Effects of MDMA on sociability and neural response to social threat and social reward

Rationale  There has been controversy over the abuse potential of methylphenidate (MPH) in the context of treatment for attention deficit hyperactivity disorder (ADHD). Objective  The objective of this study was to compare the reinforcing and subjective effects of oral MPH in adults with and without ADHD. Materials and methods  Following screening, 33 adults (n = 16 with ADHD; n = 17 free from psychiatric diagnoses) completed four pairs of experimental sessions, each of which included a sampling session and a self-administration session. During sampling sessions, subjects received in randomized order 0 (placebo), 20, 40, and 60 mg MPH. During self-administration sessions, subjects completed a progressive ratio (PR) task to earn portions of the dose received on the corresponding sampling session. Subjective effects were recorded throughout all sessions. The main outcome measure for the study was the number of ratios completed on the PR task. Secondary measures included peak subjective effects and area-under-the-curve values for subjective effects. Results  Compared to the control group, the ADHD group completed more ratios on the PR task. Both groups showed robust effects of methylphenidate on subjective endpoints. Main effects of group were noted on subjective effects involving concentration and arousal. Conclusions  Compared to placebo, MPH produced reinforcing effects only for the ADHD group and not for the control group. Increases in stimulant-related subjective effects in non-ADHD subjects were not associated with drug reinforcement.

Acute tryptophan depletion and self-injurious behavior in aggressive patients and healthy volunteers

Rationale  An association between serotonin (5-HT) activity and self-injurious (i.e., self-aggressive) behavior across the spectrum of lethality (from self-mutilation through completed suicide) is a well-replicated finding. Studies to date, however, have relied on nonexperimental designs to examine this relationship, limiting the causal inferences that can be drawn about the role of 5-HT in self-aggressive behavior. Objective  Examine the effect of experimentally altered 5-HT activity (via dietary tryptophan depletion) on self-aggressive behavior among adults with and without intermittent explosive disorder (IED). Individuals with a marked history of aggression, such as those with IED, are characterized by compromised 5-HT and heightened risk for self-aggression, making this a population of interest for examining the proposed relations. Materials and methods  IED patients (n = 16) and healthy controls (n = 16) received a tryptophan depletion and a placebo drink on separate days at least 1 week apart. Self-aggressive behavior was assessed on both study days using a well-validated laboratory-based behavioral assessment with self-aggression defined as the intensity of shock self-administered. Results  Tryptophan depletion facilitated selection of more intense shocks, on average, in both groups. Patients with IED were also more self-aggressive overall than healthy volunteers. No IED by drink condition interactions were found. Conclusion  Experimentally lowered 5-HT bioavailability enhances overall self-injurious behavior irrespective of aggression history.

Identification of Novel Specific and General Inhibitors of the Three Major Human ATP-Binding Cassette Transporters P-gp,BCRP and MRP2 Among Registered Drugs

Purpose  To study the inhibition patterns of the three major human ABC transporters P-gp (ABCB1), BCRP (ABCG2) and MRP2 (ABCC2), using a dataset of 122 structurally diverse drugs. Methods  Inhibition was investigated in cellular and vesicular systems over-expressing single transporters. Computational models discriminating either single or general inhibitors from non-inhibitors were developed using multivariate statistics. Results  Specific (n = 23) and overlapping (n = 19) inhibitors of the three ABC transporters were identified. GF120918 and Ko143 were verified to specifically inhibit P-gp/BCRP and BCRP in defined concentration intervals, whereas the MRP inhibitor MK571 was revealed to inhibit all three transporters within one log unit of concentration. Virtual docking experiments showed that MK571 binds to the ATP catalytic site, which could contribute to its multi-specific inhibition profile. A computational model predicting general ABC inhibition correctly classified 80% of both ABC transporter inhibitors and non-inhibitors in an external test set. Conclusions  The inhibitor specificities of P-gp, BCRP and MRP2 were shown to be highly overlapping. General ABC inhibitors were more lipophilic and aromatic than specific inhibitors and non-inhibitors. The identified specific inhibitors can be used to delineate transport processes in complex experimental systems, whereas the multi-specific inhibitors are useful in primary ABC transporter screening in drug discovery settings. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Intranasal desmopressin as an adjunct to risperidone for negative symptoms of schizophrenia: A randomized,double-blind,placebo-controlled,clinical trial

