Tesofensine

NS-2330 (Neurosearch).

NeuroSearch is developing NS-2330, a compound that increases the activity of dopamine, norepinephrine and acetylcholine, as a potential therapy for Alzheimer's disease (AD) and Parkinson's disease (PD) [260782]. It is in phase II for AD [355341], and by March 2001 was also in a phase II tolerability trial in PD patients with dyskinesia. Phase III studies are expected to begin in the third quarter of 2002 [413151]. At this time, NeuroSearch was in licensing negotiations with a number of companies and had expected an agreement to be concluded within the first half of 2001 [401800]. In June 2001, NeuroSearch decided to continue the in-house development of NS-2330 provided that a capital increase could be effected on satisfactory terms [412065], [413151]. In August 2001, the company confirmed that it had raised these funds and phase III studies were planned for the third quarter of 2002 [420708]. In September 2001, WestLB Panmure predicted that NS-2330 had 12 and 15% probabilities of reaching market for its PD and AD indications, respectively. It also predicted that the drug would be launched in 2008 and 2007 for these indications, with market shares of 12.5 and 25%, respectively [423585].

Tesofensine, a monoamine reuptake inhibitor for the treatment of obesity.

Tesofensine, a monoamine reuptake inhibitor, is under development by NeuroSearch A/S for the potential treatment of obesity. In vitro, the compound potently blocked dopamine, norepinephrine and serotonin reuptake. Initial development, which was conducted by NeuroSearch in collaboration with Boehringer Ingelheim Corp, demonstrated that although tesofensine was ineffective as a treatment for neurodegenerative conditions, a notable occurrence of unintended weight loss was observed in individuals treated with the drug. Preclinical data from diet-induced obese rats supported the hypothesis that tesofensine reduces body weight, and NeuroSearch has since pursued the development of the compound as an oral anti-obesity drug. In phase II clinical trials with tesofensine in obese individuals, dose-related reductions in body weight, body fat and waist circumference, as well as improvements in other obesity-related endocrine factors, were observed. Overall, tesofensine was associated with minor adverse events. Tesofensine caused dose-dependent elevations in heart rate, with significant increases in blood pressure at the highest dose tested. The initial positive findings suggest that tesofensine may be a well-tolerated long-term treatment for obesity, with minimal cardiovascular effects; this view appears to be shared by the FDA, which recently endorsed the phase III trial program for the agent.

Tesofensine, a novel antiobesity drug, silences GABAergic hypothalamic neurons.

Obesity is a major global health epidemic that has adverse effects on both the people affected as well as the cost to society. Several anti-obesity drugs that target GLP-1 receptors have recently come to the market. Here, we describe the effects of tesofensine, a novel anti-obesity drug that acts as a triple monoamine neurotransmitter reuptake inhibitor. Using various techniques, we investigated its effects on weight loss and underlying neuronal mechanisms in mice and rats. These include behavioral tasks, DeepLabCut videotaped analysis, electrophysiological ensemble recordings, optogenetic activation, and chemogenetic silencing of GABAergic neurons in the Lateral Hypothalamus (LH). We found that tesofensine induces a greater weight loss in obese rats than lean rats, while differentially modulating the neuronal ensembles and population activity in LH. In Vgat-ChR2 and Vgat-IRES-cre transgenic mice, we found for the first time that tesofensine inhibited a subset of LH GABAergic neurons, reducing their ability to promote feeding behavior, and chemogenetically silencing them enhanced tesofensine's food-suppressing effects. Unlike phentermine, a dopaminergic appetite suppressant, tesofensine causes few, if any, head-weaving stereotypy at therapeutic doses. Most importantly, we found that tesofensine prolonged the weight loss induced by 5-HTP, a serotonin precursor, and blocked the body weight rebound that often occurs after weight loss. Behavioral studies on rats with the tastant sucrose indicated that tesofensine's appetite suppressant effects are independent of taste aversion and do not directly affect the perception of sweetness or palatability of sucrose. In summary, our data provide new insights into the effects of tesofensine on weight loss and the underlying neuronal mechanisms, suggesting that tesofensine may be an effective treatment for obesity and that it may be a valuable adjunct to other appetite suppressants to prevent body weight rebound.

Population pharmacokinetic modelling of NS2330 (tesofensine) and its major metabolite in patients with Alzheimer's disease.

To develop a population pharmacokinetic model for NS2330 and its major metabolite M1 based on data from a 14 week proof of concept study in patients with Alzheimer's disease, and to identify covariates that might influence the pharmacokinetic characteristics of the drug and/or its metabolite. Plasma data from 320 subjects undergoing multiple oral dosing, and consisting of 1969 NS2330 and 1714 metabolite concentrations were fitted simultaneously using NONMEM. Plasma concentration-time profiles of NS2330 and M1 were best described by one-compartment models with first-order elimination for both compounds. Absorption of NS2330 was best modelled by a first-order process. Low apparent clearances together with large apparent volumes of distribution resulted in long half-lives of 234 h (NS2330) and 374 h (M1). The covariate analysis identified weight, sex, CL(CR), BMI and age as influencing the pharmacokinetics of NS2330 and/or M1. However, simulations performed revealed that only CL(CR) and sex had a significant effect on the steady-state plasma concentration-time profiles. Females with a creatinine clearance of 35.6 ml min(-1) showed a 62% increased exposure compared with males without renal impairment. The robustness and accuracy of the model were demonstrated by the successful predictivity of an external dataset. A descriptive, robust and predictive model for NS2330 and its M1 metabolite was developed. Important covariates influencing pharmacokinetics were identified, which might guide the further development of NS2330 and optimize its long-term use in the treatment of Alzheimer's disease.

Structural basis for pharmacotherapeutic action of triple reuptake inhibitors.

Most first-line pharmacotherapeutic strategies for depression aim to boost serotonin and norepinephrine levels. However, 35% of patients with depression do not respond adequately to these treatments or experience adverse side effects. The serotonin-norepinephrine-dopamine reuptake inhibitors, also known as triple reuptake inhibitors (TRIs), are emerging as promising antidepressants with greater potency and fewer side effects. Here, we determine an ensemble of structures of DAT in complex with five distinct TRIs. Tesofensine and dasotraline stabilize DAT in an outward-facing conformation, while centanafadine, ansofaxine, and nefazodone capture the inward-facing conformation. These structures reveal binding poses and interactions involved in the association of inhibitors. Notably, ansofaxine binds at a location which is much closer to the intracellular membrane surface. Through extensive structural analysis, we establish a comprehensive blueprint for the association of these TRIs, which is crucial for future drug development aimed at achieving potent antidepressant with fewer side effect.

Tesofensine and weight loss.

Tesofensine and weight loss.

Weight loss produced by tesofensine in patients with Parkinson's or Alzheimer's disease.

