. In rodents, acute systemic administration of drugs that increase serotonin signaling is associated with decreased social interactions. However, in primates, the direct involvement of serotonin signaling in the amygdala, particularly in affiliative social interaction, remains unexplored. Here, we examined the effects of serotonin manipulations within the amygdala on social behavior in eight pairs of familiar male macaques. We microinfused drugs targeting the serotonin system into either the basolateral (BLA) or central (CeA) amygdala and measured changes in social behavior. Surprisingly, the results demonstrated no significant differences in social behavior following the infusion of a selective serotonin reuptake inhibitor, 5-HT1A agonist or antagonist, 5-HT2A agonist or antagonist, or 5-HT3 agonist or antagonist into either the BLA or CeA. These findings suggest that serotonin signaling in the amygdala does not directly contribute to the regulation of social behavior between familiar conspecifics. Future research should explore alternative mechanisms and potential interactions with other brain regions to gain a comprehensive understanding of the complex neural circuitry governing social behavior.

Differential roles of serotonin receptor subtypes in regulation of neurotrophin receptor expression and intestinal hypernociception.

Aberrant serotonin (5-hydroxytryptamine, 5-HT) metabolism and neurite outgrowth were associated with abdominal pain in irritable bowel syndrome (IBS). We previously demonstrated that 5-HT receptor subtype 7 (5-HT₇) was involved in visceral hypersensitivity of IBS-like mouse models. The aim was to compare the analgesic effects of a novel 5-HT₇ antagonist to reference standards in mouse models and investigate the mechanisms of 5-HT₇-dependent neuroplasticity. Two mouse models, including Giardia post-infection combined with water avoidance stress (GW) and post-resolution of trinitrobenzene sulfonic acid-induced colitis (PT) were used. Mice were orally administered CYY1005 (CYY, a novel 5-HT₇ antagonist), alosetron (ALN, a 5-HT₃ antagonist), and loperamide (LPM, an opioid receptor agonist) prior to measurement of visceromotor responses (VMR). Levels of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin receptors (NTRs) were assessed. Peroral CYY was more potent than ALN or LPM in reducing VMR values in GW and PT mice. Increased mucosal 5-HT₇-expressing nerve fibers were associated with elevated Gap43 levels in the mouse colon. We observed higher colonic Ntrk2 and Ngfr expression in GW mice, and increased Bdnf expression in PT mice compared with control mice. Human SH-SY5Y cells stimulated with mouse colonic supernatant or exogenous serotonin exhibited longer nerve fibers, which CYY dose-dependently inhibited. Serotonin increased Ntrk1 and Ngfr expression via 5-HT₇ but not 5-HT₃ or 5-HT₄, while Ntrk2 upregulation was dependent on all three 5-HT receptor subtypes. Stronger analgesic effects by peroral CYY were observed compared with reference standards in two IBS-like mouse models. The 5-HT₇-dependent NTR upregulation and neurite elongation may be involved in intestinal hypernociception.

Serotonin receptor-mediated vasorelaxation occurs primarily through 5-HT4 activation in bovine lateral saphenous vein.