Considering the role of neurohypophyseal peptides in normal development and function of higher cortical processes along with their proven abnormalities in schizophrenic patients, these pathways have recently attracted greater attention as treatment targets for schizophrenia. Desmopressin (DDAVP) is a synthetic analog of vasopressin. This study aimed to evaluate the efficacy and safety of DDAVP nasal spray as an adjunct to risperidone in improving negative symptoms of schizophrenia. In this randomized double-blind placebo-controlled clinical trial, forty patients aged 18–50 years with a DSM IV-TR diagnosis of chronic schizophrenia and a minimum score of 60 on positive and negative syndrome scale (PANSS) were equally randomized to receive DDAVP nasal spray (20 mcg/day) or placebo in addition to risperidone for 8 weeks. Patients were partially stabilized and treated with a stable dose of risperidone (5 or 6 mg/day) for at least four weeks prior to entry. Participants were rated by PANSS every two weeks and decrease in the PANSS negative subscale score was considered as our primary outcome. By the study endpoint, DDAVP-treated patients showed significantly greater improvement in the negative symptoms (P=0.001) as well as the PANSS total and general psychopathology subscale scores (P=0.005 and P=0.003; respectively) compared to the placebo group. Treatment group was the strongest predictor of changes in negative symptoms (β=−0.48, t=−3.67, P=001). No serious adverse event or fluid/electrolyte imbalance was reported in this trial. In conclusion, DDAVP nasal spray showed to be an effective and safe medication for improving negative symptoms in patients with chronic schizophrenia.     

Attenuation of the effects of <Emphasis Type="Italic">d</Emphasis>-amphetamine on interval timing behavior by central 5-hydroxytryptamine depletion

Rationale  Interval timing in the free-operant psychophysical procedure is sensitive to the monoamine-releasing agent d-amphetamine, the D₂-like dopamine receptor agonist quinpirole, and the D₁-like agonist 6-chloro-2,3,4,5-tetrahydro-1-phenyl-1H-3-benzepine (SKF-81297). The effect of d-amphetamine can be antagonized by selective D₁-like and 5-HT_2A receptor antagonists. It is not known whether d-amphetamine’s effect requires an intact 5-hydroxytryptamine (5-HT) pathway. Objective  The objective of this study was to examine the effects of d-amphetamine, quinpirole, and SKF-81297 on timing in intact rats and rats whose 5-hydroxytryptaminergic (5-HTergic) pathways had been ablated. Materials and methods  Rats were trained under the free-operant psychophysical procedure to press levers A and B in 50-s trials in which reinforcement was provided intermittently for responding on A in the first half, and B in the second half of the trial. Percent responding on B (%B) was recorded in successive 5-s epochs of the trials; logistic functions were fitted to the data for derivation of timing indices (T ₅₀, time corresponding to %B = 50%; Weber fraction). The effects of d-amphetamine (0.4 mg kg⁻¹ i.p.), quinpirole (0.08 mg kg⁻¹ i.p.), and SKF-81297 (0.4 mg kg⁻¹ s.c.) were compared between intact rats and rats whose 5-HTergic pathways had been destroyed by intra-raphe injection of 5,7-dihydroxytryptamine. Results  Quinpirole and SKF-81297 reduced T ₅₀ in both groups; d-amphetamine reduced T ₅₀ only in the sham-lesioned group. The lesion reduced 5-HT levels by 80%; catecholamine levels were not affected. Conclusions   d-Amphetamine’s effect on performance in the free-operant psychophysical procedure requires an intact 5-HTergic system. 5-HT, possibly acting at 5-HT_2A receptors, may play a ‘permissive’ role in dopamine release.