Tesofensine (TE) is a norepinephrine, dopamine, and serotonin reuptake inhibitor. We conducted a meta-analysis of TE's effect on body weight in trials investigating its potential for treatment of Parkinson's or Alzheimer's disease. Four randomized, double-blind, multicenter trials compared TE (n = 740) and placebo (n = 228), two in each disease. Patients received oral TE or placebo once daily for 14 weeks without any weight loss program. Results were adjusted for baseline values, age, and study. In the placebo group, 14% were obese and 21% were in the TE group. In the total cohort, weight change after 14 weeks was +0.5, -0.5, -0.9, -1.8, -2.8% in the placebo, 0.125, 0.25, 0.5 and 1.0 mg in the TE groups, respectively (P = 0.015 for dose effect). In the obese subgroup, weight changes were -0.2, -1.7, -1.6, -1.5, -3.7%, and 2.1, 8.2, 14.1, 20.9, 32.1% of the obese patients achieved > or = 5% weight loss (P < 0.001 for 0.25, 0.5, and 1.0 mg vs. placebo for both end points). Changes in heart rate were -0.4, 2.1, 4.2, 6.0, and 6.8 bpm after 14 weeks (TE vs. placebo: P < 0.001 from 0.25 mg), but no effect on blood pressure was observed. TE produced a placebo-subtracted weight loss of approximately 4% for >14 weeks without any diet and lifestyle therapy, which is similar to that of sibutramine, but with no effect on blood pressure. On the basis of these results, TE is now being developed for obesity management.

Semi-mechanistic population pharmacokinetic drug-drug interaction modelling of a long half-life substrate and itraconazole.

For compounds with a long elimination half-life, the evaluation of a drug-drug interaction (DDI) study can be challenging. The standard analytical approach of a non-compartmental analysis (NCA) might not be able to detect the full interaction potential and may lead to a significant underestimation of the interaction. The most appropriate method for data analysis might be a semi-mechanistic population pharmacokinetic modelling approach. To accomplish a semi-mechanistic DDI model for a long-elimination-half-life drug substrate, tesofensine, and the cytochrome P450 (CYP) 3A4 inhibitor itraconazole, and to compare the results of the semi-mechanistic model with the results obtained from the standard NCA approach. Additionally, the impact of different schedules of itraconazole on tesofensine pharmacokinetics and the general performance of the standard NCA approach were evaluated. Overall, 28 subjects received a single oral dose of tesofensine 2 mg; 14 of these subjects were coadministered an oral itraconazole 400 mg loading dose and a 200 mg maintenance dose for 6 days before and 5 days after administration of tesofensine. The dataset contained 465 plasma concentrations of tesofensine (full profiles) and 80 plasma concentrations of itraconazole (trough values). First, pharmacokinetic models of itraconazole and tesofensine were developed in parallel. Subsequently, a combined model was developed, taking into account CYP3A4 inhibition. The analyses were performed using NONMEM software. The plasma concentration-time profiles of itraconazole and tesofensine were best described by a one-compartment model for each drug, with first-order elimination rate constants that were both inhibited by itraconazole concentrations. Inhibition resulted in reduced clearances and prolonged elimination half-lives for tesofensine and itraconazole: using NCA, the actual study revealed an approximately 9% increase in exposure for the timeframe of the coadministration with itraconazole (the area under the plasma concentration-time curve (AUC) from 0 to 144 hours [AUC(144h)]), and the impact on exposure estimated to infinity (AUC(infinity)) was approximately 26%. These results are in contrast to the model-predicted results, where the inhibitory effect of itraconazole caused a 38% reduction in the clearance of tesofensine, leading to a 63% increased exposure. This analysis presents a semi-mechanistic population pharmacokinetic approach that may be useful for the evaluation of DDI studies. The model can be an aid in evaluating DDI studies for compounds with a long elimination half-life, especially when the inhibitor cannot be administered over a sufficient period. Additionally, the population model-based approach may allow simplification of the design and the analysis and interpretation of safety and efficacy findings in DDI studies.

New and emerging drug molecules against obesity.

Obesity has become a growing pandemic of alarming proportions in the developed and developing countries over the last few decades. The most perturbing fact regarding obesity is the increased predisposition for coronary artery disease, congestive heart failure and sudden cardiac death. The modest efficacy of current anti-obesity agents such as orlistat and the increasing withdrawals of several anti-obesity agents such as sibutramine, rimonabant have led to huge gaps in the pharmacotherapy of obesity. Lorcaserin and Phentermine-topiramate combination (phen-top) are two drugs approved by US FDA in 2012. Lorcaserin, a 5HT2C agonist has moderate efficacy with an acceptable safety profile. Clinical trials with Phen-top have shown a reasonable efficacy but at the cost of risks such as teratogenicity and psychiatric disturbances. Cetilistat, a lipase inhibitor is claimed to have superior safety profile to orlistat and is in phase 3 clinical trials. Other promising anti-obesity molecules acting on the gut which are in clinical trials include exenatide and liraglutide. Drugs which act on the monoaminergic and opioid systems include bupropion-naltrexone and bupropion-zonisamide. Other novel first-in-class drugs which have been explored and have limited success in early clinical development include velneperit, tesofensine, and beloranib. Tesofensine is a triple monoamine re-uptake inhibitor, velneperit acts as a neuropeptide Y5 receptor antagonist and beloranib is a methionine amino peptidase 2 inhibitor. Novel targets such as histamine H3 receptor, VEGF, matrix-metalloproteinase, sirtuin receptors are also being investigated. This review is an attempt to describe the new and emerging molecules that are in clinical development for obesity.

Subjective and objective effects of the novel triple reuptake inhibitor tesofensine in recreational stimulant users.

Tesofensine is a (triple) reuptake inhibitor of noradrenaline, dopamine, and serotonin that is in development for the treatment of obesity. The abuse potential of triple reuptake inhibitors is not yet known, and so this study was undertaken to evaluate the potential abuse-related effects of tesofensine in humans. It was designed as a single-dose, randomized, double-blind, crossover study involving tesofensine vs. placebo, D-amphetamine (positive control for dopaminergic/stimulant effects), bupropion, and atomoxetine (negative/unscheduled controls) in recreational stimulant users (N = 52). Subjective and objective measures were assessed for 48 h after drug administration. The study results show that the effects of D-amphetamine were significantly greater than those of placebo on all primary and secondary subjective measures. The effects of tesofensine were not significantly different from those of placebo and were lower than those of D-amphetamine 30 mg on all primary and most secondary measures. The effects of tesofensine were either lower than or not different from those of bupropion or atomoxetine. These results demonstrate that the abuse potential for tesofensine is no greater than that of bupropion or atomoxetine, and tesofensine is therefore unlikely to be recreationally abused.

Expression of concern--effect of tesofensine on bodyweight loss, body composition, and quality of life in obese patients: a randomised, double-blind, placebo-controlled trial.

Under-reporting of adverse effects of tesofensine.

Tesofensine, a novel triple monoamine reuptake inhibitor, induces appetite suppression by indirect stimulation of alpha1 adrenoceptor and dopamine D1 receptor pathways in the diet-induced obese rat.