To better understand mechanisms of serotonin- (5-HT) mediated vasorelaxation, isolated lateral saphenous veins from cattle were assessed for vasoactivity using myography in response to increasing concentrations of 5-HT or selective 5-HT receptor agonists. Vessels were pre-contracted with 1 × 10-4 M phenylephrine and exposed to increasing concentrations of 5-HT or 5-HT receptor agonists that were selective for 5-HT1B, 5-HT2B, 5-HT4, and 5-HT7. Vasoactive response data were normalized as a percentage of the maximum contractile response induced by the phenylephrine pre-contraction. At 1 × 10-7 M 5-HT, a relaxation was observed with an 88.7% decrease (p < 0.01) from the phenylephrine maximum. At 1 × 10-4 M 5-HT, a contraction was observed with a 165% increase (p < 0.01) from the phenylephrine maximum. Increasing concentrations of agonists selective for 5-HT2B, 5-HT4, or 5-HT7 resulted in a 27%, 92%, or 44% (p < 0.01) decrease from the phenylephrine maximum, respectively. Of these 5-HT receptor agonists, the selective 5-HT4 receptor agonist resulted in the greatest potency (-log EC50) value (6.30) compared with 5-HT2B and 5-HT7 receptor agonists (4.21 and 4.66, respectively). To confirm the involvement of 5-HT4 in 5-HT-mediated vasorelaxation, blood vessels were exposed to either DMSO (solvent control) or a selective 5-HT4 antagonist (1 × 10-5 M) for 5-min prior to the phenylephrine pre-contraction and 5-HT additions. Antagonism of the 5-HT4 receptor attenuated the vasorelaxation caused by 5-HT. Approximately 94% of the vasorelaxation occurring in response to 5-HT could be accounted for through 5-HT4, providing strong evidence that 5-HT-mediated vasorelaxation occurs through 5-HT4 activation in bovine peripheral vasculature.

Pharmacological treatment of cancer pain and opioid induced nausea and vomiting: online survey and comparison with current guidelines

PurposeWe assumed that in Palliative Care, even in common clinical situations, the choice of drugs differs substantially between physicians. Therefore, we assessed the practice of pharmaceutical treatment choices of physicians for cancer pain and opioid-induced nausea and vomiting (OINV) and the rationale for their choices.MethodsAn online survey was conducted with physicians covering the following domains: i) Cancer pain therapy: non-opioids in addition to opioids: choice of drug ii) prevention of OINV: choice of drug and mode of application. Current guidelines concerning cancer pain therapy and prevention of OINV were compared.ResultsTwo-hundred-forty European physicians responded to our survey. i) Use of non-opioids in addition to opioids for the treatment of cancer pain: Only 1.3% (n = 3) of respondents never used an additional non-opioid. Others mostly used: dipyrone/metamizole (49.2%, n = 118), paracetamol/acetaminophen (34.2%, n = 82), ibuprofen / other NSAIDs (11.3%, n = 27), specific Cox2-inhibitors (2.1%, n = 5), Aspirin (0.4%, n = 1), no answer (2.9%, n = 7). ii) Antiemetics to prevent OINV: The drugs of choice were metoclopramide (58.3%, n = 140), haloperidol (26.3%, n = 63), 5-HT3 antagonists (9.6%, n = 23), antihistamines (1.3%, n = 3) and other (2.9%, n = 7); no answer (1.7%, n = 4). Most respondents prescribed the substances on-demand (59.6%, n = 143) while others (36.3%, n = 87) provided them as around the clock medication. Over both domains, most physicians answered that their choices were not based on solid evidence from randomized controlled trials (RCTs). Guidelines were inconsistent regarding if and what non-opioid to use for cancer pain and recommend anti-dopaminergic drugs for prevention or treatment of OINV.ConclusionsPhysician’s practice in palliative care for the treatment of cancer pain and OINV differed substantially. Respondents expressed the lack of high-quality evidence- based information from RCTs. We call for evidence from methodologically high-quality RCTs to be available to inform physicians about the benefits and harms of pharmacological treatments for common symptoms in palliative care.

Low-dose ondansetron: A candidate prospective precision medicine to treat alcohol use disorder endophenotypes

