Risk of suicide attempts and intentional self-harm on alprazolam.

BACKGROUND: From 2000-2021, U.S. suicide deaths have risen 36 %. Identification of pharmacological agents associated with increased suicide risk and safer alternatives may help reduce this trend. METHODS: An exposure-only within-subject time-to-event pharmacoepidemiologic study of the dynamic association between alprazolam treatment and suicide attempts over 2-years. Parallel analyses were conducted for diazepam, lorazepam and buspirone. Data for 2,495,520 patients were obtained from U.S. private insurance medical claims MarketScan from 2010 to 2019. FINDINGS: Alprazolam was associated with over a doubling of risk of suicide attempts (HR=2.21, 95 % CI=2.06,2.38). A duration-response analysis for the modal dose (0.5 mg) revealed a 5 % increase in suicidal events per additional month of treatment (HR=1.05, 95 % CI=1.04,1.07). Parallel analyses with long-acting (diazepam) and short-acting (lorazepam), found similar associations (diazepam HR=2.87, 95 % CI=2.56,3.21; lorazepam HR=1.83, 95 % CI=1.69,2.00), whereas the non-benzodiazepine anxiolytic, buspirone, showed significantly less risk (HR=1.25, 95 % CI=1.13,1.38), and no increased risk in patients with an attempt history (HR=1.05, 95 % CI=0.70,1.59). INTERPRETATION: This study confirmed an earlier signal linking alprazolam to increased suicide attempt risk. The increased risk extends to benzodiazepines in general, regardless of half-life and risk of withdrawal seizure. Buspirone appears to be a safer treatment than benzodiazepines, particularly in patients at increased risk for suicide.

Gepirone-the latest antidepressant on market state-of-the-art or run-of-the-mill?

Gepirone was recently launched and FDA-approved for MDD. It belongs to azapirones group of psychotropics that is in popular use in Japan and China. Here, author wraps up current knowledge on gepirone contrasted with the older and cheaper anxiolytic buspirone.

Serotonin therapies for opioid-induced disordered swallow and respiratory depression.

Opioids are well-known to cause respiratory depression, but despite clinical evidence of dysphagia, the effects of opioids on swallow excitability and motor pattern are unknown. We tested the effects of the clinically relevant opioid buprenorphine on pharyngeal swallow and respiratory drive in male and female rats. We also evaluated the utility of 5-HT1A agonists (8-OH-DPAT and buspirone) to improve swallowing and breathing following buprenorphine administration. Experiments were performed on 44 freely breathing Sprague-Dawley rats anesthetized with sodium pentobarbital. Bipolar fine wire electrodes were inserted into the mylohyoid, thyroarytenoid, posterior cricoarytenoid, thyropharyngeus, and diaphragm muscles to measure electromyographic (EMG) activity of swallowing and breathing. We evaluated the hypotheses that swallowing varies by stimulus, opioids depress swallowing and breathing, and that 5-HT1A agonists improve these depressions. Our results largely confirmed the following hypotheses: 1) swallow-related EMG activity was larger during swallows elicited by esophageal distension plus oral water infusion than by either stimulus alone. 2) Buprenorphine depressed swallow in both sexes, but females were more susceptible to total swallow suppression. 3) Female animals were also more vulnerable to opioid-induced respiratory depression. 4) 8-OH-DPAT rescued breathing following buprenorphine-induced respiratory arrest, and pretreatment with the partial 5-HT1A agonist buspirone prevented buprenorphine-induced respiratory arrest in female animals. 5) 8-OH-DPAT enhanced mylohyoid and thyropharyngeus EMG amplitude during swallow but did not restore excitability of the swallow pattern generator following total suppression by buprenorphine. Our results highlight sex-specific and behavior-specific effects of buprenorphine and provide preclinical evidence of a 5HT1A agonist for the treatment of respiratory depression and dysphagia.NEW & NOTEWORTHY This is the first study, to our knowledge, to evaluate sex-specific effects of opioid administration on pharyngeal swallow. We expand on a small but growing number of studies that report a lower threshold for opioid-induced respiratory depression in females compared with males, and we are the first to produce this effect with the partial µ-opioid-receptor agonist buprenorphine. This is the first demonstration, to our knowledge, that activation of 5-HT1A receptors can improve swallow and breathing outcomes following systemic buprenorphine administration.

Buspirone and Zolmitriptan Combination for Dyskinesia: A Randomized, Controlled, Crossover Study.