Tesofensine is a novel monoamine reuptake inhibitor that inhibits both norepinephrine, 5-HT, and dopamine (DA) reuptake function. Tesofensine is currently in clinical development for the treatment of obesity, however, the pharmacological basis for its strong effect in obesity management is not clarified. Using a rat model of diet-induced obesity (DIO), we characterized the pharmacological mechanisms underlying the appetite suppressive effect of tesofensine. DIO rats treated with tesofensine (2.0 mg/kg, s.c.) for 16 days showed significantly lower body weights than vehicle-treated DIO rats, being reflected by a marked hypophagic response. Using an automatized food intake monitoring system during a 12 h nocturnal test period, tesofensine-induced hypophagia was investigated further by studying the acute interaction of a variety of monoamine receptor antagonists with tesofensine-induced hypophagia in the DIO rat. Tesofensine (0.5-3.0 mg/kg, s.c.) induced a dose-dependent and marked decline in food intake with an ED(50) of 1.3 mg/kg. The hypophagic response of tesofensine (1.5 mg/kg, s.c.) was almost completely reversed by co-administration of prazosin (1.0 mg/kg, alpha(1) adrenoceptor antagonist) and partially antagonized by co-administration of SCH23390 (0.03 mg/kg, DA D(1) receptor antagonist). In contrast, tesofensine-induced hypophagia was not affected by RX821002 (0.3 mg/kg, alpha(2) adrenoceptor antagonist), haloperidol (0.03 mg/kg, D(2) receptor antagonist), NGB2904 (0.1 mg/kg, D(3) receptor antagonist), or ritanserin (0.03 mg/kg, 5-HT(2A/C) receptor antagonist). Hence, the mechanism underlying the suppression of feeding by tesofensine in the obese rat is dependent on the drug's ability to indirectly stimulate alpha(1) adrenoceptor and DA D(1) receptor function.

Effect of tesofensine on bodyweight loss, body composition, and quality of life in obese patients: a randomised, double-blind, placebo-controlled trial.

Weight-loss drugs produce an additional mean weight loss of only 3-5 kg above that of diet and placebo over 6 months, and more effective pharmacotherapy of obesity is needed. We assessed the efficacy and safety of tesofensine-an inhibitor of the presynaptic uptake of noradrenaline, dopamine, and serotonin-in patients with obesity. We undertook a phase II, randomised, double-blind, placebo-controlled trial in five Danish obesity management centres. After a 2 week run-in phase, 203 obese patients (body-mass index 30-</=40 kg/m(2)) were prescribed an energy restricted diet and randomly assigned with a list of randomisation numbers to treatment with tesofensine 0.25 mg (n=52), 0.5 mg (n=50), or 1.0 mg (n=49), or placebo (n=52) once daily for 24 weeks. The primary outcome was percentage change in bodyweight. Analysis was by modified intention to treat (all randomised patients with measurement after at least one dose of study drug or placebo). The study is registered with ClinicalTrials.gov, number NCT00394667. 161 (79%) participants completed the study. After 24 weeks, the mean weight loss produced by diet and placebo was 2.0% (SE 0.60). Tesofensine 0.25 mg, 0.5 mg, and 1.0 mg and diet induced a mean weight loss of 4.5% (0.87), 9.2% (0.91), and 10.6% (0.84), respectively, greater than diet and placebo (p<0.0001). The most common adverse events caused by tesofensine were dry mouth, nausea, constipation, hard stools, diarrhoea, and insomnia. After 24 weeks, tesofensine 0.25 mg and 0.5 mg showed no significant increases in systolic or diastolic blood pressure compared with placebo, whereas heart rate was increased by 7.4 beats per min in the tesofensine 0.5 mg group (p=0.0001). Our results suggest that tesofensine 0.5 mg might have the potential to produce a weight loss twice that of currently approved drugs. However, these findings of efficacy and safety need confirmation in phase III trials.

The effect of tesofensine on appetite sensations.

Tesofensine (TE), an inhibitor of monoamine presynaptic reuptake, has produced twice the weight loss seen with currently marketed drugs. However, its long term effect on appetite in humans has not been studied. A multicentre phase II trial was divided into two parts (24 weeks each). Part 1 had a randomized, double-blind, placebo-controlled design and Part 2, an open-labeled, single-group, uncontrolled design. A drug-free period (12 &#xb1; 3 weeks) separated them. In Part 1, participants (n = 158) were assigned to 0.25, 0.5 or 1.0&#xa0;mg TE, or placebo. Completers of Part 1 were invited to participate in Part 2 (n = 113), during which they all received 0.5 or 1.0&#xa0;mg TE. Appetite sensations and a composite satiety score (CSS = satiety + fullness + (100 - hunger) + (100 - prospective food consumption) were assessed. In Part 1 TE induced a dose-dependent increase in CSS at week 12 that correlated with weight loss during the 24 weeks (r = 0.36, P < 0.0001). However, CSS diminished over time as weight loss progressed (e.g., for 1.0&#xa0;mg; 52 &#xb1; 17&#xa0;mm; 64 &#xb1; 13&#xa0;mm; 55 &#xb1; 13&#xa0;mm at baseline, week 12 and week 24, respectively). After drug withdrawal CSS returned to baseline values (50 &#xb1; 17&#xa0;mm, in the whole sample.), despite the participants' reduced-weight state (-7.2 &#xb1; 6.7&#xa0;kg, P < 0.0001). The reintroduction of TE in Part 2 increased CSS again (56 &#xb1; 17&#xa0;mm at week 60), regardless of initial treatment/weight loss. We postulate that enhanced satiety is involved in early weight loss. Whether the attenuated effect on appetite seen after 24 weeks is due to a counteracting effect in the weight reduced state or whether the appetite suppressing effect of TE per se diminishes over time is, however, still unclear.

Tesofensine--a novel potent weight loss medicine. Evaluation of: Astrup A, Breum L, Jensen TJ, Kroustrup JP, Larsen TM. Effect of tesofensine on bodyweight loss, body composition, and quality of life in obese patients: a randomised, double-blind, placebo-controlled trial. Lancet 2008;372:1906-13.

The incidence of obesity is increasing; this is of major concern, as obesity is associated with cardiovascular disease, stroke, type 2 diabetes, respiratory tract disease, and cancer. This evaluation is of a Phase II clinical trial with tesofensine in obese subjects. After 26 weeks, tesofensine caused a significant weight loss, and may have a higher maximal ability to reduce weight than the presently available anti-obesity agents. However, tesofensine also increased blood pressure and heart rate, and may increase psychiatric disorders. It is encouraging that tesofensine 0.5 mg may cause almost double the weight loss observed with sibutramine or rimonabant. As tesofensine and sibutramine have similar pharmacological profiles, it would be of interest to compare the weight loss with tesofensine in a head-to-head clinical trial with sibutramine, to properly assess their comparative potency. Also, as teso fensine 0.5 mg increases heart rate, as well as increasing the incidence of adverse effects such as nausea, drug mouth, flatulence, insomnia, and depressed mode, its tolerability needs to be further evaluated in large Phase III clinical trials.

Randomized controlled trial of Tesomet for weight loss in hypothalamic obesity.