BackgroundAlcohol use disorder (AUD) is among the leading causes of morbidity and mortality worldwide, and over 95 million people live with alcohol dependence globally. The estimated heritability of AUD is 50–60 %, and multiple genes are thought to contribute to various endophenotypes of the disease. Previous clinical trials support a precision medicine approach using ondansetron (AD04, a 5-HT3 antagonist) by segregating AUD populations by the bio-genetic endophenotype of specific serotonergic genotypes and the bio-psychosocial endophenotype of the severity of drinking or both. By targeting the modulation of biogenetic signaling within the biopsychosocial context of AUD, low-dose AD04 holds promise in reducing alcohol consumption among affected individuals while minimizing adverse effects. MethodsThis was a phase III, 6-month, 25-site, randomized, placebo-controlled clinical trial using AD04 to treat DSM-V–categorized AUD individuals who were pre-stratified into the endophenotypes of heavy or very heavy drinking individuals and possessed a pre-defined profile of genetic variants related to the serotonin transporter and serotonin-3AB receptor. Participants (N = 303) presented moderate to severe AUD, >80 % were men, mostly in their fifties, and >95 % were of European descent. Low-dose AD04 (approx. 033 mg twice daily) or a matching placebo was administered twice daily for 6 months. Brief Behavioral Compliance Enhancement Treatment (BBCET [53]) was administered every two weeks to enhance medication compliance and clinic attendance. ResultsThere was a significant reduction in the monthly percentage of heavy drinking days, PHDD (-46·7 % (2·7 %), 95 %CI: -52·1 % to -41·2 % vs. -38·1 % (2·9 %), 95 %CI: -43·8 % to -32·5 %, respectively; LS mean difference=-8·5 %; p = 0.03) among AD04-treated vs. placebo-receiving heavy drinking individuals at month 6. Heavy drinking individuals were also less likely to be diagnosed with AUD [Month 1: -32·0 % (2·8 %), 95 %CI: -37·5 % to -26·5 % vs. -23·2 % (2·9 %), 95 %CI: -28·9 to -17·5 %; LS mean difference= -8·8 %; p = 0·026)], and improved on the WHO quality of life BREF scale with a significant effect for at least a 1-level downward shift (OR = 3.4; 95 % CI: 1·03–11·45, p = 0·044). Importantly, heavy drinking individuals, as distinct from very heavy drinking individuals, were the bio-psychosocial endophenotype more predictive of therapeutic response to AD04. AD04 had an exceptional safety and tolerability profile, like the placebo's. ConclusionsIn this Phase 3 clinical trial, AD04 was shown to be a promising treatment for currently drinking heavy drinking individuals with AUD who also possess a specific genotypic profile in the serotonin transporter and serotonin-3AB receptor complex. Using AD04 to reduce the harm of AUD in heavy drinking individuals who are currently drinking, without the necessity of abstinence or detoxification from alcohol use, is an important advance in the field of precision medicine. AD04’s adverse events profile, which was like placebo, should enhance accessibility and acceptance of modern medical treatment for AUD by lowering the incorrect but commonly perceived stigma of personal failure.

Increased Postoperative Opioid Consumption in the Presence of Coadministration of 5-Hydroxytryptamine Type 3 Antagonists with Acetaminophen: A Hospital Registry Study.

Acetaminophen and 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists are administered as standard prophylaxes for postoperative pain, nausea, and vomiting. Preclinical studies, however, suggest that 5-HT3 antagonists may compromise acetaminophen's analgesic effect. This hospital registry study investigates whether 5-HT3 antagonists mitigate the analgesic effect of prophylactic acetaminophen in a perioperative setting. This study included 55,016 adult patients undergoing general anesthesia for ambulatory procedures at a tertiary healthcare center in Massachusetts from 2015 to 2022. Using binary exposure variables and a comprehensive selection of preplanned patient- and procedure-related covariates for confounder control, the authors investigated whether intraoperative 5-HT3 antagonists affected the association between pre- or intraoperative acetaminophen and postoperative opioid consumption, gauged by opioid dose in milligram oral morphine equivalents (OME) administered in the postanesthesia care unit. A multivariable, zero-inflated negative binomial regression model was applied. A total of 3,166 patients (5.8%) received only acetaminophen, 15,438 (28.1%) only 5-HT3 antagonists, 31,850 (57.9%) both drugs, and 4,562 (8.3%) neither drug. The median postanesthesia care unit opioid dose was 7.5 mg OME (interquartile range, 7.5 to 14.3 mg OME) among 16,640 of 55,016 (30.2%) patients who received opioids, and the mean opioid dose was 3.2 mg OME across all patients (maximum cumulative dose, 20.4 mg OME). Acetaminophen administration was associated with a -5.5% (95% CI, -9.6 to -1.4%; P = 0.009; adjusted absolute difference, -0.19 mg OME; 95% CI, -0.33 to -0.05; P = 0.009) reduction in opioid consumption among patients who did not receive a 5-HT3 antagonist, while there was no effect in patients who received a 5-HT3 antagonist (adjusted absolute difference, 0.00 mg OME; 95% CI, -0.06 to 0.05; P = 0.93; P for interaction = 0.013). A dose-dependent association of pre- or intraoperative acetaminophen with decreased postoperative opioid consumption was not observed when 5-HT3 antagonists were coadministered, suggesting that physicians might consider reserving 5-HT3 antagonists as rescue medication for postoperative nausea or vomiting when acetaminophen is administered for pain prophylaxis.