BACKGROUND: Preclinical evidence suggests that co-administration of the 5-HT1A agonist buspirone and the 5-HT1B/1D agonist zolmitriptan act synergistically to reduce dyskinesia to a greater extent than that achieved by either drug alone. OBJECTIVES: Assess the therapeutic potential of a fixed-dose buspirone and zolmitriptan combination in Parkinson's disease (PD) patients with levodopa-induced dyskinesia. METHODS: Single-center, randomized, placebo-controlled, two-way crossover study (NCT02439203) of a fixed-dose buspirone/zolmitriptan regimen (10/1.25 mg three times a day) in 30 patients with PD experiencing at least moderately disabling peak-effect dyskinesia. RESULTS: Seven days of treatment with buspirone/zolmitriptan added to levodopa significantly reduced dyskinesia as assessed by Abnormal Involuntary Movement Scale scores versus placebo (mean treatment effect vs. placebo: -4.2 [-6.1, -2.3]) without significantly worsening Unified Parkinson's Disease Rating Scale (UPDRS) Part III (ON) scores (mean treatment effect vs. placebo: 0.6 [-0.1, 1.3]). No serious adverse events were reported. CONCLUSIONS: In this proof-of-concept study, addition of buspirone/zolmitriptan to the patients' PD medication regimen significantly reduced dyskinesia severity without worsening motor function. © 2024 International Parkinson and Movement Disorder Society.

Inhibitory Actions of Antidepressants, Hypnotics, and Anxiolytics on Recombinant Human Acetylcholinesterase Activity.

Alzheimer's disease (AD) is accompanied by behavioral and psychological symptoms of dementia (BPSD), which is often alleviated by treatment with psychotropic drugs, such as antidepressants, hypnotics, and anxiolytics. If these drugs also inhibit acetylcholinesterase (AChE) activity, they may contribute to the suppression of AD progression by increasing brain acetylcholine concentrations. We tested the potential inhibitory effects of 31 antidepressants, 21 hypnotics, and 12 anxiolytics on recombinant human AChE (rhAChE) activity. At a concentration of 10-4 M, 22 antidepressants, 19 hypnotics, and 11 anxiolytics inhibited rhAChE activity by <20%, whereas nine antidepressants (clomipramine, amoxapine, setiptiline, nefazodone, paroxetine, sertraline, citalopram, escitalopram, and mirtazapine), two hypnotics (triazolam and brotizolam), and one anxiolytic (buspirone) inhibited rhAChE activity by ≥20%. Brotizolam (≥10-6 M) exhibited stronger inhibition of rhAChE activity than the other drugs, with its pIC50 value being 4.57 ± 0.02. The pIC50 values of the other drugs were <4, and they showed inhibitory activities toward rhAChE at the following concentrations: ≥3 × 10-6 M (sertraline and buspirone), ≥10-5 M (amoxapine, nefazodone, paroxetine, citalopram, escitalopram, mirtazapine, and triazolam), and ≥3 × 10-5 M (clomipramine and setiptiline). Among these drugs, only nefazodone inhibited rhAChE activity within the blood concentration range achievable at clinical doses. Therefore, nefazodone may not only improve the depressive symptoms of BPSD through its antidepressant actions but also slow the progression of cognitive symptoms of AD through its AChE inhibitory actions.

Buspirone for the treatment of anxiety in Williams syndrome: a retrospective chart review study.

BACKGROUND: Williams syndrome (WS) is a rare genetic disorder associated with a high prevalence of anxiety disorders. Evidence-based pharmacologic treatments for anxiety in WS are lacking. The purpose of this study is to provide naturalistic data on the use of buspirone for the treatment of anxiety in WS. RESEARCH DESIGN AND METHODS: Medical records of 24 individuals with Williams syndrome (ages 7-47 years) and anxiety who received treatment with buspirone were reviewed. Treatment response to buspirone was rated by assigning a retrospective Clinical Global Impression Improvement subscale (CGI-I) score. RESULTS: Twenty-three of 24 (96%) patients completed at least a 16-week treatment course with buspirone. Sixteen patients (67%; 95% CI 47%, 82%) were treatment responders (CGI-I ≤ 2). Only 1 (4%) patient discontinued buspirone due to a treatment-emergent side effect (nausea and vomiting). The most common side effect was nausea (13%). Twenty (84%) patients remained on buspirone at the time of their most recent follow-up visit. CONCLUSIONS: In this retrospective study, the majority of patients responded to a 16-week course of buspirone. Prospective studies are warranted to further assess the efficacy and tolerability of buspirone for anxiety in WS.

