David Feifel

Adjunctive Intranasal Oxytocin Reduces Symptoms in Schizophrenia Patients

BACKGROUND Both human and animal studies suggest oxytocin may have antipsychotic properties. Therefore, we conducted a clinical trial to directly test this notion. METHODS Nineteen schizophrenia patients with residual symptoms despite being on a stable dose of at least one antipsychotic were enrolled in a randomized, double-blind, crossover study. They received 3 weeks of daily intranasal oxytocin (titrated to 40 IU twice a day) and placebo adjunctive to their antipsychotics. Order of intranasal treatment was randomly assigned and there was a 1-week washout between treatments. RESULTS Analysis of the 15 subjects who completed all the study visits revealed that oxytocin significantly reduced scores on the Positive and Negative Symptom Scale (p < .001) and Clinical Global Impression-Improvement Scale (p < .001) compared with placebo at the 3-week end point. No benefit was seen at the early time points. Oxytocin was well tolerated and produced no adverse effects based upon patient reports or laboratory analysis. CONCLUSIONS The results support the hypothesis that oxytocin has antipsychotic properties and is well tolerated. Higher doses and longer duration of treatment may produce larger benefits and should be evaluated in future studies.

Sensorimotor gating deficits in bipolar disorder patients with acute psychotic mania

BACKGROUND Deficits in sensorimotor gating as assessed by prepulse inhibition (PPI) and habituation of the human startle response have been noted in schizophrenia and other patients with known dysfunction in the brain substrates that regulate PPI. During acute mania, bipolar disorder (BD) and schizophrenia patients present with symptoms that are similar. To determine if these clinical similarities extend to neurophysiologic domains, PPI and startle habituation were assessed in BD patients with acute psychotic mania and compared with a sample of acutely psychotic schizophrenia patients and a normal comparison group. METHODS Fifteen BD patients, 16 schizophrenia patients, and 17 control subjects were assessed on PPI and startle habituation. RESULTS The BD patients had significantly lower PPI than did the control subjects in two of the three PPI conditions (60- and 120-msec interstimulus intervals) as well as less startle habituation. The BD patients did not statistically differ from the schizophrenia patients in PPI or habituation. CONCLUSIONS These findings of sensorimotor gating deficits among bipolar disorder patients are consistent with other findings using different measures of information processing and suggest that the neurobiological substrates underlying sensorimotor gating may be dysregulated during acute manic and psychotic states.

The psychopharmacology of agitation: consensus statement of the American association for emergency psychiatry project BETA psychopharmacology workgroup.

Agitation is common in the medical and psychiatric emergency department, and appropriate management of agitation is a core competency for emergency clinicians. In this article, the authors review the use of a variety of first-generation antipsychotic drugs, second-generation antipsychotic drugs, and benzodiazepines for treatment of acute agitation, and propose specific guidelines for treatment of agitation associated with a variety of conditions, including acute intoxication, psychiatric illness, delirium, and multiple or idiopathic causes. Pharmacologic treatment of agitation should be based on an assessment of the most likely cause of the agitation. If agitation results from a delirium or other medical condition, clinicians should first attempt to treat the underlying cause instead of simply medicating with antipsychotics or benzodiazepines.

Helping oxytocin deliver: considerations in the development of oxytocin-based therapeutics for brain disorders

Concerns regarding a drought in psychopharmacology have risen from many quarters. From one perspective, the wellspring of bedrock medications for anxiety disorders, depression, and schizophrenia was serendipitously discovered over 30 year ago, the swell of pharmaceutical investment in drug discovery has receded, and the pipelines flow of medications with unique mechanisms of action (i.e., glutamatergic agents, CRF antagonists) has slowed to a trickle. Might oxytocin (OT)-based therapeutics be an oasis? Though a large basic science literature and a slowly increasing number of studies in human diseases support this hope, the bulk of extant OT studies in humans are single-dose studies on normals, and do not directly relate to improvements in human brain-based diseases. Instead, these studies have left us with a field pregnant with therapeutic possibilities, but barren of definitive treatments. In this clinically oriented review, we discuss the extant OT literature with an eye toward helping OT deliver on its promise as a therapeutic agent. To this end, we identify 10 key questions that we believe future OT research should address. From this overview, several conclusions are clear: (1) the OT system represents an extremely promising target for novel CNS drug development; (2) there is a pressing need for rigorous, randomized controlled clinical trials targeting actual patients; and (3) in order to inform the design and execution of these vital trials, we need further translational studies addressing the questions posed in this review. Looking forward, we extend a cautious hope that the next decade of OT research will birth OT-targeted treatments that can truly deliver on this systems therapeutic potential.