Vandetanib with docetaxel as second-line treatment for advanced breast cancer: a double-blind, placebo-controlled, randomized Phase II study

Purpose The aim of this Phase II study was to assess the efficacy and safety of vandetanib in combination with docetaxel in patients with pretreated advanced breast cancer. Methods The primary study objective was to compare the number of progression events in patients receiving once-daily oral vandetanib (100 mg) in combination with docetaxel (100 mg/m² iv every 21 days) versus placebo plus docetaxel. Sixty-four patients were randomized to receive study treatment (n = 35, vandetanib; n = 29, placebo). Results A slightly greater number of patients had experienced a progression event by the data cut-off in the vandetanib group (24 [69%]) compared with the placebo group (18 [62%]); HR = 1.19, two-sided 80% CI: 0.79–1.81; two-sided P = 0.59), suggesting that the addition of vandetanib to docetaxel did not affect the risk of disease progression compared with placebo plus docetaxel. The safety and tolerability profile of the combination therapy reflected those of both drugs as monotherapy agents. Conclusions In patients with advanced breast cancer, vandetanib plus docetaxel was generally well tolerated. Clinical benefit was not different to that observed with placebo plus docetaxel. However, due to the small patient number it was not possible to yield robust results, further research is required to identify predictive factors for patient selection.     

Lack of sedative effects after vespertine intake of oxazepam as hypnotic in healthy volunteers

Aims  An objective physiological test was used to investigate the hangover effect, its time course and dose relationship compared to placebo and an herbal relaxant. Methods  Pupillographic Sleepiness Test as an objective measurement, Stanford Sleepiness Scale (SSS) and visual analogue scales (VAS) were used. Study design included: (a) randomised, double-blind, double-dummy, placebo-controlled crossover trial; (b) double-blind, placebo-controlled, randomised study. Primary end point was the Pupillary Unrest Index (lnPUI). Results  Oxazepam 10 mg did not increase PUI. In the VAS and SSS, there was no increase in sleepiness after the three treatment periods. Neither 10 nor 30 mg oxazepam caused sedation in healthy volunteers. Subjective and objective sleepiness measures correlated significantly. Discussion  The lack of sedative effects after vespertine intake of oxazepam (10/30 mg) seems to be relevant with respect to product safety. With regard to the subjective perception at 30 mg, fatigue rather than sleepiness may be the underlying reason.

A randomized,double-blind,placebo-controlled trial to assess prevention of mood episodes with risperidone long-acting injectable in patients with bipolar I disorder

The efficacy and safety of risperidone long-acting injectable (LAI) for preventing recurrence of mood episodes in patients with bipolar I disorder was evaluated in a randomized, placebo-controlled study. After a 12-week open-label period with risperidone LAI (n=560), patients who did not experience a recurrence entered an 18-month randomized, double-blind period with risperidone LAI (n=132) or placebo (n=135); a third treatment arm (n=131) was randomized to oral olanzapine (10 mg/day) for reference and exploratory comparisons. The primary efficacy endpoint was time to recurrence of any mood episode for risperidone LAI versus placebo in the double-blind period (Kaplan–Meier analysis). Additional efficacy endpoints included Young Mania Rating Scale, Montgomery–Asberg Depression Rating Scale and Clinical Global Impression. During the double-blind period, dosing was fixed at patients' final open-label dose (25 mg, 66% of patients; 37.5 mg, 31%; 50 mg, 4%). The primary outcome demonstrated a median time to mood episode recurrence of 198 day in the placebo arm, whereas the median was not reached in the risperidone LAI arm (p=0.057). Time to recurrence of any mood episode was significantly longer with risperidone LAI versus placebo (log-rank test stratified by region only, p=0.031); the difference was significant for time to recurrence of elevated mood episodes (p=0.005) but not depressive episodes (p=0.655). Significant improvement of manic symptoms and global condition versus placebo were observed for risperidone LAI, with no evidence of worsening of depression. In conclusion, risperidone LAI significantly delayed time to recurrence of elevated mood episodes, with a safety profile consistent with previous studies.     