Use of vortioxetine in treating obsessive-compulsive disorder: a case report

Introduction Obsessive-compulsive disorder (OCD) is a chronic disorder with a wide range of manifestations but primarily intrusive thoughts (obsessions) and/or ritualized actions (compulsions) that can cause a huge distress in patients’ life. First-line treatment for OCD are selective serotonin reuptake inhibitors (SSRIs). Tricyclic antidepressants are used as second-line treatment due to secondary effects. Also antipsychotics such as aripiprazole are approved for treating OCD. Vortioxetine is has 5-HT3, 5-HT7 and 5-HT1D antagonists, 5-HT1B partial agonist and a 5-HT1A agonist and serotonin transporter inhibitor property. It is used in major depressive and anxiety disorders. A male 48 years old patient with an OCD diagnosis since he was 21, was reffered to psychiatry department. Previously, he had no response with SSRIs at full dosage and clomipramine 75mg was effective. At 46 years old, he had an acute myocardial infarction. He also admited not taking the medication regularly due to sexual disfunction and having affective symptoms related to the distress caused by OCD.ObjectivesTo evaluate efficacy of vortioxetine in treating OCD in a patient with contraindications for tricyclic antidepressants and no response to SSRIs.MethodsClomipramine dose was reduced until discontinuation. After one week without treatment, basal scores for Hamilton Scale and Dimensional Yale-Brown Obsessive-Compulsive Scale (DY-BOCS) were collected. Same data was collected again after 10 weeks treatment.ResultsThe dosage of vortioxetine was progressively titrated until 20mg daily in 3 weeks lapse. Diazepam 5mg was added in case of insomnia or anxiety. Aripiprazole 5mg was added in the third week of treatment as adjunctive treatment due to the recurrence of some intrusive thoughts (discontinued by himself because of akathisia). Finally, the patient reported an improvement in affective and OCD symptoms in the sixth week of treatment that was sustained until the tenth week, when data was recollected. The patient did not refer sexual disfunction.The pre and post results are summarized in tables 1 and 2. Table 1.Hamilton Depresion Rating Scale (0-52)BasalPost 10-week treatment214Dimensional Y-BOCS (0-15)BasalPost 10-week treatmentAggressive-related obsessions and compulsions102Religious-related obsessions and compulsions51Symmetry and order71Pollution and cleaning00Collecting and accumulation20Miscellaneous103ConclusionsVortioxetine might be a promising molecule for treating OCD in patients with contraindications for first and second-line treatments.Disclosure of InterestNone Declared

Safety and compliance of long-term low-dose ondansetron in alcohol use disorder treatment.