Exposure to the pharmaceutical buspirone alters locomotor activity, anxiety-related behaviors, and transcripts related to serotonin signaling in larval zebrafish (Danio rerio).

Buspirone is a pharmaceutical used to treat general anxiety disorder by acting on the dopaminergic and serotoninergic system. Buspirone, like many human pharmaceuticals, has been detected in municipal wastewater; however, the environmental exposure risks are unknown for this psychoactive compound. We studied the effects of buspirone on the behavior of zebrafish, focusing on locomotor and anxiolytic behavior. We also measured transcripts associated with oxidative stress, neurotoxicity, and serotonin signaling to identify potential mechanisms underlying the behavioral changes. Concentrations ranged from environmentally relevant (nM) to physiologically active concentrations typical of human pharmaceuticals (µM). Buspirone treatment did not impact survival, nor did it induce deformities in zebrafish treated for 7 days up to 10 µM. There was a positive relationship between locomotor activity and buspirone concentration in dark periods of the visual motor response test. In the light-dark preference test, both the average time per visit to the dark zone and the percent cumulative duration in the dark zone were increased by 1 µM buspirone. Transcript levels of ache, manf, and mbp were decreased in larvae, while the expression of gap43 was increased following exposure to buspirone, indicating potential neurotoxic effects. There was also reduced expression of serotonin-related genes encoding receptors, transporters, and biosynthesis enzymes (i.e., 5ht1aa, sertb, and tph1a). These data increase understanding of the behavioral and molecular responses in zebrafish following waterborne exposure to neuroactive pharmaceuticals like buspirone.

Methodological approach: using a within-subjects design in the marble burying assay.

In 2016, the National Institutes of Health mandated the use of both male and female mice in funded research. The use of both sexes is an important variable to consider; however, it comes with negative consequences such as increased animal expenses. One way to combat these negatives is to explore the option of using a within-subjects design (repeated measures) in behavioral assays that historically use a between-subjects design. Our study aimed to determine if a within-subjects design can be utilized in the marble burying assay. The marble burying assay is used as a tool for screening putative anxiolytic compounds as the assay is thought to measure obsessive-compulsive disorder- or anxiety-like behaviors. First, we compared the effects of sex and digging medium (corn cob or Sani Chip) on the number of marbles buried using CD-1 mice. Second, we determined if mice would continue to bury marbles after repeated exposures to the test arena. Lastly, we tested three positive controls (buspirone, ketamine, and fluoxetine). We found that mice buried significantly more marbles within Sani Chip digging medium, and no sex differences were observed. Next, the number of marbles buried and locomotor activity remained consistent across four test sessions. The positive controls buspirone (3.2-10 mg/kg) ketamine (32 mg/kg), and fluoxetine (10 mg/kg) decreased the number of marbles buried using the within-subjects design. These data suggest that a within-subjects design is optimal for the marble burying assay as it will reduce the number of animals and increase statistical power.

A High-Performance Liquid Chromatography with Photodiode Array Detection Method for Simultaneous Determination of Three Compounds Isolated from Wikstroemia ganpi: Assessment of the Effects on Cytochrome P450-Mediated Metabolism In Vitro and In Vivo.

In natural products, the content and quality of the marker components differ depending on the part, production area, collection period, and extraction method; therefore, a standardized analysis method is required to obtain consistent results. This study developed a simultaneous analysis method for three marker components (7-methoxylutolin-5-O-glucoseide, pilloin 5-O-ß-d-glucopyranoside, rutarensin) isolated and purified from Wikstroemia ganpi (W. ganpi). Simultaneous analysis was performed using high-performance liquid chromatography with photodiode array detection (HPLC-PDA) method that was validated according to the International Council for Harmonisation (ICH) guidelines. The developed analytical method exhibited linearity (r2 > 0.999), detection limits (0.72-3.34 µg/mL), and quantification limits (2.19-10.22 µg/mL). The relative standard deviation (RSD) value of intra- and inter-day precisions was less than 1.68%, and analyte recoveries (93.42-117.55%; RSD < 1.86%) were validated according to the analytical procedures, and all parameters were within the allowable range. Quantitative analysis of the three marker components from W. ganpi MeOH extract (WGM) showed 7-methoxylutolin-5-O-glucoseide with the highest content (51.81 mg/g). The inhibitory effects of WGM on cytochrome P450 (CYP) substrate drugs were further investigated. The in vitro study revealed that WGM inhibited the CYP3A-mediated metabolism of buspirone and that 7-methoxylutolin-5-O-glucoseide and pilloin 5-O-ß-d-glucopyranoside inhibited the metabolism of buspirone with IC50 values of 2.73 and 18.7 µM, respectively. However, a single oral dose of WGM did not have significant effects on the pharmacokinetics of buspirone in rats, suggesting that WGM cannot function as an inhibitor of CYP3A-mediated metabolism in vivo.