A neurocomputational account of catalepsy sensitization induced by D2 receptor blockade in rats: context dependency,extinction, and renewal

Rationale  Repeated haloperidol treatment in rodents results in a day-to-day intensification of catalepsy (i.e., sensitization). Prior experiments suggest that this sensitization is context-dependent and resistant to extinction training. Objectives  The aim of this study was to provide a neurobiological mechanistic explanation for these findings. Materials and methods  We use a neurocomputational model of the basal ganglia and simulate two alternative models based on the reward prediction error and novelty hypotheses of dopamine function. We also conducted a behavioral rat experiment to adjudicate between these models. Twenty male Sprague–Dawley rats were challenged with 0.25 mg/kg haloperidol across multiple days and were subsequently tested in either a familiar or novel context. Results  Simulation results show that catalepsy sensitization, and its context dependency, can be explained by “NoGo” learning via simulated D2 receptor antagonism in striatopallidal neurons, leading to increasingly slowed response latencies. The model further exhibits a non-extinguishable component of catalepsy sensitization due to latent NoGo representations that are prevented from being expressed, and therefore from being unlearned, during extinction. In the rat experiment, context dependency effects were not dependent on the novelty of the context, ruling out the novelty model’s account of context dependency. Conclusions  Simulations lend insight into potential complex mechanisms leading to context-dependent catalepsy sensitization, extinction, and renewal. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.

Short-term effect of quercetin on the pharmacokinetics of fexofenadine,a substrate of P-glycoprotein,in healthy volunteers

Objective  The aim of the present study was to assess whether quercetin exhibited any inhibitory effect on P-glycoprotein (P-gp)-mediated drug disposition in humans using fexofenadine as a P-gp substrate. Methods  Twelve healthy subjects were enrolled in the study and treated daily for 7 days with 500 mg quercetin or placebo 3 times a day. On day 7, a single dose of 60 mg fexofenadine was administered orally. Plasma and urinary fexofenadine concentrations were measured, and pharmacokinetic differences between placebo and quercetin phases were assessed. Results  The mean plasma concentrations of fexofenadine were significantly increased after quercetin treatment compared to those of the placebo phase. The area under the time versus concentration curve (AUC) of plasma fexofenadine was increased by 55% by quercetin (2,005.3 versus 3,098.6 ng·h/mL, P < 0.001) and similarly the maximum plasma concentration (C_max) during the quercetin phase was elevated by 68% compared to that of the placebo phase (295.3 versus 480.3 ng/mL, P = 0.006). Although the oral clearance of fexofenadine was decreased significantly by 37% after quercetin treatment (61.4 versus 38.7 L/h, P < 0.001), no differences in the renal clearance and half-life were observed between placebo and quercetin phases. Conclusion  The results of the present study showed that short-term use of quercetin elevated the plasma concentrations of fexofenadine, probably by the inhibition of P-gp-mediated efflux in humans.     

Lurasidone in the treatment of schizophrenia: a 6-week, placebo-controlled study

Rationale

There is an unmet need in the treatment of schizophrenia for effective medications with fewer adverse effects.

Objective

This study aims to evaluate the efficacy and safety of lurasidone, an atypical antipsychotic, for the treatment of schizophrenia.

Methods

Patients with an acute exacerbation of schizophrenia were randomized to 6 weeks of double-blind treatment with once-daily, fixed-dose lurasidone 40 mg (N?=?50), lurasidone 120 mg (N?=?49), or placebo (N?=?50). The primary efficacy measure was mean change from baseline to day 42 (last observation carried forward) in the Brief Psychiatric Rating Scale derived (BPRSd) from the Positive and Negative Syndrome Scale (PANSS).