Hypothalamic injury often leads to rapid, intractable weight gain causing hypothalamic obesity, which is associated with increased risk of cardiovascular and metabolic morbidity and mortality. There are no approved or effective pharmacological treatments for hypothalamic obesity, and conventional lifestyle management remains ineffective. To investigate the safety and efficacy of Tesomet (0.5 mg tesofensine/50 mg metoprolol) in adults with hypothalamic obesity. Twenty-one adults with hypothalamic obesity (16 females) were randomized to Tesomet (0.5 mg/50 mg) or placebo for 24 weeks. Patients also received diet/lifestyle counselling. The primary endpoint was safety; secondary endpoints included measures of body weight, appetite scores, quality of life, and metabolic profile. Eighteen patients completed 24 weeks. Consent withdrawal, eligibility, and serious adverse events (SAE) unrelated to treatment resulted in dropouts. One patient experienced a Tesomet-related SAE of exacerbated pre-existing anxiety leading to treatment discontinuation. Tesomet-related adverse events were otherwise mostly mild and included sleep disturbances (Tesomet 50%, placebo 13%), dry mouth (Tesomet 43%, placebo 0%), and headache (Tesomet 36%, placebo 0%). No significant differences in heart rate or blood pressure were observed between groups. Compared to placebo, Tesomet resulted in additional mean (95% CI) weight change of -6.3% ((-11.3; -1.3); P = 0.017), increased the number of patients achieving &#x2265;5% weight loss (Tesomet 8/13, placebo 1/8; P = 0.046), and tended to augment the reduction in waist circumference by 5.7 cm ((-0.1; 11.5); P = 0.054). Tesomet was welltolerated, did not affect heart rate or blood pressure, and resulted in significant reductions in body weight compared to placebo in adults with hypothalamic obesity.

Anti-hypertensive treatment preserves appetite suppression while preventing cardiovascular adverse effects of tesofensine in rats.

Tesofensine is a novel triple monoamine reuptake inhibitor which is in development for the treatment of obesity. Preclinical and clinical data suggest that appetite suppression is an important mechanism by which tesofensine exerts its robust weight reducing effect. Notably, the strong hypophagic response to tesofensine treatment is demonstrated to be linked to central stimulation of noradrenergic and dopaminergic neurotransmission. The sympathomimetic mode of action of tesofensine may also associate with the elevated heart rate and blood pressure observed in clinical settings, and we therefore sought experimentally to address this issue. The anorexigenic and cardiovascular effects of tesofensine were studied simultaneously in telemetrized conscious rats in a combined real-time food intake and cardiovascular telemetry monitoring system. Acute administration of tesofensine caused a dose-dependent hypophagic effect as well as increased heart rate and blood pressure. Interestingly, combined treatment with metoprolol (b1 adrenoceptor blocker, 10-20 mg/kg, p.o.) fully prevented the cardiovascular sympathetic effects of tesofensine while leaving the robust inhibitory efficacy on food intake unaffected. Similarly, the angiotensin AT1 receptor antagonist telmisartan (1.0-3.0 mg/kg, p.o.) did not interfere with the anti-obesity effects of tesofensine, however, telmisartan only partially reversed the increase in systolic blood pressure and had no effect on the elevated heart rate induced by tesofensine. These data suggests that tesofensine causes elevations in heart rate and blood pressure by increasing sympathetic activity, and that different adrenoceptor subtypes may be responsible for the anti-obesity and cardiovascular effects of tesofensine.

The novel triple monoamine reuptake inhibitor tesofensine induces sustained weight loss and improves glycemic control in the diet-induced obese rat: comparison to sibutramine and rimonabant.

Tesofensine, a novel triple monoamine reuptake inhibitor, produces a significant weight loss in humans. The present study aimed at characterizing the weight-reducing effects of tesofensine in a rat model of diet-induced obesity. Sibutramine and rimonabant were used as reference comparators. Compared to baseline, long-term treatment with tesofensine (28 days, 1.0 or 2.5mg/kg, p.o.) resulted in a significant, dose-dependent and sustained weight loss of 5.7 and 9.9%, respectively. Sibutramine (7.5mg/kg, p.o.) treatment caused a sustained weight loss of 7.6%, whereas the employed dose of rimonabant (10mg/kg, p.o.) only produced a transient weight reduction. While all compounds exhibited a significant inhibitory effect on food intake which gradually wore off, the hypophagic effect of tesofensine was longer lasting than sibutramine and rimonabant. In contrast to tesofensine, the body weight of pair-fed rats returned to baseline at the end of the study, which may indicate that tesofensine stimulated energy expenditure. The differential efficacy on weight reduction was also reflected in lowered body fat depots, as tesofensine and sibutramine most efficiently reduced abdominal and subcutaneous fat mass which was paralleled by reduced plasma lipid levels. In an oral glucose tolerance test, only tesofensine significantly suppressed the plasma insulin response below the level that could be obtained by paired feeding, indicating that tesofensine further improved glycemic control. In conclusion, the robust weight loss with long-term tesofensine treatment is likely due to a combined synergistic effect of appetite suppression and increased energy expenditure.

A quantitative enterohepatic circulation model: development and evaluation with tesofensine and meloxicam.

Drugs undergoing enterohepatic circulation (EHC) are associated with typical pharmacokinetic characteristics such as multiple-peak phenomenon in the plasma concentration-time profile and prolongation of the apparent elimination half-life (t((1/2))). Currently, versatile pharmacokinetic models are lacking that could test the hypothesis of an EHC for observed multiple-peak phenomenon in pharmacokinetic profiles and its quantitative contribution. The aim of this analysis was to accomplish a model that is able to describe typical plasma concentration-time profiles of compounds undergoing EHC using data from intravenous studies of tesofensine and meloxicam. In addition, the developed model should be able to quantify the contribution of an EHC to the pharmacokinetics by determining the influence of interrupting the EHC of tesofensine and meloxicam to various extents. Two studies were investigated retrospectively for model development and model evaluation. Twenty-one healthy subjects received a single 6-hour infusion of tesofensine (0.3, 0.6, 0.9, 1.2 mg) in a double-blind, randomized, placebo-controlled, single rising-dose study. Twelve healthy subjects were treated in a randomized, crossover study with meloxicam 30 mg as a single dose given intravenously (bolus) either alone or concomitantly with cholestyramine. The EHC model was developed based on data from the tesofensine study, where EHC is suspected. Model evaluation was performed with data from the meloxicam trial. Modelling and simulation analyses were performed using the software programs NONMEM, SAS and Berkeley Madonna. Plasma concentration-time profiles of tesofensine were best described by a three-compartment model (absorption, central and gallbladder) with first-order elimination. The release of the bile compartment was controlled by a sine function model, switching the bile compartment periodically on and off using the actual clock time as the control element. A four-compartment model (absorption, central, peripheral and gallbladder) with first-order elimination and the sine function for gallbladder control described the meloxicam data best. Coadministration of cholestyramine resulted in a predicted 56% withdrawal of meloxicam from the EHC process causing a reduction in the t((1/2)) from approximately 19 hours to approximately 12 hours. A quantitative EHC model was successfully developed that was capable of describing the multiple peaks in plasma concentration-time profiles of tesofensine and meloxicam very well. Additionally, the model successfully quantified the observed results for an interruption of the meloxicam EHC. The model offers an in silico method to support an EHC hypothesis using standard pharmacokinetic data and might help to guide dosing recommendations of compounds undergoing EHC.

