A retrospective analysis of the "Neverending Trip" after administration of a potent full agonist of 5-HT2A receptor - 25I-NBOMe.

BACKGROUND: 5-HT2A receptor (e.g. 25I-NBOMe) agonists not only pose risks of acute intoxication but also long-term effects and significant adverse reactions, e.g. hallucinogen persisting perception disorder (HPPD), derealization, and depersonalization. AIMS: We evaluated the risk associated with single and repeated use of 25I-NBOMe. We aimed to identify factors that may increase the risk of HPPD, increase its severity and determine the time when the first symptoms appear. Herein, we report the first extensive evaluation of 25I-NBOMe-induced HPPD. METHOD: We assessed all reports (58) collected by The Pomeranian Pharmacovigilance Centre (PPC) from 2013 to 2020. RESULTS: The study included a total of 58 reports of adverse reactions caused by 25I-NBOMe. In the case of 15 reports (in patients aged 19-26 years), symptoms persisted many months after the discontinuation of 25I-NBOMe. The most common were: pseudohallucinations, bizarre delusions, derealizations and in some cases development or worsening of depression has been diagnosed. HPPD-like symptoms were most common in patients who took the drug regularly (i.e., several times a month). The risk of HPPD-like symptoms is higher in patients who have severe visual pseudohallucinations, severe bizarre delusions, derealization and/or depersonalization onset immediately after taking the drug. Recurrence of HPPD symptoms may be provoked by many factors, however, there is some cases there is no apparent reason. HPPD after 25I-NBOMe use can last from 2 months up to 2 years. In some patients, pharmacological treatment was necessary due to 25I-NBOMe-induced HPPD and depression. CONCLUSIONS: The study showed long-lasting effects after 25I-NBOMe administration and allowed for the determination of HPPD risk factors.

Optimal dosing for psilocybin pharmacotherapy: Considering weight-adjusted and fixed dosing approaches.

BACKGROUND: Growing evidence suggests psilocybin, a naturally occurring psychedelic, is a safe and promising pharmacotherapy for treatment of mood and substance use disorders when administered as part of a structured intervention. In most trials to date, psilocybin dose has been administered on a weight-adjusted basis rather than the more convenient procedure of administering a fixed dose. AIMS: The present post hoc analyses sought to determine whether the subjective effects of psilocybin are affected by body weight when psilocybin is administered on a weight-adjusted basis and when psilocybin is administered as a fixed dose. METHODS: We analyzed acute subjective drug effects (mystical, challenging, and intensity) associated with therapeutic outcomes from ten previous studies (total N = 288) in which psilocybin was administered in the range 20 to 30 mg/70 kg (inclusive). Separate multivariate regression analyses examined the relationships between demographic variables including body weight and subjective effects in participants receiving 20 mg/70 kg (n = 120), participants receiving 30 mg/70 kg (n = 182), and participants whose weight-adjusted dose was about 25 mg (to approximate the fixed dose that is currently being evaluated in registration trials for major depressive disorder) (n = 103). RESULTS: In the 20 mg/70 kg and 30 mg/70 kg weight-adjusted groups, and in the fixed dose group, no significant associations were found between subjective effects and demographic variables including body weight or sex. Across a wide range of body weights (49 to 113 kg) the present results showed no evidence that body weight affected subjective effects of psilocybin. CONCLUSIONS: These results suggest that the convenience and lower cost of administering psilocybin as a fixed dose outweigh any potential advantage of weight-adjusted dosing.

Blinded SAPS-PD Assessment After 10 Weeks of Pimavanserin Treatment for Parkinson's Disease Psychosis.