Results

Mean change in BPRSd was significantly greater in patients receiving lurasidone 40 and 120 mg/day versus placebo (?9.4 and ?11.0 versus ?3.8; p?=?0.018 and 0.004, respectively). Treatment with lurasidone 120 mg/day was superior to placebo across all secondary measures, including PANSS total (p?=?0.009), PANSS positive (p?=?0.005), PANSS negative (p?=?0.011), and PANSS general psychopathology (p?=?0.023) subscales and Clinical Global Impression of Severity (CGI-S; p?=?0.001). Treatment with lurasidone 40 mg/day was superior to placebo on the PANSS positive subscale (p?=?0.018) and CGI-S (p?=?0.002). The most common adverse events for patients receiving lurasidone were nausea (16.2 versus 4.0 % for placebo) and sedation (16.2 versus 10.0 % for placebo). Minimal changes in weight, cholesterol, triglyceride, and glucose levels were observed.

Conclusions

In this study, which was limited by a relatively high discontinuation rate, lurasidone provided effective treatment for patients with acute exacerbation of chronic schizophrenia and had minimal effects on weight and metabolic parameters.     

Gender differences in the prevalence,risk and clinical correlates of tardive dyskinesia in Chinese schizophrenia

Objective  Despite extensive use of antipsychotic drug treatment, few studies address the prevalence of tardive dyskinesia (TD) in homogeneous ethnic groups such as the Chinese. This study examined gender-specific relationships between TD and symptom levels in schizophrenia among Han Chinese, which have previously received little systematic study. Materials and methods  Five hundred and twenty-two inpatients with schizophrenia receiving long-term treatment with antipsychotics were evaluated with the AIMS. The patient’s psychopathology was assessed with the Positive and Negative Syndrome Scale (PANSS). Demographic and clinical data were collected from a detailed questionnaire and medical records. Results  The overall TD prevalence was 33.7% with rates of 39.2% (138/352) in males and 22.4% (38/170) in females (χ ² = 14.6, df = 1, p < 0.0001; adjust odds ratio 2.06; CI, 1.32–3.16). The AIMS score in patients with TD was lower in females than males (5.3 ± 3.9 vs 6.7 ± 3.7, t = 2.52, p < 0.01) after adjustment for the significant covariates. TD was associated with the negative symptoms on the PANSS in both genders, and with age, PANSS total and positive symptoms in men, not women. Conclusion  Our present findings suggest that there are gender differences in the prevalence, risk, and clinical correlates of TD in schizophrenia. Although this study is limited by cross-sectional designs, the magnitude of these gender-specific differences is substantial and deservers further prospective study.     

Oral metamizol (1 g and 2 g) versus ibuprofen and placebo in the treatment of lower third molar surgery pain: randomised double-blind multi-centre study

Objective: To assess the efficacy of metamizol 1 g and 2 g in the relief of pain after surgical extraction of the lower third molar, and to compare the therapeutic effect with that of ibuprofen 600 mg or placebo. Methods: A total of 253 patients aged between 18 years and 60 years who had undergone extraction of the lower third molar (types II–IV) under local anaesthesia, up to a maximum of 108 mg of mepivacaine, were randomly assigned to a single oral dose of a new galenic form (drinkable vials) of metamizol 1 g (n = 75), metamizol 2 g (n = 72), ibuprofen 600 mg (n = 74) or placebo (n = 32). Pain intensity was evaluated by a 100-mm visual analogue scale. To enter the study, a pain level of 50 mm or more was required. The duration of the trial was 1 h. Assessments were carried out at 15, 30 and 60 min after treatment. Results: The analgesic efficacy of metamizol 2 g was significantly better than ibuprofen and placebo with regard to all evaluated parameters. The values of the pain intensity difference at 15 min, the percentage of patients with a decrease of 50% or more on the visual analogue scale at 60 min and the sum of pain intensity differences at 60 min showed metamizol 2 g to be significantly more effective than metamizol 1 g. In general, metamizol 1 g was as effective as ibuprofen 600 mg. The analgesic efficacy of placebo was significantly lower than that of all active treatments. A lower number of patients treated with metamizol 1 g (n = 1) or metamizol 2 g (n = 1) needed rescue medication than those given ibuprofen (n = 7) or placebo (n = 5). No serious adverse effects developed and none of the patients had to leave the study for this reason. Conclusions: The model of the lower third molar, for which the analgesic outcome referred to the first hour after drug administration, demonstrated that the analgesic efficacy of oral metamizol 2 g was significantly higher than that of ibuprofen 600 mg or placebo. Metamizol 1 g and ibuprofen 600 mg showed a similar therapeutic effect. All regimens were as well tolerated as placebo. Received: 6 July 1997 / Accepted in revised form: 6 October 1997     