Incorporation and Performance Verification of Hepatic Portal Blood Flow Shunting in Minimal and Full PBPK Models of Liver Cirrhosis.

Patho-physiological changes in liver cirrhosis create portacaval shunts that allow blood flow to bypass the hepatic portal vein into the systemic circulation affecting drug pharmacokinetics (PKs). The objectives of this work were to implement a physiologically-based pharmacokinetic (PBPK) framework describing shunted blood flows in virtual patients with differing degrees of liver cirrhosis; and to assess the minimal and full PBPK model's performance using drugs with intermediate to high hepatic extraction. Single dose concentration-time profiles and PK parameters for oral ibrutinib, midazolam, propranolol, and buspirone were simulated in healthy volunteers (HVs) and subjects with cirrhosis (Child-Pugh severity score (CP-A, CP-B, or CP-C)). Model performance was verified by comparing predicted to observed fold-changes in PK parameters between HVs and cirrhotic subjects. The verified model was used to simulate the PK changes for simvastatin in patients with cirrhosis. The predicted area under the curve ratios (AUCCirr :AUCHV ) for ibrutinib were 3.38, 6.87, and 11.46 using the minimal PBPK model with shunt and 1.61, 2.58, and 4.33 without the shunt, these compared with observed values of 4.33, 8.14, and 9.04, respectively. For ibrutinib, propranolol, and buspirone, including a shunt in the PBPK model improved the prediction of the AUCCirr :AUCHV and maximum plasma concentration ratios (CmaxCirr :CmaxHV ). For midazolam, an intermediate extraction drug, the differences were less clear. Simulated simvastatin dose adjustments in cirrhosis suggested that 20 mg in CP-A and 10 mg in CP-B could be used clinically. A mechanistic model-informed understanding of the anatomic and pathophysiology of cirrhosis will facilitate improved dose prediction and adjustment in this vulnerable population.

Time-Dependent Effects of Buspirone versus Desipramine on the 5-Choice Serial Reaction Time Task in Rats Reared in Social Isolation: Implication of Early Life Experience and Motoric Impulsivity.

BACKGROUND: Early life social experience and the function of the central serotonin (5-Hydroxytryptophan, 5-HT) system are involved in development of behavioral impulsivity in which individuals act without forethought or before all necessary information is available. However, most of the evidence has been obtained from acute 5-HT manipulation, whereas, the present study aimed to investigate the effects of subchronic regimen targeting of 5-HT1A receptors on motoric waiting impulsivity in socially isolated rats. METHODS: A two-week protocol of buspirone (0.5 mg/kg/day) and desipramine (2.5 mg/kg/day) was employed for rats following social isolation rearing (IR) to examine their behavioral performance in a 5-choice serial reaction time task (5-CSRTT) during the treatment regimen. Responses in any one of the apertures prior to an informative signal were recorded as a premature response. RESULTS: IR rats presented with more locomotor activity than socially reared (SR) rats. Buspirone progressively increased the baseline level of premature responding in a time-dependent manner that was not observed in IR rats. Both IR and SR rats exhibited less premature responding following acute buspirone challenge. For a subchronic desipramine regimen, IR rats followed the same trend of SR controls to increase the prematurity of baseline response. CONCLUSIONS: Buspirone but not desipramine-induced time-dependent effects of motoric waiting impulsivity can be reversed by IR, indicating a role for early life social experience on 5-HT1A receptor-associated ability to control impulsiveness.

Opposing effects of 5-HT1A receptor agonist buspirone on supraspinal abdominal pain transmission in normal and visceral hypersensitive rats.