BackgroundThe increasing prevalence of alcohol use disorder (AUD) and the parallel surge in alcohol-associated liver disease (ALD) emphasize the urgent need for comprehensive alcohol management strategies. Low-dose ondansetron (AD04, a 5-HT3 antagonist) was shown recently to be a promising treatment for AUD with a specific genotypic profile (5-marker). The liver safety of AD04 has never been evaluated in subjects with AUD. The aim of the present study was to assess the liver safety profile of AD04 compared with placebo in subjects with AUD. MethodsLiver biochemical parameters were assessed in subjects with AUD with a 5-marker genetic profile who participated in a Phase 3 randomized controlled trial and received either twice-daily, low-dose AD04 (ondansetron 0.33 mg twice daily) or matching placebo, combined with brief psychosocial counseling. ALT, AST, GGT, Serum Bilirubin, MCV, and Prothrombin were evaluated at weeks 0, 12, and 24. Adverse cardiac events, general well-being, and study completion were also assessed. ResultsLow-dose AD04 did not significantly change biochemical markers of liver injury, such as ALT, AST, and Serum Bilirubin. While patients with AUD displayed elevated GGT levels, typically associated with increased alcohol consumption, this parameter remained unaffected by low-dose AD04. Notably, no significant adverse effects were observed due to oral low-dose AD04 treatment. ConclusionsLow-dose AD04 has the potential to be a safe treatment option for subjects with AUD and ALD, indicating the need for an RCT for this specific cohort. Such a trial would pave the way for the design of a precision treatment for combined AUD with ALD.

Ondansetron attenuates cisplatin-induced behavioral and cognitive impairment through downregulation of NOD-like receptor inflammasome pathway

Cisplatin is an effective and commonly used chemotherapeutic drug; however, its use is accompanied by several adverse effects, including chemobrain. Ondansetron is a 5-HT3 antagonist, commonly used in prophylactic against chemotherapy-induced nausea and vomiting. Moreover, it has been identified as a novel neuroprotective agent in different animal models. However, its protective role against chemotherapy-induced chemobrain has not been investigated. The current study was the first study that explored the potential neuroprotective effect of ondansetron against cisplatin-induced chemobrain in rats. Cisplatin (5 mg/Kg) was injected intraperitoneally, once weekly, for 4 weeks with the daily administration of ondansetron (0.5 and 1 mg/Kg). Compared to the cisplatin-treated group, ondansetron administration showed a significant decrease in the latency time and a significant increase in ambulation, rearing, and grooming frequency in the open field test (OFT). Moreover, a significant improvement in the latency time in the rotarod and passive avoidance tests, following ondansetron administration. In addition, ondansetron treatment increased the percentage of alternation in the Y-maze test. Also, ondansetron showed a remarkable enhancement in the biochemical parameters in the hippocampus. It increased the acetylcholine (Ach) level and decreased the level of the acetylcholine esterase enzyme (AchE). Ondansetron significantly decreased interleukin-1β (Il-1β), tumor necrosis factor-alpha (TNF-α), toll-like receptor-4 (TLR-4), NOD-like receptor-3 (NLRP3) inflammasome as well as caspase-1 and caspase-3 levels. Furthermore, ondansetron significantly decreased the levels of copper transporter-1(CTR1) expression in the hippocampus. Collectively, these findings suggest that ondansetron may exhibit a neuroprotective and therapeutic activity against cisplatin-induced chemobrain.

Journal of Clinical Gastroenterology Lectureship Dubai 2022 : Management of Irritable Bowel Syndrome With Diarrhea.

Irritable bowel syndrome (IBS) with diarrhea (IBS-D) affects ~1% of the general population and is characterized by abdominal pain associated with diarrhea. IBS-D symptoms significantly impact the quality of life of patients. Major uncertainties remain regarding the optimal management of these patients. Several therapies have been investigated over the years for the treatment of IBS-D. In the initial management, commonly prescribed approaches with an effect on global IBS symptoms include a low Fermentable Oligo-, Di-, Mono-Saccharides and Polyols diet and probiotics, while antispasmodics are used for targeting abdominal pain and loperamide for diarrhea only. Additional therapeutic options for the relief of global IBS symptoms include rifaximin, 5-HT 3 antagonists, gut-directed psychological therapies, and eluxadoline, while tricyclic antidepressants can target abdominal pain and bile acid sequestrants diarrhea. Promising evidence exists for the use of mesalazine and fecal microbiota transplantation in IBS-D, although further evidence is needed for definitive conclusions regarding their efficacy.