BACKGROUND: Parkinson's disease psychosis (PDP) is a common nonmotor symptom that affects up to 60% of patients. Pimavanserin, a selective 5-HT2A inverse agonist/antagonist, is approved for treating hallucinations and delusions associated with PDP. OBJECTIVE: Evaluate the efficacy and tolerability of pimavanserin in an open-label extension (OLE) study. METHODS: Patients completing a pivotal 6-week placebo-controlled trial (Core Study) could enroll in the OLE. All patients pimavanserin 34 mg once daily, blinded to previous treatment allocation. Prespecified blinded assessments at Week 4 were the Scale for the Assessment of Positive Symptoms (SAPS) PD version and SAPS H + D scales, Caregiver Burden Scale (CBS), and Clinical Global Impression (CGI) Improvement and Severity scales. RESULTS: Of 171 who entered the OLE, 148 (87%) completed Week 4. Among patients who received placebo in the Core Study, mean (SD) change from OLE baseline to OLE Week 4 for the SAPS-PD was - 3.4 (6.3); p < 0.0001. Mean change from Core Study baseline to OLE Week 4 for SAPS-PD was similar among prior pimavanserin- and placebo-treated patients (-6.9 vs. -6.3). Improvement was similar with CGI-I, CGI-S, CBS, and SAPS-H + D in patients previously treated with placebo. Adverse events occurred in 92 (53.8%) patients during the 4-week OLE. CONCLUSION: Improvements at OLE Week 4 from pretreatment baseline were similar with placebo and pimavanserin in the Core Study. The beneficial effects observed with pimavanserin in the 6-week Core Study were maintained for 4 weeks in the blinded OLE, supporting the durability of response with pimavanserin 34 mg for PDP over 10 weeks.

Efficacy of psychedelic treatments on depressive symptoms: A meta-analysis.

BACKGROUND: Psychedelic drugs have shown an efficacy in some psychiatric disorders and have an original mechanism of action with a 5-HT2A agonism. AIM: The aim of this meta-analysis was to assess by a quantitative analysis the putative efficacy of psychedelic drugs on depressive symptoms and to investigate the kinetic of this efficacy. METHODS: We searched the MEDLINE and PsycINFO databases through April 2019, without limits on year of publication. Means and standard deviations were extracted to calculate standardized mean differences (SMD). Scores of depressive symptoms were compared with baseline scores at days 7, 14, and 21; weeks 4-5 and 6-8; and months 3 and 6. RESULTS: Eight studies were included in this meta-analysis. A significant decrease of depressive symptoms was found from day 1 (n = 5 studies; SMD = ‒1.4, 95% confidence interval (CI): ‒2.33 to ‒0.48, p = 0.003) to 6 months (n = 4 studies; SMD = ‒1.07, 95% CI: ‒1.44 to ‒0.7, p < 0.001) after psychedelic sessions. No serious adverse effect was reported in all included studies. A transient increase of the heart rate, blood systolic, and diastolic pressure were found after psychedelics compared with placebo. CONCLUSION: This meta-analysis shows that psychedelic treatments were safe and could contribute to a rapid improvement of depressive symptoms.

Chemistry, Analysis, Pharmacokinetics and Pharmacodynamics Aspects of Lorcaserin, a Selective Serotonin 5-HT2C Receptor Agonist: An Update.

This review refers to the all-inclusive details of Lorcaserin Hydrochloride on comprehensive information about the synthesis, analytical methods, pharmacodynamics, pharmacokinetics, drug interactions and adverse effects. Lorcaserin Hydrochloride is chemically (R)-8-Chloro-1-methyl-2,3,4,5- tetrahydro-1H-3-benzazepine hydrochloride. Lorcaserin HCl is a novel, synthetic, centrally-acting selective serotonin C (5-HT2c) receptor, l agonist, which results in increased satiety and decreased food consumption in patients. Headache, dizziness and nausea are the most common side effects associated with this drug. Lorcaserin HCl has two major metabolites, one conjugated with glucuronide called N-carbamoyl glucuronide which is excreted in urine and the second Lorcaserin N-sulfamate, which is circulated in the blood. Lorcaserin HCl is synthesized using four different schemes of which a six-step method that resulted in 92.3% yield with 99.8% of purity is employed for scale-up production. It is analyzed quantitatively in the plasma and brain tissue matrix of rats by Ultra Performance Liquid chromatographic (UPLC) method using MS-MS (Mass Spectrometric) detection.