Phase I study of pemetrexed and pegylated liposomal doxorubicin in patients with refractory breast,ovarian, primary peritoneal,or fallopian tube cancer

Purpose: Pemetrexed and pegylated liposomal doxorubicin (PLD) are clinically active as single agents and preclinically synergistic. This phase I, open-label trial evaluated the maximum tolerated dose (MTD) and safety of pemetrexed followed by PLD in patients with breast or gynecologic cancers. Patients: Using 3 + 3 dose escalation, cohorts of 3–9 patients received escalating doses of pemetrexed 400–500 mg/m² on days 1 and 15 and PLD 30–45 mg/m² on day 1 of a 28-day cycle. All patients received folic acid and vitamin B₁₂ until 21 days after last pemetrexed dose. Patients continued until dose-limiting toxicity (DLT) or progression (PD). Results: From 11/05 to 2/08, 29 patients entered treatment; median age: 60.6 years (range, 47.5–80.1); ECOG PS 0/1: 27.6%/72.4%; primary disease site: ovarian (55.2%), breast (34.5%), peritoneum (10.3%); prior therapies: chemotherapy (100.0%), surgery (72.4%), hormones/biologics (35%), and radiation (20.7%). Pemetrexed/PLD dose levels: L1 = 400/30 (n = 4), L2 = 400/35 (n = 6), L3 = 500/35 (n = 9), L4 = 500/40 (n = 7), and L5 = 500/45 (n = 3). Treatment-related grade 3-4 toxicities: hematologic—neutropenia (86.2%), leukopenia (58.6%), thrombocytopenia (48.3%), anemia (41.4%); nonhematologic—mucosal inflammation (24.1%), febrile neutropenia (24.1%), hand-foot syndrome (13.8%), hypokalaemia (10.3%). Reasons for discontinuation: PD (48.3%), toxicity (27.6%), patient request (13.8%), and investigator request (10.3%). Efficacy: 5 ovarian patients (20.8%) achieved partial response; median time to progression (TTP) was 6.1 months (range, 1.2–12.5). Conclusion: Pemetrexed plus PLD was reasonably tolerated in this heavily–pretreated population. MTD: pemetrexed 500 mg/m² and PLD 40 mg/m² may be carried forward to phase II studies in specific patient populations. TTP in platinum-refractory ovarian patients was greater than expected.     

Effects of allicin on CYP2C19 and CYP3A4 activity in healthy volunteers with different <Emphasis Type="Italic">CYP2C19</Emphasis> genotypes