Rapid acute treatment of agitation in individuals with schizophrenia: multicentre, randomised, placebo-controlled study of inhaled loxapine

BACKGROUND There is a need for a rapid-acting, non-injection, acute treatment for agitation. AIMS To evaluate inhaled loxapine for acute treatment of agitation in schizophrenia. METHOD This phase III, randomised, double-blind, placebo-controlled, parallel-group study (ClinicalTrials.gov number NCT00628589) enrolled 344 individuals who received one, two or three doses of inhaled loxapine (5 or 10 mg) or a placebo. Lorazepam rescue was permitted after dose two. The primary efficacy end-point was change from baseline in Positive and Negative Syndrome Scale-Excited Component (PANSS-EC) 2 h after dose one. The key secondary end-point was Clinical Global Impression-Improvement scale (CGI-I) score 2 h after dose one. RESULTS Inhaled loxapine (5 and 10 mg) significantly reduced agitation compared with placebo as assessed by primary and key secondary end-points. Reduced PANSS-EC score was evident 10 min after dose one with both 5 and 10 mg doses. Inhaled loxapine was well tolerated, and the most common adverse events were known effects of loxapine or minor oral effects common with inhaled medications. CONCLUSIONS Inhaled loxapine provided a rapid, well-tolerated acute treatment for agitation in people with schizophrenia.

Oxytocin modulates psychotomimetic-induced deficits in sensorimotor gating

Abstract Oxytocin plays an important role in the regulation of normal cognitive functions and behaviors, which are disturbed in schizophrenia. Several studies suggest that oxytocinergic function is abnormal in schizophrenia patients. Thus, oxytocin may be involved in the pathophysiology associated with this disorder. This study investigated the regulatory effects of oxytocin on deficits in prepulse inhibition (PPI) associated with schizophrenia. Prepulse inhibition (PPI) is an operational measure of sensorimotor gating which can be measured across many species. PPI is the normal suppression of the startle reflex when the intense startling stimulus (“pulse”) is immediately preceded by a weaker stimulus (“prepulse”). Subcutaneously administered oxytocin (0.04–1.0 mg/kg) dose-dependently restored PPI that had been reduced in rats by dizocilpine, a non-competitive NMDA antagonist, and by amphetamine, an indirect dopamine agonist. Oxytocin did not produce a significant effect on baseline PPI or PPI decreased by the direct dopamine agonist, apomorphine. The underlying startle response amplitude was also not significantly altered by oxytocin. These results suggest that oxytocin may play an important role in the modulation of dopaminergic and glutamatergic regulation of PPI, and that it may act as a novel endogenous antipsychotic.

Adjunctive intranasal oxytocin improves verbal memory in people with schizophrenia

INTRODUCTION Cognitive deficits are a prominent, disabling component of schizophrenia and current pharmacological treatments have demonstrated limited efficacy in their amelioration. Oxytocin - though it has shown promise as a novel antipsychotic in multiple clinical trials - has as-yet poorly characterized effects on cognition, with some evidence indicating an amnestic profile. METHOD As part of a previously reported trial of chronic adjunctive oxytocin in schizophrenia, we measured its effect on two cognitive tests: the CVLT (California Verbal Learning Test) and the LNS (Letter Number Sequence). Tests were performed at baseline and after 3 weeks of treatment. RESULTS We found no evidence for an amnestic effect and, in fact, significantly better performance with oxytocin on several subtests of the CVLT; namely total Recall trials 1-5 (p=0.027), short delayed free recall (p=0.032) and total recall discrimination (p=0.020). In contrast we found no difference between placebo and oxytocin on LNS performance. CONCLUSIONS This is the first report we are aware of documenting a beneficial effect of oxytocin on cognition in schizophrenia. Though from a small sample (n=15), these data both offset past concerns about oxytocins amnestic effects, and may auger another potential benefit in addition to the already-demonstrated salutary effects on other components of the illness.