The serotonergic 5-HT1A receptors are implicated in the central mechanisms of visceral pain, but their role in these processes is controversial. Considering existing evidences for organic inflammation-triggered neuroplastic changes in the brain serotonergic circuitry, the ambiguous contribution of 5-HT1A receptors to supraspinal control of visceral pain in normal and post-inflammatory conditions can be assumed. In this study performed on male Wistar rats, we used microelectrode recording of the caudal ventrolateral medulla (CVLM) neuron responses to colorectal distension (CRD) and electromyography recording of CRD-evoked visceromotor reactions (VMRs) to evaluate post-colitis changes in the effects of 5-HT1A agonist buspirone on supraspinal visceral nociceptive transmission. In rats recovered from trinitrobenzene sulfonic acid colitis, the CRD-induced CVLM neuronal excitation and VMRs were increased compared with those in healthy animals, revealing post-inflammatory intestinal hypersensitivity. Intravenous buspirone (2 and 4 mg/kg) under urethane anesthesia dose-dependently suppressed CVLM excitatory neuron responses to noxious CRD in healthy rats, but caused dose-independent increase in the already enhanced nociceptive activation of CVLM neurons in post-colitis animals, losing also its normally occurring faciliatory effect on CRD-evoked inhibitory medullary neurotransmission and suppressive action on hemodynamic reactions to CRD. In line with this, subcutaneous injection of buspirone (2 mg/kg) in conscious rats, which attenuated CRD-induced VMRs in controls, further increased VMRs in hypersensitive animals. The data obtained indicate a shift from anti- to pronociceptive contribution of 5-HT1A-dependent mechanisms to supraspinal transmission of visceral nociception in intestinal hypersensitivity conditions, arguing for the disutility of buspirone and possibly other 5-HT1A agonists for relieving post-inflammatory abdominal pain.

Buspirone attenuated methotrexate-induced hippocampal toxicity in rats by regulating Nrf2/HO-1, PPAR-γ, NF-κB/nNOS, and ROS/NLRP3/caspase-1 signaling pathways.

Methotrexate (MTX) is a chemotherapeutic agent widely used to treat a variety of tumors. Nonetheless, MTX-induced hippocampal neurotoxicity is a well-defined dose-limiting adverse effect that limits clinical utility. Proinflammatory cytokine production and oxidative stress are possible mechanisms for MTX-induced neurotoxicity. Buspirone (BSP), a partial agonist of the 5-HT1a receptor (5-HT1aR), has emerged as an anxiolytic drug. BSP has been shown to possess antioxidant and anti-inflammatory effects. The current study investigated BSP's potential anti-inflammatory and antioxidant effects in attenuating MTX-induced hippocampal toxicity. Rats received either BSP (1.5 mg/kg) orally for 10 days and MTX (20 mg/kg) i.p. on Day 5. BSP administration markedly protected hippocampal neurons from drastic degenerated neuronal changes induced by MTX. BSP significantly attenuated oxidative injury by downregulating Kelch-like ECH-associated protein 1 expression while potently elevating hippocampal Nrf2, heme oxygenase-1, and peroxisome proliferator-activated receptor expression. BSP dampened inflammation by reducing NO2 - , tumor necrosis factor-alpha, IL-6, and interleukin 1 beta levels mediated by downregulating NF-κB and neuronal nitric oxides synthase expression. Moreover, BSP potently counteracted hippocampal pyroptosis by downregulating NLRP3, ASC, and cleaved-caspase-1 proteins. Therefore, BSP may represent a promising approach to attenuate neurotoxicity in patients receiving MTX.

Serotonergic circuit dysregulation underlying autism-related phenotypes in BTBR mouse model of autism.

The inbred mouse strain, BTBR T+Itpr3tf/J (BTBR), possesses neuronal and circuit abnormalities that underlie atypical behavioral profiles resembling the major symptoms of human autism spectrum disorder (ASD). Forebrain serotonin (5-HT) transmission has been implicated in ASD-related behavioral alterations. In this study, we assessed 5-HT signals and the functional responsiveness in BTBR mice compared to standard C57BL/6J (B6) control mice to elucidate how 5-HT alterations contribute to behavioral abnormalities in BTBR mice. A lower number of 5-HT neurons in the median raphe, but not in the dorsal raphe, was observed in male and female BTBR mice. Acute systemic injection of buspirone, a 5-HT1A receptor agonist, induced c-Fos in several brain regions in both B6 and BTBR mice; however, blunted c-Fos induction in BTBR mice was documented in the cingulate cortex, basolateral amygdala (BLA), and ventral hippocampus (Hipp). Decreased c-Fos responses in these regions are associated with a lack of buspirone effects on anxiety-like behavior in BTBR mice. Analysis of mRNA expression following acute buspirone injection indicated that 5HTR1a gene downregulation (or upregulation) occurred in the BLA and Hipp of B6 mice, respectively, but not BTBR mice. The mRNA expression of factors associated with neurogenesis or the pro-inflammatory state was not consistently altered by acute buspirone injection. Therefore, 5-HT responsivity via 5-HT1A receptors in the BLA and Hipp are linked to anxiety-like behavior, in which circuits are disrupted in BTBR mice. Other distinct 5-HT circuits from the BLA and Hipp that regulate social behavior are restricted but preserved in BTBR mice.