Efficacy and safety of lorcaserin in obesity: a systematic review and meta-analysis of randomized controlled trials.

Background: Lorcaserin is a novel, selective 5-hydroxytryptamine 2C serotonin receptor agonist, approved for the treatment of obesity. Several phase 3 randomized controlled trials (RCTs) trials have shown a significant reduction in body weight with lorcaserin.Research design and methods: We systematically searched the database of PubMed, Embase, The Cochrane Library and ClinicalTrials.gov up to 31 July 2019 and retrieved all the studies conducted with lorcaserin for ≥1 year that have explicitly reported the efficacy and safety outcomes versus placebo. Subsequently, we studied the effect of lorcaserin on weight reduction, FDA-defined valvulopathy, depression and suicidal risks in RCTs.Results: The meta-analysis of four RCTs (N = 16,856) demonstrated a significant decrease in body weight (mean ∆ -3.076 Kg; 95% CI, -3.49 to -2.66; P < 0.00001), compared to placebo. No significant difference in FDA-defined valvulopathy (RR 1.20; 95% CI, 0.89 to 1.63; P = 0.24), depression (RR 1.07; 95% CI, 0.80 to 1.43; P = 0.67) or suicidal risk (RR 1.43; 95% CI, 0.96 to 2.15; P = 0.08) has been observed with lorcaserin compared to placebo.Conclusions: Lorcaserin reduces body weight modestly, with no obvious serious adverse side effects. The common adverse events noted with lorcaserin include nausea, dizziness, and transient headache.

Lorcaserin: A review of its preclinical and clinical pharmacology and therapeutic potential.

The selective 5-HT2C receptor agonist lorcaserin, in conjunction with lifestyle modification, was approved by the FDA in 2012 for weight management. It has been marketed in the US as Belviq® since 2013. This article provides a review of the preclinical and clinical pharmacology of lorcaserin, including its pharmacokinetic and safety profiles. Preclinical studies with lorcaserin initially focused on simple measures of food intake and body weight gain, but have now expanded to include studies on its effects on appetitive aspects of feeding behaviour and models of binge-eating. A significant number of studies have also shown that lorcaserin alters behaviours related to drug use and addiction, in rodents and non-human primates. Potential clinically-relevant effects of lorcaserin have also been reported in models of pain and seizure-like activity. Not surprisingly, the majority of clinical work with lorcaserin has focused on its effects on weight gain, and on physiological processes related to energy intake. However, results of clinical trials and experimental laboratory studies involving lorcaserin are now appearing which describe effects on a range of other behaviours and physiological functions. These include smoking cessation, cocaine self-administration, and behavioural and brain responses to food cues. All of this work suggests that lorcaserin may have therapeutic potential for a variety of disorders and conditions beyond obesity. Based on clinical experience, including the outcomes from several, large, well-powered clinical obesity trials at the approved 10mg BID dose both pre and post approval, a priori concerns about cardiac valvulopathy have largely been allayed. However, as with any recently approved first-in-class pharmacotherapy, there may be yet-unknown risks, as well as benefits, associated with use of lorcaserin. Nonetheless, the current safety profile and an expanding post approval safety data base should encourage further experimental laboratory-based and clinical trial-based research with lorcaserin in targeted populations to investigate its full therapeutic potential.

The serotonin-2C agonist Lorcaserin delays intravenous choice and modifies the subjective and cardiovascular effects of cocaine: A randomized, controlled human laboratory study.