Oxytocin in schizophrenia: a review of evidence for its therapeutic effects

Background: The suggestion that the neurohormone oxytocin may have clinical application in the treatment of schizophrenia was first published in 1972. Since then, a considerable body of research on a variety of fronts – including several recent double-blind treatment trials – has buttressed these early reports, providing support for the assertion that the oxytocin system is a promising and novel therapeutic target for this devastating malady. Herein, we review the diverse, convergent lines of evidence supporting the therapeutic potential of oxytocin in psychotic illness. Methods: We performed a systematic review of preclinical and clinical literature pertaining to oxytocins role in schizophrenia. Results: Multiple lines of evidence converge to support the antipsychotic potential of oxytocin. These include several animal models of schizophrenia, pharmacological studies examining the impact of antipsychotics on the oxytocin system, human trials in patients examining the aspects of the oxytocin system and several double-blind, placebo-controlled clinical treatment trials. Conclusions: There exists considerable, convergent evidence that oxytocin has potential as a novel antipsychotic with a unique mechanism of action. Auspiciously, based on the few chronic trials to date, its safety profile and tolerability appear very good. That said, several critical clinical questions await investigation before widespread use is clinically warranted.

Efficacy and safety of loxapine for inhalation in the treatment of agitation in patients with schizophrenia: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE The objective of this study was to assess the efficacy and safety of inhaled loxapine in the treatment of agitation in patients with psychotic disorders. METHOD In this randomized, double-blind, placebo-controlled study, 129 agitated patients with schizophrenia or schizoaffective disorder (DSM-IV criteria) were randomized to receive in a clinical or hospital setting a single inhalation of 5 or 10 mg of loxapine or placebo administered using the Staccato loxapine for inhalation device. The inhalation device delivered thermally generated drug aerosol to the deep lung for rapid absorption. The primary efficacy measure was change on the Positive and Negative Syndrome Scale-excited component (PANSS-EC) 2 hours following treatment. Secondary outcomes included the Clinical Global Impressions-Improvement scale (CGI-I), Behavioral Activity Rating Scale (BARS), and time to first rescue medication. The study was conducted between September 2006 and January 2007. RESULTS Differences were statistically significant (P < .05) between placebo and both 5-mg and 10-mg doses on the CGI-I and the CGI-I responder analyses at 2 hours and in time to first rescue medication, and they were statistically significant (P < .05) between placebo and 10-mg loxapine on the PANSS-EC 20 minutes after administration continuing through 2 hours and in change from baseline BARS. Three serious adverse events occurred at least 6 days after treatment, but none were judged related to study treatment. The most common adverse events were sedation and dysgeusia (22% and 17%, respectively, in the 10-mg group, and 14% and 9%, respectively, in the placebo group). CONCLUSIONS Inhaled loxapine was generally safe and well tolerated and produced rapid improvement in agitated patients with psychotic disorders. Statistically significant differences in efficacy were found for the 10-mg dose compared with placebo, with results suggesting 5 mg may be effective. The delivery of loxapine by inhalation may provide a rapid, well-tolerated option for treating acute psychotic agitation that allows patients to avoid the aversive effects and loss of autonomy often associated with use of intramuscular medications. Further investigation of this new loxapine formulation is warranted. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT00369577.

Reversal of sensorimotor gating deficits in Brattleboro rats by acute administration of clozapine and a neurotensin agonist, but not haloperidol: a potential predictive model for novel antipsychotic effects

Prepulse inhibition (PPI) of acoustic startle is decreased in unmedicated schizophrenia patients and similar deficits can be induced in rats through pharmacological, environmental, or neuroanatomical manipulations. Recently, we reported that Brattleboro (BB) rats, a Long Evans (LE) strain with a single gene mutation, have inherent deficits in PPI homologous to those observed in schizophrenia patients. We also reported that PPI deficits in BB rats could be reversed by chronic but not acute administration of 0.5 mg/kg haloperidol. No other dose or drug was tested in that experiment. In this study, we tested the effects of acute subcutaneous administration of several doses of haloperidol as well as the second-generation antipsychotic, clozapine, and the putative novel antipsychotic, PD149163, a neurotensin mimetic that crosses the blood–brain barrier. Consistent with our previous report, BB rats exhibited PPI deficits compared to LE rats and none of the doses of haloperidol produced a significant effect on this PPI deficit. In contrast, 10 and 15 mg/kg of clozapine and all the doses of PD149163 tested reversed the PPI deficits in BB rats. In addition, haloperidol, but not clozapine or PD149163 produced significant catalepsy in BB rats, supporting the notion that PD149163 has a profile consistent with atypical antipsychotics and providing support for the predictive validity of the PPI results. These results further strengthen the notion that the BB rat is a useful predictive model of antipsychotic efficacy and suggest that this model may differentiate between antipsychotics belonging to different therapeutic categories, for example, first- and second-generation agents.