"You can get a couple of ramen noodle packs for a BusparⓇ": A qualitative examination of medication access, policy, and procedures in southern jails.

BACKGROUND: Jails in the United States are required to provide health care to the over 10 million people entering jails each year, a significant portion of whom need medications. Yet little is known about the processes by which medications are prescribed, obtained, and administered to incarcerated persons in jails. OBJECTIVE: To describe medication access, policy, and procedures in jails. METHODS: Semi-structured interviews were conducted with administrators and health workers from 34 jails (of 125 contacted) across 5 states in the southeastern United States. The interview guide covered all aspects of healthcare in jails from entry to release; however, the present study focused on responses relating to medications. Interviews were thematically coded using a combination of deductive and inductive coding guided by the research objective. RESULTS: Four processes described medication use chronologically from intake to release: jail entry and health screening, pharmacy and medication protocols, protocols specific to medication dispensing and administration, and medications at release. Many jails had procedures for using medications brought from home, though some declined to use these medications. Medication decision-making in jails was primarily performed by contracted healthcare providers, and most medications were obtained from contract pharmacies. Almost all jails banned narcotics; however, other medication restrictions varied by jail. Most jails charged a copay for medications. Participants discussed various privacy practices related to medication distribution, as well as approaches to diversion prevention including "crushing and floating" medications. Finally, the pre-release medication management process included transition planning that ranged from no planning to sending additional prescriptions to the patient's pharmacy. CONCLUSIONS: Medication access, protocols, and procedures in jails varies considerably, and there is a need for further adoption of existing standards and guidelines for the use of medications in jails, such as the Assess, Plan, Identify, and Coordinate (APIC) model of community re-entry.

Anxiolytic-like Effects and Quantitative EEG Profile of Palmitone Induces Responses Like Buspirone Rather Than Diazepam as Clinical Drugs.

Anxiety is a mental disorder with a growing worldwide incidence due to the SARS-CoV-2 virus pandemic. Pharmacological therapy includes drugs such as benzodiazepines (BDZs) or azapirones like buspirone (BUSP) or analogs, which unfortunately produce severe adverse effects or no immediate response, respectively. Medicinal plants or their bioactive metabolites are a shared global alternative to treat anxiety. Palmitone is one active compound isolated from Annona species due to its tranquilizing activity. However, its influence on neural activity and possible mechanism of action are unknown. In this study, an electroencephalographic (EEG) spectral power analysis was used to corroborate its depressant activity in comparison with the anxiolytic-like effects of reference drugs such as diazepam (DZP, 1 mg/kg) and BUSP (4 mg/kg) or 8-OH-DPAT (1 mg/kg), alone or in the presence of the GABAA (picrotoxin, PTX, 1 mg/kg) or serotonin 5-HT1A receptor antagonists (WAY100634, WAY, 1 mg/kg). The anxiolytic-like activity was assayed using the behavioral response of mice employing open-field, hole-board, and plus-maze tests. EEG activity was registered in both the frontal and parietal cortex, performing a 10 min baseline and 30 min recording after the treatments. As a result, anxiety-like behavior was significantly decreased in mice administered with palmitone, DZP, BUSP, or 8-OH-DPAT. The effect of palmitone was equivalent to that produced by 5-HT1A receptor agonists but 50% less effective than DZP. The presence of PTX and WAY prevented the anxiolytic-like response of DZP and 8-OH-DPAT, respectively. Whereas only the antagonist of the 5-HT1A receptor (WAY) inhibited the palmitone effects. Palmitone and BUSP exhibited similar changes in the relative power bands after the spectral power analysis. This response was different to the changes induced by DZP. In conclusion, brain electrical activity was associated with the anxiolytic-like effects of palmitone implying a serotoninergic rather than a GABAergic mechanism of action.