Quantum mechanical parameters-based study of aryl sulphonamides as 5-HT6 serotonin ligand using DFT methods

In the present work, quantum mechanical descriptors have been used for the development of quantitative structure activity relationship (QSAR) models for the thirty-two derivatives of aryl sulphonamide and sulfone based 5-HT6 antagonists. Among several classes of serotonin 5-HT6 receptor ligands, aryl sulphonamides reported better affinity towards the receptor. Drugs acting as serotonin ligands are useful in the treatment of a variety of mental disorders. The descriptors that have been used in our study are total energy, log P, molecular weight, dipole moment, heat of formation, LUMO energy, HOMO energy and electrophilicity index. The geometry optimization and evaluation of descriptors of all the compounds has been done with the help of CAChe Pro software using DFT-B88-LYP method with double-zeta valence polarized (DZVP) basis set. The best QSAR model for this set of derivatives has been obtained by combination of descriptors molecular weight, dipole moment and heat of formation. The descriptor molecular weight gives a mono-parametric QSAR model with remarkable predictive ability with positive contribution. The descriptor molecular weight is present in all best bi-parametric and tri-parametric QSAR models. Statistical parameters such as correlation coefficient, cross validation coefficient, standard error etc. were used to validate the predictability of QSAR models.

Understanding Australian Pharmacists’ Perceptions on the Utilisation of Oral 5-HT3 Antagonists as Pharmacist-Only Anti-Emetics in Comparison to Oral D2 Antagonists

Objectives: To investigate the perception of community pharmacists on the down-scheduling of 5-HT3 antagonists to pharmacist-only-medicine for treatment of acute nausea and/or vomiting in Australia. Methods: A nationwide anonymous survey targeting Australian community pharmacists was conducted from April to May 2023. Responses were collected and analysed quantitively or qualitatively, where appropriate. Key findings: Participants reported that 5-HT3 antagonists were effective at treating nausea and/or vomiting and would likely recommend their use. Training is required to manage supply due to concerns related to their side effects. Conclusion: Participants supported down-scheduling of 5-HT3 antagonists for the treatment of nausea and/or vomiting in Australia. A pilot study on the provision of 5-HT3 antagonists by pharmacists is recommended as is the development of guidelines for pharmacist-only supply before down-scheduling is considered.

Which 5-HT3 antagonist prevents nausea and vomiting in cesarean section more effectively: a network meta-analysis.

Selective 5-hydroxytryptamine 3 receptor (5-HT3) antagonists are commonly used to prevent nausea and vomiting (NV) after cesarean section, but the comparative efficacy of different 5-HT3 antagonists remains unclear. This network meta-analysis aimed to determine which 5-HT3 antagonists might be the preferred choice for preventing NV in parturient scheduled for elective cesarean delivery under spinal anesthesia. PubMed, EMBASE, Cochrane library, and Web of Science were searched for relevant randomized controlled trials (RCTs) published before August 24, 2023. Random network meta-analysis was performed using Stata 14.0 to estimate the efficacy of different 5-HT3 antagonists in preventing intra- and post-operative NV. Twenty-eight studies involving seven dosing regimens of three 5-HT3 antagonists were included. Pooled results showed that ondansetron 12 mg was superior to other six dosing regimens in the prevention of postoperative NV (PONV), PON, and POV, with the ranking probability of 80.2%, 95.8%, and 87.7%, respectively, followed by granisetron two mg. Ondansetron 4 mg might be the first choice for preventing intraoperative NV (IONV) (92.8%), with the least use of postoperative rescue antiemetics (90.6%). Granisetron 3 mg and tropisetron 2 mg might be the best options for preventing ION and IOV, respectively. Based on available data, ondansetron 12 mg may have the best efficacy in preventing PONV, PON, and POV. Additionally, more studies are warranted to compare the safety of ondansetron 12 mg versus granisetron two mg.