Tesofensine induces appetite suppression and weight loss with reversal of low forebrain dopamine levels in the diet-induced obese rat.

Tesofensine is a triple monoamine reuptake inhibitor which inhibits noradrenaline, 5-HT and dopamine reuptake. Tesofensine is currently in clinical development for the treatment of obesity, however, the pharmacological basis for its strong and sustained effects in obesity management is not clarified. Tesofensine effectively induces appetite suppression in the diet-induced obese (DIO) rat partially being ascribed to an indirect stimulation of central dopamine receptor function subsequent to blocked dopamine transporter activity. This is interesting, as obese patients have reduced central dopaminergic activity thought to provide a drive for compensatory overeating, but whether treatment with an uptake inhibitor counteracts these changes or not has not been investigated. Tesofensine treatment (2.0 mg/kg/day for 14 days) caused a pronounced anorexigenic and weight-reducing response in DIO rats as compared to age-matched chow-fed rats. DIO rats also exhibited a marked reduction in baseline extracellular dopamine levels in the nucleus accumbens (NAcc) and prefrontal cortex (PFC), as compared to chow-fed rats using microdialysis. While acute administration of tesofensine (2.0 mg/kg) normalized accumbal dopamine levels in DIO rats, the drug had no effect on dopamine levels in chow-fed rats. Tesofensine evoked a stronger stimulatory response on NAcc and PFC dopamine levels in DIO rats, and also induced discrete changes in striatal dopamine D2 receptor expression and transporter binding. In conclusion, tesofensine produces weight loss together with reversal of lowered forebrain dopamine levels in DIO rats, suggesting that tesofensine's anti-obesity effects, at least in part, are associated with positive modulation of central dopaminergic activity.

Triple monoamine inhibitor tesofensine decreases food intake, body weight, and striatal dopamine D2/D3 receptor availability in diet-induced obese rats.

The novel triple monoamine inhibitor tesofensine blocks dopamine, serotonin and norepinephrine re-uptake and is a promising candidate for the treatment of obesity. Obesity is associated with lower striatal dopamine D2 receptor availability, which may be related to disturbed regulation of food intake. This study assesses the effects of chronic tesofensine treatment on food intake and body weight in association with changes in striatal dopamine D2/D3 receptor (D2/3R) availability of diet-induced obese (DIO) rats. Four groups of 15 DIO rats were randomized to one of the following treatments for 28 days: 1. tesofensine (2.0 mg/kg), 2. vehicle, 3. vehicle+restricted diet isocaloric to caloric intake of group 1, and 4. tesofensine (2.0 mg/kg)+ a treatment-free period of 28 days. Caloric intake and weight gain decreased significantly more in the tesofensine-treated rats compared to vehicle-treated rats, which confirms previous findings. After treatment discontinuation, caloric intake and body weight gain gradually increased again. Tesofensine-treated rats showed significantly lower D2/3R availability in nucleus accumbens and dorsal striatum than both vehicle-treated rats and vehicle-treated rats on restricted isocaloric diet. No correlations were observed between food intake or body weight and D2/3R availability. Thus, chronic tesofensine treatment leads to decreased food intake and weight gain. However, this appears not to be directly related to the decreased striatal D2/3R availability, which is mainly a pharmacological effect.

Contribution of the active metabolite M1 to the pharmacological activity of tesofensine in vivo: a pharmacokinetic-pharmacodynamic modelling approach.

Tesofensine is a centrally acting drug under clinical development for Alzheimer's disease, Parkinson's disease and obesity. In vitro, the major metabolite of tesofensine (M1) displayed a slightly higher activity, which however has not been determined in vivo. The aims of this investigation were (i) to simultaneously accomplish a thorough characterization of the pharmacokinetic (PK) properties of tesofensine and M1 in mice and (ii) to evaluate the potency (pharmacodynamics, PD) and concentration-time course of the active metabolite M1 relative to tesofensine and their impact in vivo using the PK/PD modelling approach. Parent compound, metabolite and vehicle were separately administered intravenously and orally over a wide dose range (0.3-20 mg kg(-1)) to 228 mice. Concentrations of tesofensine and M1 were measured; inhibition of the dopamine transporter was determined by co-administration of [(3)H]WIN35,428 as the pharmacodynamic measure. Pharmacokinetics of tesofensine and M1 were best described by one-compartment models for both compounds. Nonlinear elimination and metabolism kinetics were observed with increasing dose. The PK/PD relationship was described by an extended E(max) model. Effect compartments were used to resolve observed hysteresis. EC(50) values of M1, as an inhibitor of the dopamine transporter, were 4-5-fold higher than those for tesofensine in mice. The lower potency of M1 together with approximately 8-fold higher through steady-state concentrations suggest that M1 did contribute to the overall activity of tesofensine in mice.

Safety of antiobesity drugs.

Obesity is a major health problem worldwide. Although diet and physical activity are crucial in the management of obesity, the long-term success rate is low. Therefore antiobesity drugs are of great interest, especially when lifestyle modification has failed. As obesity is not an immediate life-threatening disease, these drugs are required to be safe. Antiobesity drugs that have been developed so far have limited efficacies and considerable adverse effects affecting tolerability and safety. Therefore, most antiobesity drugs have been withdrawn. Fenfluramine and dexfenfluramine were withdrawn because of the potential damage to heart valves. Sibutramine was associated with an increase in major adverse cardiovascular events in the Sibutramine Cardiovascular Outcomes (SCOUT) trial and it was withdrawn from the market in 2010. Rimonabant was withdrawn because of significant psychiatric adverse effects. Orlistat was approved in Europe and the United States for long-term treatment of obesity, but many patients cannot tolerate its gastrointestinal side effects. Phentermine and diethylpropion can only be used for less than 12 weeks because the long-term safety of these drugs is unknown. Ephedrine and caffeine are natural substances but the effects on weight reduction are modest. As a result there is a huge unmet need for effective and safe antiobesity drugs. Recently lorcaserin and topiramate plus phentermine have been approved for the treatment of obesity but long-term safety data are lacking.

Tesofensine (NS 2330), a monoamine reuptake inhibitor, in patients with advanced Parkinson disease and motor fluctuations: the ADVANS Study.