BACKGROUND: Lorcaserin is a modestly selective agonist for 2C serotonin receptors (5-HT2CR) approved for weight-loss therapy. This class can attenuate cue-induced responding and drug taking in preclinical studies, but effects in humans have not been reported. METHODS AND PARTICIPANTS: We evaluated effects of single 10 mg doses of lorcaserin on the subjective and reinforcing effects of cocaine, using a randomized, double-blind, within-subject, cross-over design. Male, non-treatment-seeking, regular cocaine users received either single doses of oral placebo (n = 9) or lorcaserin (n = 9), followed by low- or high- doses of intravenous cocaine (0.23 or 0.46 mg/kg-injection). They were then allowed to self-administer the lower dose of cocaine. RESULTS: Cocaine was well tolerated after lorcaserin pretreatment. Oral lorcaserin did not modify the number of cocaine injections self-administered. However, it prolonged the time over which participants made intravenous choices relative to the duration of monetary (cash) decisions. Lorcaserin increased ratings of 'high' and 'stimulated' after low-dose cocaine or vehicle, but decreased craving for cocaine after intravenous vehicle. It also caused small but significant increases in heart rate following noncontingent injections of intravenous placebo or cocaine. When active cocaine was self-administered, lorcaserin decreased heart rate after selection of a monetary choice, but increased it following an intravenous choice. CONCLUSIONS: Combined treatment with cocaine and lorcaserin was safe in a limited number of subjects, but did not diminish cocaine-motivated behavior or drug-induced 'high'. Some positive subjective effects of cocaine were enhanced by lorcaserin, and it delayed intravenous choices and decreased craving under some conditions. Effects on heart rate depended on the type of reinforcer being self-administered. TRIAL REGISTRATION: clinicaltrials.gov Identifier, NCT02680288.

Lorcaserin and Renal Outcomes in Obese and Overweight Patients in the CAMELLIA-TIMI 61 Trial.

BACKGROUND: Obesity is thought to increase renal hyperfiltration, thereby increasing albuminuria and the progression of renal disease. The effect of pharmacologically mediated weight loss on renal outcomes is not well-described. Lorcaserin, a selective serotonin 2C receptor agonist that promotes appetite suppression, led to sustained weight loss without any increased risk for major adverse cardiovascular (CV) events in the CAMELLIA-TIMI 61 trial (Cardiovascular and Metabolic Effects of Lorcaserin in Overweight and Obese Patients-Thrombolysis in Myocardial Infarction 61). METHODS: CAMELLIA-TIMI 61 randomly assigned 12 000 overweight or obese patients with or at high risk for atherosclerotic CV disease to lorcaserin or placebo on a background of lifestyle modification. The primary renal outcome was a composite of new or worsening persistent micro- or macroalbuminuria, new or worsening chronic kidney disease, doubling of serum creatinine, end-stage renal disease, renal transplant, or renal death. RESULTS: At baseline, 23.8% of patients had an estimated glomerular filtration rate (eGFR) <60 mL·min-1·1.73 m-2 and 19.0% had albuminuria (urinary albumin:creatinine ratio ≥30 mg/g). Lorcaserin reduced the risk of the primary renal composite outcome (4.2% per year versus 4.9% per year; hazard ratio [HR], 0.87; 95% confidence interval [CI], 0.79-0.96; P=0.0064). The benefit was consistent across subpopulations at increased baseline CV and renal risk. Lorcaserin improved both eGFR and urinary albumin:creatinune ratio within the first year after randomization. The effect of lorcaserin on weight, hemoglobin A1c, and systolic blood pressure was consistent regardless of baseline renal function. Likewise, there was no excess in cardiovascular events in patients assigned to lorcaserin in comparison with placebo, regardless of renal function. After adjustment for baseline characteristics, those with evidence of kidney disease were at increased risk of major CV events. Compared with patients with an eGFR ≥90 mL·min-1·1.73 m-2, those with an eGFR 60-90 and those <60 mL·min-1·1.73 m-2 had HRs of 1.25 (95% CI, 1.01, 1.56) and 1.51 (95% CI, 1.17, 1.95), respectively ( P for trend 0.0015). Likewise, compared with patients with no albuminuria (<30 mg/g), those microalbuminuria and those with macroalbuminuria had HRs of 1.46 (95% CI, 1.22, 1.74) and 2.10 (95% CI, 1.58, 2.80), respectively ( P for trend <0.0001). CONCLUSIONS: Renal dysfunction was associated with increased CV risk in overweight and obese patients. When added to diet and lifestyle, lorcaserin reduced the rate of new-onset or progressive renal impairment in comparison with placebo. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02019264.