Appraising and highlighting gaps among prophylactic intervention studies for reducing the incidence of postoperative nausea and vomiting in children: a systematic review

ObjectivesPostoperative nausea and vomiting (PONV) is a leading perioperative morbidity outcome following general anaesthesia. This systematic review aims to identify, appraise and summarise the evidence synthesis studies of prophylactic interventions...

5-HT3 antagonist, tropisetron, ameliorates age-related renal injury induced by D-galactose in male mice: Up-regulation of sirtuin 1.

The kidney ages faster than other organs due to changes in energy metabolism, mitochondrial dysfunction, and oxidative stress. This study looked into the anti-aging effect of tropisetron. D-galactose was administrated subcutaneously in a mouse model for eight weeks in order to induce renal aging. Three separate intraperitoneal doses of tropisetron (1, 3, and 5 mg/kg body weight) were given at the same time. We assessed markers of mitochondrial dysfunction, oxidative stress, and inflammation. Via Real-Time PCR, the expressions of genes linked to aging (SIRT1) and apoptosis (Bax and Bcl-2) were ascertained. In addition, an assessment of histopathological changes, blood urea nitrogen, and creatinine concentrations was done. In kidney tissue, tropisetron reduces mitochondrial dysfunction and oxidative stress, which are caused by D-galactose-induced overproduction of inflammatory mediators. Additionally, tropisetron demonstrated antiapoptotic activity in renal tissue and augmented the decrease in SIRT1 gene expression associated with D-galactose administration. Besides, tropisetron significantly improved the histological alterations in the renal tissues of aged mice and effectively decreased the elevated levels of creatinine and also blood urea nitrogen. The results provided additional insight into the effect of tropisetron on renal aging and the underlying mechanisms, particularly through its ability to modulate SIRT1 signaling.

5-hydroxytryptamine-evoked contractile activity of large gut in neonatal albino rats

Objectives: Serotonin, also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter. It is abundantly present in the gut of mammals. The extent to which it contributes to the contraction of the neonatal gut requires further investigation. This study aimed to assess the effect of 5-HT on the contractions of the large intestine in newborn albino rats. Materials and Methods: The colon and rectum samples were collected from neonatal and adult albino rats for analysis. Further, in an organ bath, isometric contractions of these isolated gut segments were recorded, in vitro, using a force transducer and a computerised chart recorder, with and without 5-HT in different groups. The 5-HT-induced contractions were also recorded in gut segments pre-treated with various antagonists. Results: 5-HT (0.01–10 μM) caused a significantly (P &lt; 0.05) greater contractile response (g/g wet tissue) in neonate rats as compared to adults. The response was greater in the rectum as compared to the colon in both neonates and adults. In neonate rats, ondansetron, a 5-HT3 antagonist, could not block the 5-HT-induced large gut contractions, while, in adult rats, it significantly blocked the 5-HT-evoked gut contractility. Methysergide, a 5-HT1/2/5-7 antagonist, blocked the response in both the adult and neonate rectum. Conclusion: The 5-HT-evoked response is mediated through 5-HT3 receptor subtypes in adults but not in neonate colon and rectum, indicating possible changes in the distribution of 5-HT receptors in the colon and rectum during development. Furthermore, atropine (a muscarinic cholinergic blocker) and hexamethonium (a ganglion blocker) could not affect the 5-HT-evoked responses in the neonate or adult rats’ colons or rectum. The effect of 5-HT did not appear to involve cholinergic or enteric ganglionic elements.