To assess the safety and efficacy of tesofensine, a triple monoamine reuptake inhibitor, in patients with advanced Parkinson disease (PD). A pilot phase 2, randomized, double-blind, placebo-controlled, parallel-group trial. The study occurred in hospital-based outpatient clinics and in clinical trial units. Patients with advanced PD and levodopa-related motor fluctuations were enrolled. Tesofensine (0.125, 0.25, 0.5, or 1 mg) or placebo tablets were administered once daily for 14 weeks. Coprimary end points were the changes from baseline in Unified Parkinson Disease Rating Scale (UPDRS) subscale II (activities of daily living) plus subscale III (motor function) total score and in percentage of waking hours spent in "off" time noted in self-scoring diaries. Secondary end points were safety, pharmacokinetics, responder analysis (> or =20% reduction in UPDRS score and in off time), and changes in percentage of waking hours spent in "on" time with and without troublesome dyskinesia. The adjusted mean differences (relative to placebo) were -4.7 points in UPDRS subscale II plus subscale III total score (P =.005) with tesofensine, 0.5 mg, and -7.1% in off time (-68 minutes, P =.02) with tesofensine, 0.25 mg. Other dosages did not induce statistically significant effects. The plasma concentration increased with the dosage, but no clear dose-response relationship was observed. Gastrointestinal tract and neuropsychiatric adverse events were more frequent with tesofensine than with placebo, especially at the higher dosages. Patients with PD in advanced stages showed modest improvements in UPDRS subscale II plus subscale III total score and in off time when treated with tesofensine, but a dose-response relationship could not be established for efficacy, while adverse drug reactions tended to be more frequent at higher dosages. clinicaltrials.gov Identifier: NCT00148512.

Approaches for the Development of Drugs for Treatment of Obesity and Metabolic Syndrome.

Obesity and metabolic syndrome (MS) are risk factors for diabetes, cancer, some cardiovascular and musculoskeletal diseases. Pharmacotherapy should be used when the body mass index (BMI) exceeds 30 kg/m&#xb2; or 27 kg/m&#xb2; with comorbidity. Efficacy and safety of pharmacotherapy depend on the mechanism of action of drugs. In this context, drugs affecting the central and peripheral mediator systems such as cannabinoid receptor antagonists (Rimonabant), neuronal reuptake inhibitor of NE and 5 HT (Sibutramine), neuronal reuptake inhibitor of NE 5-HT DA (Tesofensine), agonist of 5 HT 2C receptors (Lorcaserin) have a high risk of side effects on the central nervous and cardiovascular systems when used for a long period. Apparently, the drugs design targeting obesity should screen safer drugs that affect fat absorption (Orlistat), activate energy metabolism (Adipokines), inhibit MetAP2 (Beloranib) and other peripheral metabolic processes. The use of synergies of anti-obesity drugs with different mechanisms of action is an effective approach for developing new combined pharmaceutical compositions (Contrave&#xae;, EmpaticTM, Qsymia et al). The purpose of this article is to review the currently available anti-obesity drugs and some new promising trends in development of anti-obesity therapy.

[The effect of tesofensine on body weight and body composition in obese subjects--secondary publication].

Results from a phase II trial with Tesofensine for treatment of obesity are presented. In total 203 obese persons were randomised to treatment with Tesofensine 0.25, 0.5, or 1.0 mg, or placebo daily for 24 weeks. Treatment with Tesofensine resulted in a mean weight reduction of 4.5, 9.2 and 10.6% higher than that of placebo for 0.25, 0.5 and 1.0 mg, respectively. Tesofensine 0.5 mg might have the potential to produce a weight loss twice that of currently approved anti-obesity drugs. Findings of safety and efficacy of 0.5 mg Tesofensine need confirmation in phase III trials.

Expression of brain derived neurotrophic factor, activity-regulated cytoskeleton protein mRNA, and enhancement of adult hippocampal neurogenesis in rats after sub-chronic and chronic treatment with the triple monoamine re-uptake inhibitor tesofensine.

The changes of gene expression resulting from long-term exposure to monoamine antidepressant drugs in experimental animals are key to understanding the mechanisms of action of this class of drugs in man. Many of these genes and their products are either relevant biomarkers or directly involved in structural changes that are perhaps necessary for the antidepressant effect. Tesofensine is a novel triple monoamine reuptake inhibitor that acts to increase noradrenaline, serotonin, and dopamine neurotransmission. This study was undertaken to examine the effect of sub-chronic (5 days) and chronic (14 days) administration of Tesofensine on the expression of brain derived neurotrophic factor (BDNF) and activity-regulated cytoskeleton protein (Arc) in the rat hippocampus. Furthermore, hippocampi from the same animals were used to investigate the effect on cell proliferation by means of Ki-67- and NeuroD-immunoreactivity. We find that chronic, but not sub-chronic treatment with Tesofensine increases BDNF mRNA in the CA3 region of the hippocampus (35%), and Arc mRNA in the CA1 of the hippocampus (65%). Furthermore, the number of Ki-67- and neuroD-positive cells increased after chronic, but not sub-chronic treatment. This study shows that Tesofensine enhances hippocampal gene expression and new cell formation indicative for an antidepressant potential of this novel drug substance.

Pharmacological management of appetite expression in obesity.

For obese individuals, successful weight loss and maintenance are notoriously difficult. Traditional drug development fails to exploit knowledge of the psychological factors that crucially influence appetite, concentrating instead on restrictive criteria of intake and weight reduction, allied to a mechanistic view of energy regulation. Drugs are under development that may produce beneficial changes in appetite expression in the obese. These currently include glucagon-like peptide-1 analogs such as liraglutide, an amylin analog davalintide, the 5-HT(2C) receptor agonist lorcaserin, the monoamine re-uptake inhibitor tesofensine, and a number of combination therapies such as pramlintide and metreleptin, bupropion and naltrexone, phentermine and topiramate, and bupropion and zonisamide. However, the effects of these treatments on eating behavior remain poorly characterized. Obesity is typically a consequence of overconsumption driven by an individual's natural sensitivity to food stimuli and the pleasure derived from eating. Intuitively, these processes should be effective targets for pharmacotherapy, and behavioral analysis can identify drugs that selectively affect desire to eat, enjoyment of eating, satiation or postmeal satiety. Rational interventions designed specifically to modulate these processes could limit the normally aversive consequences of caloric restriction and maximize an individual's capacity to successfully gain control over their appetite.

New approaches to the pharmacological treatment of obesity: can they break through the efficacy barrier?

In this review we assess the range of centrally active anorectics that are either in human clinical trials, or are likely to be so in the near future. We describe their weight loss efficacy, mode of action at both pharmacological and behavioural levels, where understood, together with the range of side effects that might be expected in clinical use. We have however evaluated these compounds against the considerably more rigorous criteria that are now being used by the Federal Drugs Agency and European Medicines Agency to decide approvals and market withdrawals. Several trends are evident. Recent advances in the understanding of energy balance control have resulted in the exploitation of a number of new targets, some of which have yielded promising data in clinical trials for weight loss. A second major trend is derived from the hypothesis that improved weight loss efficacy over current therapy is most likely to emerge from treatments targeting multiple mechanisms of energy balance control. This reasoning has led to the development of a number of new treatments for obesity where multiple mechanisms are targeted, either by a single molecule, such as tesofensine, or through drug combinations such as qnexa, contrave, empatic, and pramlintide+metreleptin. Many of these approaches also utilise advances in formulation technology to widen safety margins. Finally, the practicality of peptide therapies for obesity has become better validated in recent studies and this may allow more rapid exploitation of novel targets, rather than awaiting the development of orally available small molecules. We conclude that novel, more efficacious and better tolerated treatments for obesity may become available in the near future.