The neuropharmacology of sleep paralysis hallucinations: serotonin 2A activation and a novel therapeutic drug.

Sleep paralysis is a state of involuntary immobility occurring at sleep onset or offset, often accompanied by uncanny "ghost-like" hallucinations and extreme fear reactions. I provide here a neuropharmacological account for these hallucinatory experiences by evoking the role of the serotonin 2A receptor (5-HT2AR). Research has shown that 5-HT2AR activation can induce visual hallucinations, "mystical" subjective states, and out-of-body experiences (OBEs), and modulate fear circuits. Hallucinatory experiences triggered by serotonin-serotonergic ("pseudo") hallucinations, induced by hallucinogenic drugs-tend to be "dream-like" with the experiencer having insight ("meta-awareness") that he is hallucinating, unlike dopaminergic ("psychotic" and "life-like") hallucinations where such insight is lost. Indeed, hallucinatory experiences during sleep paralysis have the classic features of serotonergic hallucinations, and are strikingly similar to perceptual and subjective states induced by hallucinogenic drugs (e.g., lysergic acid diethylamide [LSD] and psilocybin), i.e., they entail visual hallucinations, mystical experiences, OBEs, and extreme fear reactions. I propose a possible mechanism whereby serotonin could be functionally implicated in generating sleep paralysis hallucinations and fear reactions through 5-HT2AR activity. Moreover, I speculate on the role of 5-HT2C receptors vis-à-vis anxiety and panic during sleep paralysis, and the orbitofrontal cortex-rich with 5-HT2A receptors-in influencing visual pathways during sleep paralysis, and, in effect, hallucinations. Finally, I propose, for the first time, a drug to target sleep paralysis hallucinations and fear reactions, namely the selective 5-HT2AR inverse agonist, pimavanserin. This account implicates gene HTR2A on chromosome 13q as the underlying cause of sleep paralysis hallucinations and could be explored using positron emission tomography.

Design and rationale for the Cardiovascular and Metabolic Effects of Lorcaserin in Overweight and Obese Patients-Thrombolysis in Myocardial Infarction 61 (CAMELLIA-TIMI 61) trial.

OBJECTIVES: Lorcaserin, a selective serotonin 2C receptor agonist, is an effective pharmacologic weight-loss therapy that improves several cardiovascular risk factors. The long-term clinical cardiovascular and metabolic safety and efficacy in patients with elevated cardiovascular risk are unknown. RESEARCH DESIGN AND METHODS: CAMELLIA-TIMI 61 (NCT02019264) is a randomized, double-blind, placebo-controlled, multinational clinical trial designed to evaluate the safety and efficacy of lorcaserin with regard to major adverse cardiovascular events and progression to diabetes in overweight or obese patients at high cardiovascular risk. Overweight or obese patients either with established cardiovascular disease or with diabetes and at least 1 other cardiovascular risk factor were randomized in a 1:1 ratio to lorcaserin 10 mg twice daily or matching placebo. The primary safety objective is to assess for noninferiority of lorcaserin for the composite end point of cardiovascular death, myocardial infarction, or stroke (major adverse cardiovascular event [MACE]) (with noninferiority defined as the upper bound of a 1-sided 97.5% CI excluding a hazard ratio of 1.4) compared with placebo assessed at an interim analysis with 460 adjudicated events. The efficacy objectives, assessed at study completion, will evaluate the superiority of lorcaserin for the primary composite end point of cardiovascular death, myocardial infarction, stroke, hospitalization for unstable angina, heart failure, or any coronary revascularization (MACE+) and the key secondary end point of conversion to diabetes. Recruitment began in January 2014 and was completed in November 2015 resulting in a total population of 12,000 patients. The trial is planned to continue until at least 1,401 adjudicated MACE+ events are accrued and the median treatment duration exceeds 2.5 years. CONCLUSION: CAMELLIA-TIMI 61 is investigating the safety and efficacy of lorcaserin for MACEs and conversion to diabetes in overweight or obese patients with established cardiovascular disease or multiple cardiovascular risk factors.