β-arrestin biased signaling is not involved in the hypotensive actions of 5-HT7 receptor stimulation: use of Serodolin

The 5-hydroxytryptamine 7 receptor (5-HT7) is necessary for 5-HT to cause a concentration-dependent vascular relaxation and hypotension. 5-HT7 is recognized as having biased signaling, transduced through either Gs or β -arrestin. It is unknown whether 5-HT7 signals in a biased manner to cause vasorelaxation/hypotension. We used the recently described β-arrestin selective 5-HT7 receptor agonist serodolin to test the hypothesis that 5-HT7 activation does not cause vascular relaxation or hypotension via the β -arrestin pathway. Isolated abdominal aorta (no functional 5-HT7) and vena cava (functional 5-HT7) from male Sprague Dawley rats were used in isometric contractility studies. Serodolin (1 nM – 10 μM) did not change baseline tone of isolated tissues and did not relax the endothelin-1 (ET-1)-contracted vena cava or aorta. In the aorta, serodolin acted as a 5-HT2A receptor antagonist, evidenced by a rightward shift in 5-HT-induced concentration response curve [pEC50 5-HT [M]: Veh = 5.2 +/- 0.15; Ser (100 nM) = 4.49 +/- 0.08; p < 0.05]. In the vena cava, serodolin acted as a 5-HT7 receptor antagonist, shifting the concentration response curve to 5-HT left and upward (%10 μM NE contraction; Veh = 3.2 +/- 1.7; Ser (10 nM) = 58 +/- 11; p < 0.05) and blocking relaxation of pre-contracted tissue to the 5-HT1A/7 agonist 5-carboxamidotryptamine. In anesthetized rats, 5-HT or serodolin was infused at 5, 25 and 75 μg/kg/min, iv. Though 5-HT caused concentration-dependent depressor responses, serodolin caused an insignificant small depressor responses at all three infusion rates. With the final dose of serodolin on board, 5-HT was unable to reduce blood pressure. Collectively the data indicate that serodolin functions as a 5-HT7 antagonist with additional 5-HT2A blocking properties. 5-HT7 activation does not cause vascular relaxation or hypotension via the β -arrestin pathway.

Investigating the Effect of Serotonin II and III Receptor Inhibitors on the Chronotropic Changes of the Heart to Isoproterenol in Rat Models of Biliary Cirrhosis

Cirrhotic patients have hyperdynamic circulation and at-rest tachycardia, and agents that activate the sympathetic pathway, such as physical practice and pharmacologic stimulations, compared with the normal population, cannot cause enough increase in heartbeat, a condition known as cirrhotic cardiomyopathy. Concerning the presentation of 5-HT2 &amp; 5-HT3 receptors in rat hearts, we used Ketanserin as a 5-HT2 receptor inhibitor &amp; Tropisetron as a 5-HT3 receptor inhibitor to evaluate chronic therapeutic effects of 5-HT2 &amp; 5-HT3 antagonists on the cardiac chronotropic response of cirrhotic rats to adrenergics. Cirrhosis was induced by surgical ligation of the bile duct in Male Wistar rats, and another group remained sham. A week after bile duct ligation or sham surgery, the subjects were given an intraperitoneal injection of either saline or Tropisetron (2 mg/kg). In other BDL &amp; Sharm groups, the subjects were given an intraperitoneal injection of either saline or Ketanserin (6 mg/kg) every other 3 days in the last 3 weeks. Four weeks after bile duct ligation or sham surgery, the atria were isolated and chronotropic responsiveness to Isoproterenol was assessed using a standard organ bath. Our data showed that chronic treatment with Tropisetron (5-HT3 antagonist) in cirrhotic rats could decrease the cardiac chronotropic response. Chronic treatment with Tropisetron can cause a significant decrease in cardiac chronotropic response to Isoproterenol in healthy and cirrhotic rats, even lower than that in cirrhotic rats (without any special treatment). Chronic treatment with Ketanserin cannot change their impaired chronotropic response to Isoproterenol.&#x0D;