Gateways to clinical trials.

Gateways to Clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from the Clinical Trials Knowledge Area of Prous Science Integrity, the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: AAV1/SERCA2a, Abacavir sulfate/lamivudine, Adalimumab, Aliskiren fumarate, Ambrisentan, Aripiprazole, AT-7519, Atazanavir sulfate, Atomoxetine hydrochloride, Azacitidine, Azelnidipine; Besifloxacin hydrochloride, Bevacizumab, Bioabsorbable everolimus-eluting coronary stent, Bortezomib, Bosentan, Budesonide/formoterol fumarate; CAIV-T, Carisbamate, Casopitant mesylate, Certolizumab pegol, Cetuximab, Ciclesonide, Ciprofloxacin/dexamethasone, CTCE-9908; Dalcetrapib, Darunavir, Deferasirox, Desloratadine, Disitertide, Drotrecogin alfa (activated), DTA-H19, Duloxetine hydrochloride, Dutasteride; Ecogramostim, Efalizumab, Emtricitabine, Eribulin mesilate, Escitalopram oxalate, Eszopiclone, EUR-1008, Everolimus-eluting coronary stent, Exenatide; Fampridine, Fluticasone furoate, Formoterol fumarate/fluticasone propionate, Fosamprenavir calcium, Fulvestrant; Gabapentin enacarbil, GS-7904L; HPV-6/11/16/18, Human Secretin, Hydralazine hydrochloride/isosorbide dinitrate; Imatinib mesylate, Imexon, Inalimarev/Falimarev, Indacaterol, Indacaterol maleate, Inhalable human insulin, Insulin detemir, Insulin glargine, Ixabepilone; L-Alanosine, Lapatinib ditosylate, Lenalidomide, Levocetirizine dihydrochloride, Liraglutide, Lisdexamfetamine mesilate, Lopinavir, Loratadine/montelukast sodium, Lutropin alfa; MeNZB, Mepolizumab, Micafungin sodium, Morphine hydrochloride; Nabiximols, Nikkomycin Z; Olmesartan medoxomil, Omalizumab; Paclitaxel-eluting stent, Pegfilgrastim, Peginterferon alfa-2a, Peginterferon alfa-2b, Perifosine, PF-489791, Plitidepsin, Posaconazole, Pregabalin; QAX-576; Raltegravir potassium, Ramelteon, Rasagiline mesilate, Recombinant human relaxin H2, rhGAD65, Rivaroxaban, Rosuvastatin calcium, Rotigotine; Saxagliptin, SCH-530348, Sirolimus-eluting stent, SLIT-amikacin, Sorafenib, Sotrastaurin, SR-16234, Sulforaphane; Tadalafil, Tanespimycin, Tapentadol hydrochloride, Teriparatide, Tesofensine, Tiotropium bromide, Tipifarnib, Tirapazamine, TMC-207, Tocilizumab, Tolvaptan, Tosedostat, Treprostinil sodium; Ustekinumab; Varespladib methyl, Vicriviroc, Vildagliptin, Vildagliptin/metformin hydrochloride, Volociximab, Voriconazole; Ziconotide, Ziprasidone hydrochloride.

Anti-obesity drugs: a review about their effects and their safety.

Amphetamines, rimonabant and sibutramine licenses as anti-obesity drugs have been withdrawn because of their adverse effects. In fact, orlistat is the only available long-term treatment for obesity. The efficacy and safety of long-term drug therapy is very important in the management obesity; for this reason, the authors decided to conduct a review on the efficacy and safety of current, past and future pharmacotherapies for weight loss. Orlistat is a good choice for the treatment of obesity, because of its safety on cardiovascular events and its positive effects on diabetic control, even if it is not as effective as rimonabant or sibutramine in reducing body weight. Regarding emerging anti-obesity therapies in diabetic people, we currently have drugs that have already been marketed including the glucagon-like peptide-1 (GLP-1) receptor agonists exenatide and liraglutide; other than improving glycemic control, they also suppress appetite reducing body weight. Moreover, some other drugs are currently in study such as tesofensine, phentermine + topiramate, bupropion + naltrexone and bupropion + zonisamide. Furthermore, several additional gut hormone-based treatments for obesity are under investigation in Phase II and III clinical trials, with particular focus on ghrelin, peptide YY, pancreatic polypeptide, amylin and oxyntomodulin.

Centrally Acting Agents for Obesity: Past, Present, and Future.

For many years, obesity was believed to be a condition of overeating that could be resolved through counseling and short-term drug treatment. Obesity was not recognized as a chronic disease until 1985 by the scientific community, and 2013 by the medical community. Pharmacotherapy for obesity has advanced remarkably since the first class of drugs, amphetamines, were approved for short-term use. Most amphetamines were removed from the obesity market due to adverse events and potential for addiction, and it became apparent that obesity pharmacotherapies were needed that could safely be administered over the long term. This review of central nervous system (CNS) acting anti-obesity drugs evaluates current therapies such as phentermine/topiramate, which act through multiple neurotransmitter pathways to reduce appetite. In the synergistic mechanism of bupropion/naltrexone, naltrexone blocks the feed-back inhibitory circuit of bupropion to give greater weight loss. Lorcaserin, a selective agonist of a serotonin receptor that regulates food intake, and the glucagon-like-peptide-1 (GLP-1) receptor agonist liraglutide are reviewed. Future drugs include tesofensine, a potent triple reuptake inhibitor in Phase III trials for obesity, and semaglutide, an oral GLP-1 analog approved for diabetes and currently in trials for obesity. Another potential new pharmacotherapy, setmelanotide, is a melanocortin-4 receptor agonist, which is still in an early stage of development. As our understanding of the communication between the CNS, gut, adipose tissue, and other organs evolves, it is anticipated that obesity drug development will move toward new centrally acting combinations and then to drugs acting on peripheral target tissues.

The many different faces of major depression: it is time for personalized medicine.

First line antidepressants are the so-called SSRIs (selective serotonin reuptake inhibitors), e.g. fluvoxamine, fluoxetine, sertraline, paroxetine and escitalopram. Unfortunately, these drugs mostly do not provide full symptom relief and have a slow onset of action. Therefore other antidepressants are also being prescribed that inhibit the reuptake of norepinephrine (e.g. reboxetine, desipramine) or the reuptake of both serotonin (5-HT) and norepinephrine (e.g. venlafaxine, duloxetine, milnacipran). Nevertheless, many patients encounter residual symptoms such as impaired pleasure, impaired motivation, and lack of energy. It is hypothesized that an impaired brain reward system may underlie these residual symptoms. In agreement, there is some evidence that reuptake inhibitors of both norepinephrine and dopamine (e.g. methylphenidate, bupropion, nomifensine) affect these residual symptoms. In the pipeline are new drugs that block all three monoamine transporters for the reuptake of 5-HT, norepinephrine and dopamine, the so-called triple reuptake inhibitors (TRI). The working mechanisms of the above-mentioned antidepressants are discussed, and it is speculated whether depressed patients with different symptoms, sometimes even opposite ones due to atypical or melancholic features, can be matched with the different drug treatments available. In other words, is personalized medicine for major depression an option in the near future?