Pimavanserin, a novel antipsychotic for management of Parkinson's disease psychosis.

INTRODUCTION: Parkinson's disease psychosis (PDP) may develop in up to 60% of Parkinson's patients and is associated with increased morbidity and mortality. It also correlates with depression and dementia, and can contribute to caregiver stress and burnout. Pimavanserin is the first FDA approved drug for the treatment of hallucinations and delusions associated with PDP. Areas covered: For this review, a MEDLINE literature search (via PubMed) and information provided by ACADIA Pharmaceuticals were used. This review will discuss the pathophysiology and current management of PDP. In addition, this review will focus on the rationales behind the development of pimavanserin, mechanism of action, pharmacokinetics, pharmacodynamics, and the clinical trials evaluating the efficacy and safety of pimavanserin. Last, the review will address the drug's package insert warning. Expert commentary: Pimavanserin, a 5HT2A receptor inverse agonist, is the first FDA approved drug for the treatment of PDP which has been shown to reduce psychosis in PD through its unique mechanism of action. Pimavanserin, does not worsen PD motor symptoms and has an acceptable safety profile. The development of pimavanserin as an antipsychotic opened a new therapeutic avenue in the treatment of PDP as well as targeting psychosis in other disorders such as Alzheimer's disease.

Pharmacology and Toxicology of N-Benzylphenethylamine ("NBOMe") Hallucinogens.

Serotonergic hallucinogens induce profound changes in perception and cognition. The characteristic effects of hallucinogens are mediated by 5-HT2A receptor activation. One class of hallucinogens are 2,5-dimethoxy-substituted phenethylamines, such as the so-called 2C-X compounds 2,5-dimethoxy-4-bromophenethylamine (2C-B) and 2,5-dimethoxy-4-iodophenethylamine (2C-I). Addition of an N-benzyl group to phenethylamine hallucinogens produces a marked increase in 5-HT2A-binding affinity and hallucinogenic potency. N-benzylphenethylamines ("NBOMes") such as N-(2-methoxybenzyl)-2,5-dimethoxy-4-iodophenethylamine (25I-NBOMe) show subnanomolar affinity for the 5-HT2A receptor and are reportedly highly potent in humans. Several NBOMEs have been available from online vendors since 2010, resulting in numerous cases of toxicity and multiple fatalities. This chapter reviews the structure-activity relationships, behavioral pharmacology, metabolism, and toxicity of members of the NBOMe hallucinogen class. Based on a review of 51 cases of NBOMe toxicity reported in the literature, it appears that rhabdomyolysis is a relatively common complication of severe NBOMe toxicity, an effect that may be linked to NBOMe-induced seizures, hyperthermia, and vasoconstriction.

Safety and tolerability review of lorcaserin in clinical trials.

Lorcaserin is a novel selective serotonin 2C receptor agonist indicated by the US Food and Drug Administration for chronic weight management in adults with obesity or overweight with ≥1 comorbidity. The safety and efficacy of lorcaserin were established during two Phase III clinical trials in patients without diabetes (BLOOM and BLOSSOM) and one Phase III clinical trial in patients with type 2 diabetes (BLOOM-DM). Headache was the most common adverse event experienced by patients during all Phase III trials. Additional adverse events occurring in >5% of patients receiving lorcaserin included dizziness, fatigue, nausea, dry mouth and constipation in patients without diabetes, and hypoglycaemia, back pain, cough and fatigue in patients with diabetes. In a pooled analysis of echocardiographic data collected during the three lorcaserin Phase III trials, the incidence of FDA-defined valvulopathy was similar in patients taking lorcaserin and the placebo. Here, the safety profile of lorcaserin at the FDA-approved dose of 10 mg twice daily is reviewed using data from the lorcaserin Phase III programme, with a focus on theoretical adverse events commonly associated with agonists of the serotonin receptor family. Based on the lorcaserin Phase III clinical trial data, lorcaserin is safe and well tolerated in the indicated patient populations.

Pimavanserin: First Global Approval.