Objective  To investigate the interaction between allicin and omeprazole and to observe the effects of allicin on CYP2C19 and CYP3A4 activity in healthy Chinese male volunteers with different CYP2C19 genotypes. Methods  Eighteen subjects (six CYP2C19*1/CYP2C19*1, four CYP2C19*1/CYP2C19*2, two CYP2C19*1/ CYP2C19*3, and six CYP2C19*2/ CYP2C19*2) were enrolled in a two-phase randomized crossover trial. In each phase, all subjects received placebo or a 180 mg allicin capsule once daily for 14 consecutive days. The pharmacokinetics of omeprazole (20 mg orally on day 15) was determined for up to 12 h following administration by high-performance liquid chromatography. Results  In carriers of the CYP2C19*1/CYP2C19*1 and CYP2C19*1/CYP2C19*2 or *3 genotype, allicin treatment increased the peak plasma concentration (C_max) of omeprazole by 49.7 ± 7.2 (p < 0.001) and 54.2 ± 9.2% (p < 0.001), and increased the area under the plasma time–concentration curve ( ) of omeprazole by 48.1 ± 9.0 (p = 0.001) and 73.6 ± 26.7% (p < 0.001), respectively. The ratio of of 5-hydroxyomeprazole to omeprazole (a marker for CYP2C19 activity) decreased significantly (p < 0.001 and p = 0.001, respectively). However, no pharmacokinetic parameters were significantly changed by allicin in CYP2C19*2/CYP2C19*2. The C_max and of omeprazole sulfone were unchanged in all three genotypes. Conclusions  Allicin reduced the metabolism of omeprazole by inhibiting CYP2C19 activity in individuals with the CYP2C19*1/CYP2C19*1 and CYP2C19*1/CYP2C19*2 or *3 genotypes, but not in those with the CYP2C19*2/ CYP2C19*2 genotype. Allicin did not significantly affect the activity of CYP3A4 in all subjects.     

Effect of varenicline and bupropion SR on craving, nicotine withdrawal symptoms, and rewarding effects of smoking during a quit attempt

Aims To examine the effect of varenicline, a selective alpha4-beta2 nicotinic acetylcholine receptor (nAChR) partial agonist, on craving and withdrawal symptoms in smokers making a quit attempt and the rewarding effects of smoking during a lapse after the target quit date (TQD). Materials and methods Pooled data were analysed from two identical double-blind, randomised trials comparing varenicline 1 mg BID, bupropion (sustained release) 150 mg BID and placebo using measures of craving and withdrawal in the first week after the TQD (in abstinent [n = 612] and non-abstinent participants [n = 1,155]) and of the rewarding effects of the first cigarette smoked in non-abstinent participants. Results In abstinent and non-abstinent participants combined, varenicline reduced craving more than bupropion (p < 0.01) and placebo (p < .001); the effect did not differ by whether or not subjects were abstinent; bupropion reduced craving more than placebo (p < 0.001). Among abstinent participants, both varenicline and bupropion reduced negative affect more than those receiving placebo (p < 0.005). Neither active drug reduced restlessness, insomnia or appetite vs placebo. Varenicline reduced ratings of satisfaction and psychological reward after the first cigarette smoked after the TQD vs bupropion (p < 0.005) and placebo (p < 0.001); bupropion also reduced these more than placebo (p < 0.05). Conclusions Varenicline significantly reduces craving and the rewarding effects of smoking after the TQD to a greater extent than bupropion, which may contribute to varenicline’s greater efficacy for smoking cessation. Varenicline’s lack of effect in reducing insomnia, restlessness and increased appetite in this analysis suggests that receptors other than the alpha4-beta2 nAChR subtype may be implicated in these withdrawal symptoms.     

Mammalian epoxide hydrolases in xenobiotic metabolism and signalling

Epoxide hydrolases catalyse the hydrolysis of electrophilic—and therefore potentially genotoxic—epoxides to the corresponding less reactive vicinal diols, which explains the classification of epoxide hydrolases as typical detoxifying enzymes. The best example is mammalian microsomal epoxide hydrolase (mEH)—an enzyme prone to detoxification—due to a high expression level in the liver, a broad substrate selectivity, as well as inducibility by foreign compounds. The mEH is capable of inactivating a large number of structurally different, highly reactive epoxides and hence is an important part of the enzymatic defence of our organism against adverse effects of foreign compounds. Furthermore, evidence is accumulating that mammalian epoxide hydrolases play physiological roles other than detoxification, particularly through involvement in signalling processes. This certainly holds true for soluble epoxide hydrolase (sEH) whose main function seems to be the turnover of lipid derived epoxides, which are signalling lipids with diverse functions in regulatory processes, such as control of blood pressure, inflammatory processes, cell proliferation and nociception. In recent years, the sEH has attracted attention as a promising target for pharmacological inhibition to treat hypertension and possibly other diseases. Recently, new hitherto uncharacterised epoxide hydrolases could be identified in mammals by genome analysis. The expression pattern and substrate selectivity of these new epoxide hydrolases suggests their participation in signalling processes rather than a role in detoxification. Taken together, epoxide hydrolases (1) play a central role in the detoxification of genotoxic epoxides and (2) have an important function in the regulation of physiological processes by the control of signalling molecules with an epoxide structure.