Anorectic state of obesity medications in the United States. Are leaner times ahead?

Introduction: Obesity is considered to be a chronic disease. Currently there are five prescription-only medications on the US market for the long-term management of obesity. However, these medications are underutilized by obese or overweight individuals seeking medical assistance for weight management.Areas covered: This special report provides an overview of the emerging obesity pharmacotherapies based on the data available from recruiting and active phase II/III trials from a registry of clinical trials. The authors also give their expert opinion and provide their future perspectives on the treatment of obesity based on what is known.Expert opinion: Despite obesity being a chronic condition affecting 40% of the US population, there is a low demand for obesity medications in the US market. Although the potential obesity medications that are currently being investigated in phase II/III clinical trials are promising, it is unclear whether the future pharmacotherapies will be enough to meet the health care need.

Investigations Into the Metabolism and Elimination of Tesofensine in Human Urine.

Tesofensine (NS-2330) is a pharmacologically active compound with weight-reducing effects in obese patients. Although still under regulatory review, it has been marketed online as a dietary supplement promoted for weight management and metabolic enhancement. Due to its impact on body weight, tesofensine could be relevant in competitive sports, particularly in weight-class disciplines and sports where power-to-weight ratio is decisive. It is classified under "S6 stimulants" on the World Anti-Doping Agency's Prohibited List and is prohibited in-competition only, making detailed knowledge of its metabolism and excretion essential for anti-doping purposes. Although the pharmacological effects and elimination of tesofensine and one dealkylated metabolite were described previously, elimination profiles and structural information on additional metabolites have been limited. In this study, in&#xa0;vitro metabolism experiments were conducted, followed by investigation of urinary metabolism and elimination in six volunteers after ingestion of 483&#x2009;&#x3bc;g tesofensine as a dietary supplement. Urine was collected for up to 600&#x2009;h, prepared by solid-phase extraction, and analyzed by LC-HRMS. Four principal metabolites were identified: three dealkylated metabolites (M1-M3) and one hydroxylated and glucuronidated metabolite (M4), supported by MS/MS dissociation patterns. The validated analytical method for human urine showed an LOD of 0.01&#x2009;ng/mL, 34% recovery, and 8% interday imprecision. Marked interindividual variability was observed, with peak concentrations of 1-4&#x2009;ng/mL after 4-46&#x2009;h and detection windows up to 500&#x2009;h. The findings enhance analytical procedures and suggest that recommended dosing is unlikely to result in concentrations constituting an Adverse Analytical Finding (AAF) under currently applicable stimulant minimum reporting levels.

Dopamine reuptake transporter (DAT) "inverse agonism"--a novel hypothesis to explain the enigmatic pharmacology of cocaine.

The long held view is cocaine's pharmacological effects are mediated by monoamine reuptake inhibition. However, drugs with rapid brain penetration like sibutramine, bupropion, mazindol and tesofensine, which are equal to or more potent than cocaine as dopamine reuptake inhibitors, produce no discernable subjective effects such as drug "highs" or euphoria in drug-experienced human volunteers. Moreover they are dysphoric and aversive when given at high doses. In vivo experiments in animals demonstrate that cocaine's monoaminergic pharmacology is profoundly different from that of other prescribed monoamine reuptake inhibitors, with the exception of methylphenidate. These findings led us to conclude that the highly unusual stimulant profile of cocaine and related compounds, eg methylphenidate, is not mediated by monoamine reuptake inhibition alone. We describe the experimental findings which suggest cocaine serves as a negative allosteric modulator to alter the function of the dopamine reuptake transporter (DAT) and reverse its direction of transport. This results in a firing-dependent, retro-transport of dopamine into the synaptic cleft. The proposed mechanism of cocaine is, therefore, different from other small molecule negative allostereric modulators of the monoamine reuptake transporters, eg SoRI-6238, which merely reduce the rate of inward transport. Because the physiological role of DAT is to remove dopamine from the synapse and the action of cocaine is the opposite of this, we have postulated that cocaine's effect is analogous to an inverse agonist. If this hypothesis is validated then cocaine is the prototypical compound that exemplifies a new class of monoaminergic drugs; DAT "inverse agonists". This article is part of the Special Issue entitled 'CNS Stimulants'.

[Recent progress and novel perspectives on obesity pharmacotherapy].

Obesity prevalence has risen dramatically over the past decades, which poses a great number of patients at risk of metabolic and cardiovascular complications. Long-term efficacy of lifestyle modification isolated has shown to be modest which, therefore, urges the need of more aggressive interventions such as adjuvant pharmacotherapy or the more radical surgical approach. Bariatric surgery has proven to date to be the most effective treatment, although it may be associated with nutritional and metabolic complications not yet completely recognized. By contrast, there is limited availability of antiobesity agents currently in the market, as well as historical facts involving the suspension of previously existing medications due to safety concerns. This article aims to present recent data on clinical trials of novel weight-loss drugs with short perspective to enter the market, if approved by the regulatory agencies. This review will discuss the efficacy and safety of these compounds, which include lorcaserin (selective serotonin 5-HT2c agonist), tesofensine (triple monoamine reuptake inhibitor), liraglutide (GLP-1 analogue) and cetilistat (gastrointestinal lipase inhibitor), as well as the combination therapies of bupropion/naltrexone, bupropion/zonisamide, phentermine/topiramate and pramlintide/metreleptin.

Neuropsychiatric adverse effects of centrally acting antiobesity drugs.

Central neurochemical systems including the monoamine, opioid, and cannabinoid systems have been promising targets for antiobesity drugs that modify behavioral components of obesity. In addition to modulating eating behavior, centrally acting antiobesity drugs are also likely to alter emotional behavior and cognitive function due to the high expression of receptors for the neurochemical systems targeted by these drugs within the fronto-striatal and limbic circuitry. This paper reviewed the neuropsychiatric adverse effects of past and current antiobesity drugs, with a central mechanism of action, linking the adverse effects to their underlying neural substrates and neurochemistry. Antiobesity drugs were found to have varying neuropsychiatric adverse event profiles. Insomnia was the most common adverse effect with drugs targeting monoamine systems (sibutramine, bupropion and tesofensine). These drugs had some positive effects on mood and anxiety and may have added therapeutic benefits in obese patients with comorbid depression and anxiety symptoms. Sedation and tiredness were the most common adverse effects reported with drugs targeting the m-opioid receptors (i.e., naltrexone) and combination therapies targeting the opioid and monoamine systems (i.e., Contrave&#x2122;). Cognitive impairments were most frequently associated with the antiepileptic drugs, topiramate and zonisamide, consistent with their sedative properties. Drugs targeting the cannabinoid system (rimonabant and taranabant) were consistently associated with symptoms of anxiety and depression, including reports of suicidal ideation. Similar adverse events have also been noted for the D&#x2081;/D&#x2085; antagonist ecopipam. These findings highlight the need to assess neuropsychiatric adverse events comprehensively using sensitive and validated methods early in the clinical development of candidate antiobesity drugs with a central mechanism of action.