Pimavanserin (Nuplazid™) is a selective and potent serotonin 2A (5-HT2A) receptor inverse agonist and antagonist developed by ACADIA Pharmaceuticals that has been approved in the US as a treatment for patients with hallucinations and delusions associated with Parkinson's disease psychosis. Up to 60 % of patients with Parkinson's disease may develop Parkinson's disease psychosis, which is associated with increased morbidity and mortality and has few treatment options. This article summarizes the milestones in the development of pimavanserin leading to this first approval for the treatment of hallucinations and delusions in patients with Parkinson's disease psychosis.

Ocular Hypotensive Response in Nonhuman Primates of (8R)-1-[(2S)-2-Aminopropyl]-8,9-dihydro-7H-pyrano[2,3-g]indazol-8-ol a Selective 5-HT2 Receptor Agonist.

Recently, it has been reported that 5-HT2 receptor agonists effectively reduce intraocular pressure (IOP) in a nonhuman primate model of glaucoma. Although 1-[(2S)-2-aminopropyl]indazol-6-ol (AL-34662) was shown to have good efficacy in this nonhuman primate model of ocular hypertension as well as a desirable physicochemical and permeability profile, subsequently identified cardiovascular side effects in multiple species precluded further clinical evaluation of this compound. Herein, we report selected structural modifications that resulted in the identification of (8R)-1-[(2S)-2-aminopropyl]-8,9-dihydro-7H-pyrano[2,3-g]indazol-8-ol (13), which displayed an acceptable profile to support advancement for further preclinical evaluation as a candidate for proof-of-concept studies in humans.

Hiccups associated with switching from olanzapine to aripiprazole in a patient with paranoid schizophrenia.

This article reports the case of a 29-year-old schizophrenic woman without somatic illness in whom switching from olanzapine to aripiprazole induced hiccups. Antipsychotics are thought to be effective in the treatment of hiccups; however, they have rarely been reported to induce hiccups. Within 24 hours of taking aripiprazole, the patient began having hiccups continuously. One week after the hiccups ceased, the patient resumed taking aripiprazole, and the hiccups began again. Although rare, this case study suggests that aripiprazole induces hiccups.

Safety Pharmacology assessment of drugs with biased 5-HT(2B) receptor agonism mediating cardiac valvulopathy.

INTRODUCTION: The rhythmic opening and tightly closing of cardiac valve leaflets are cardiac cyclic events imposing to blood a unidirectional course along the vascular tree. Drugs with 5-HT2B agonism properties can seriously compromise this biological function critical for hemodynamic efficiency as their intrinsic pro-fibrotic effects can, with time, make valvular coaptation blood regurgitant. TOPICS COVERED: Cardiac valve anatomy, physiology and pathology as well as 5-HT2B receptor properties (coupling, effects mediated, biased agonism) are briefly exposed. Approaches to unveil 5-HT2B receptor liability of drug candidates are detailed. In silico computational models can rapidly probe molecules for chemical signatures associated with 5-HT2B receptor affinity. In vitro radioligand competition assays allow quantifying receptor binding capacity (Ki, IC50), the pharmacological nature (agonism, antagonism) of which can be ascertained from cytosolic second messenger (inositol phosphates, Ca(++), MAPK2) changes. Potencies calculated from the latter data may exhibit variability as they are dependent upon the readout measured and the experimental conditions (e.g., receptor density level of cell material expressing human 5-HT2B receptors). The in vivo valvulopathy effects of 5-HT2B receptor agonists can be assessed by echocardiographic measurements and valve histology in rats chronically treated with the candidate drug. Finally, safety margins derived from from nonclinical and clinical data are evaluated in terms of the readout, usefulness and scientific reliability. DISCUSSION: The Safety Pharmacology toolbox for detecting possible 5-HT2B receptor agonism liabilities of candidate drugs requires meticulous optimization and validation of all its (in silico, in vitro and in vivo) components to perfect its human predictability power. In particular, since 5-HT2B receptor agonism is biased in nature, the most predictive readout(s) of valvular liability should be identified and prioritized in keeping with best scientific practice teachings.