A randomized,controlled, dose-ranging trial of sertindole in patients with schizophrenia

Sertindole is a novel antipsychotic agent with high selectivity for the mesolimbic dopaminergic pathway and nanomolar affinities for dopamine D₂, serotonin 5-HT₂, and norepinephrine NE₁ receptors. This 40-day randomized, placebo-controlled, dose-ranging multicenter study was designed to assess the effect of sertindole on previously neuroleptic-responsive, hospitalized schizophrenic patients (n=205). Sertindole doses began at 4 mg/day and were increased to 8, 12, or 20 mg/day, depending on randomization. Efficacy measures included the Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS), and Clinical Global Impression (CGI). Extrapyramidal symptoms (EPS) were assessed by movement rating scales, EPS-related adverse events, and use of anti-EPS medications. A dose-related improvement was observed for PANSS, BPRS, and CGI, with statistically significant mean differences (P<0.05) between placebo and 20-mg/day sertindole (decreases from baseline of –5.8 versus –16.9 for PANSS, –4.8 versus –10.4 for BPRS, respectively). The differences in CGI final improvement score between placebo and 20-mg/day sertindole were 3.8 versus 2.9, respectively. EPS-related events were comparable in the placebo and sertindole groups. In conclusion, sertindole 20 mg/day was effective, well tolerated, and not associated with significant motor system abnormalities.This study was presented as a podium presentation at the 23rd Annual Meeting of the American College of Neuropsychopharmacology, Honolulu, Hawaii, December 13–17, 1993. Members of the Sertindole Study Group are listed under Acknowledgements     

Single-dose dextropropoxyphene in post-operative pain: a quantitative systematic review

Objective: To determine the analgesic efficacy and adverse effects of single-dose oral dextropropoxyphene alone and in combination with paracetamol for moderate to severe post-operative pain. Methods: Published reports were identified from a variety of electronic databases including MEDLINE, Biological Abstracts, EMBASE, the Cochrane Library and the Oxford Pain Relief Database. Additional studies were identified from the reference lists of retrieved reports. Summed pain intensity and pain relief data were extracted and converted into dichotomous information to yield the number of patients with at least 50% pain relief. This was used to calculate the relative benefit and number-needed-to-treat for one patient to achieve at least 50% pain relief. Six reports (440 patients) compared dextropropoxyphene with placebo and five (963 patients) compared dextropropoxyphene plus paracetamol 650 mg with placebo. Results: For a single dose of dextropropoxyphene 65 mg in post-operative pain the number-needed-to-treat for at least 50% pain relief was 7.7 (95% confidence interval 4.6 to 22) when compared with placebo over 4–6 h. For the equivalent dose of dextropropoxyphene in combination with paracetamol 650 mg the number-needed-to-treat was 4.4 (3.5 to 5.6) when compared with placebo. Pooled data showed increased incidence of central nervous system adverse effects for dextropropoxyphene plus paracetamol when compared with placebo. A rank order of single-dose analgesic effectiveness in post-operative pain of moderate to severe intensity obtained from similar systematic reviews is presented. Conclusion: Dextropropoxyphene 65 mg plus paracetamol 650 mg has a similar analgesic efficacy to that of tramadol 100 mg but with a lower incidence of adverse effects. Ibuprofen 400 mg has a lower (better) number-needed-to-treat than both dextropropoxyphene 65 mg plus paracetamol 650 mg and tramadol 100 mg. Received: 2 June 1997 / Accepted in revised form: 11 November 1997