Effect of psilocybin on marble burying in ICR mice: role of 5-HT1A receptors and implications for the treatment of obsessive-compulsive disorder.

Preliminary clinical findings, supported by preclinical studies employing behavioral paradigms such as marble burying, suggest that psilocybin may be effective in treating obsessive-compulsive disorder. However, the receptor mechanisms implicated in the putative anti-obsessional effect are not clear. On this background, we set out to explore (1) the role of serotonin 2A (5-HT2A) and serotonin 1A (5-HT1A) receptors in the effect of psilocybin on marble burying; (2) the effect of staggered versus bolus psilocybin administration and persistence of the effect; (3) the effect of the 5-HT1A partial agonist, buspirone, on marble-burying and the head twitch response (HTR) induced by psilocybin, a rodent correlate of psychedelic effects. Male ICR mice were administered psilocybin 4.4 mg/kg, escitalopram 5 mg/kg, 8-hydroxy-2-(di-n-propylamino) tetralin (8-OH-DPAT) 2 mg/kg, M100907 2 mg/kg, buspirone 5 mg/kg, WAY100635 2 mg/kg or combinations, intraperitoneally, and were tested on the marble burying test. HTR was examined in a magnetometer-based assay. The results show that (1) Psilocybin and escitalopram significantly reduced marble burying. The effect of psilocybin was not attenuated by the 5-HT2A antagonist, M100907. The 5-HT1A agonist, 8-OH-DPAT, reduced marble burying as did the 5-HT1A partial agonist, buspirone. The effect of 8-OH-DPAT was additive to that of psilocybin, but that of buspirone was not. The 5-HT1A antagonist, WAY100635, attenuated the effect of 8-OH-DPAT and buspirone but not the effect of psilocybin. (2) Psilocybin injections over 3.5 h had no effect on marble burying and the effect of bolus injection was not persistent. (3) Co-administration of buspirone with psilocybin blocked its effect on HTR. These data suggest that neither 5-HT2A nor 5-HT1A receptors are pivotally implicated in the effect of psilocybin on marble burying. Co-administration with buspirone may block the psychedelic effects of psilocybin without impeding its anti-obsessional effects.

Buspirone for early satiety and symptoms of gastroparesis: A multi-centre, randomised, placebo-controlled, double-masked trial (BESST).

BACKGROUND: Patients with gastroparesis and related disorders have symptoms including early satiety, postprandial fullness and bloating. Buspirone, a 5-HT1 receptor agonist, may improve fundic accommodation. AIM: To determine if buspirone treatment improves early satiety and postprandial fullness in patients with symptoms of gastroparesis. METHODS: This 4-week multi-centre clinical trial randomised patients with symptoms of gastroparesis and moderate-to-severe symptoms of fullness (Gastroparesis Cardinal Symptom Index [GCSI] early satiety/postprandial fullness subscore [ES/PPF]) to buspirone (10 mg orally) or placebo three times per day. The primary outcome was a change in the ES/PPF from baseline to 4 weeks. The primary analysis was per protocol intention-to-treat ANCOVA of between-group baseline vs. 4-week differences (DoD) in ES/PPF adjusted for baseline ES/PPF. Results are reported using both nominal and Bonferroni (BF) p values. RESULTS AND CONCLUSIONS: Ninety-six patients (47 buspirone, 49 placeboes; 92% female, 50% delayed gastric emptying, 39% diabetic) were enrolled. There was no between-groups difference in the 4-week ES/PPF primary outcome: -1.16 ± 1.25 (SD) on buspirone vs -1.03 ± 1.29 (SD) on placebo (mean DoD: -0.11 [95% CI: -0.68, 0.45]; p = 0.69). Buspirone performed better than placebo in patients with severe-to-very severe bloating at baseline compared to patients with none to moderate: (ES/PPF DoD = -0.65 vs. 1.58, pTX*GROUP  = 0.003; pBF  = 0.07). Among individual GCSI symptoms, only bloating appeared to improve with buspirone vs. placebo. CONCLUSIONS: Patients with moderate-to-severe early satiety/postprandial fullness and other symptoms of gastroparesis did not benefit from buspirone treatment to improve the ES/PPF primary outcome compared with placebo. There was a suggestion of the benefit of buspirone in patients with more severe bloating. TRIAL REGISTRATION: ClinicalTrials.gov NCT0358714285.