L-deprenyl in treating negative symptoms of schizophrenia

Efficacy and safety of selegiline across different psychiatric disorders: A systematic review and meta-analysis of oral and transdermal formulations

Selegiline is an irreversible, selective type-B monoamine oxidase inhibitor (MAOI) approved for Parkison's disease-oral and major depressive disorder-transdermal formulation) resulting in non-selective MAOI activity at oral doses≥20 mg/day. The present systematic review and meta-analysis appraises the evidence of different formulations/dosages of selegiline across different psychiatric conditions. We inquired PubMed/MEDLINE/Cochrane-Central/WHO-ICTRP/Clarivate-WebOfScience and the Chinese-Electronic-Journal Database from inception to 10/26/2022 for selegiline trials involving psychiatric patients. Random-effects meta-analyses assessed heterogeneity, publication/risk biases, and confidence in the evidence, followed by sensitivity, subgroup, and meta-regression analyses. Co-primary outcomes were: changes in symptom score (standardized mean difference=SMD) and author-defined response (risk ratios=RRs). RRs of adverse events and all-cause discontinuation were secondary and acceptability outcomes, respectively. Systematic-review included 42 studies; meta-analysis, 23. Selegiline outperformed placebo in depressive symptom reduction (SMD=-0.96, 95%C.I.=-1.78, -0.14, k = 10, n = 1,308), depression (RR=1.61, 95%C.I.=1.20, 2.15, k = 9, n = 1,238) and atypical-depression response (RR=2.23, 95%C.I.=1.35, 3.68, k = 3, n = 136). Selegiline failed to outperform the placebo in negative (k = 4) or positive symptoms of schizophrenia (k = 4), attention-deficit-hyperactivity disorder (ADHD) symptoms reduction (k = 2), and smoking abstinence rate (k = 4). Selegiline did not differ from methylphenidate and ADHD scores (k = 2). No significant difference emerged in acceptability, incident diarrhea, headache, dizziness, and nausea RRs, in contrast to xerostomia (RR=1.58, 95%C.I. =1.03, 2.43, k = 6, n = 1,134), insomnia (RR=1.61, 95%C.I.=1.19, 2.17, k = 10, n = 1,768), and application-site reaction for transdermal formulation (RR=1.81, 95%C.I.=1.40, 2.33, k = 6, n = 1,662). Confidence in findings was low/very-low for most outcomes; moderate for depressive symptoms reduction (transdermal). Selegiline proved effective, safe, and well-tolerated for depressive disorders, yet further evidence is warranted about specific psychiatric disorders.

Altered states, alkaloids, and catatonia: Monoaminoxidase inhibitors and their role in the history of psychopharmacology

Monoamine oxidases are mitochondrial enzymes that catalyze the oxidative deamination of biogenic amines (adrenaline, noradrenaline, serotonin, and dopamine), causing their inactivation and subsequently playing a fundamental role in the homeostasis of various neurotransmitters. As the regulation of these effects was deemed important in clinical practice, numerous modulators of these enzymes were tested for various clinical effects. The purpose of this paper is to present a few historical landmarks regarding monoaminoxidase inhibitors and their usefulness as psychopharmacological agents. We will be focusing on banisterine, iproniazid, selegiline, rasagiline, tranylcypromine, moclobemide, and their role in the history of psychopharmacology. An almost unknown fact is that harmine, an MAO-A alkaloid, was used as early as the latter half of the 1920s in Bucharest, to reduce catatonic symptoms in schizophrenia, thus ushering the dawn of psychopharmacology era which started with chlorpromazine in the 1950s.

The Role of Selegiline in the Treatment of Negative Symptoms Associated with Schizophrenia

Objective:

To evaluate the role of selegiline in the treatment of negative symptoms associated with schizophrenia.

Data Sources:

MEDLINE (1966–January 2007) and PsychINFO (1967–January 2007) were searched, using the terms schizophrenia, negative symptoms, and selegiline. A bibliographic search was conducted, as well.

Study Selection and Data Extraction:

All English-language articles identified from the search were evaluated. All primary literature was included in the review.

Data Synthesis:

Based on its dopamine-enhancing property, selegiline has been studied as augmentation to antipsychotic therapy for the treatment of negative symptoms associated with schizophrenia. The efficacy of low-dose oral selegiline for the treatment of negative symptoms has been evaluated in 1 case report, 2 open-label trials, and 2 controlled trials. The case report and both open-label trials report improvement of negative symptoms associated with low-dose oral selegiline. In 1 of the controlled trials, selegiline showed no difference in effect from that of placebo. These data are limited by small sample sizes. The largest controlled trial demonstrated a statistically significant difference between selegiline and placebo; however, the clinical significance is questionable, given that patients treated with selegiline were still experiencing marked negative symptoms at study completion. No comparative studies evaluating low-dose oral selegiline versus other augmentative treatment options for negative symptoms associated with schizophrenia exist at this time.

Conclusions:

Given the limitations of current literature, low-dose oral selegiline cannot be recommended for treatment of negative symptoms associated with schizophrenia. Additional controlled trials are needed to better delineate whether there is a role for selegiline in decreasing the burden of negative symptoms associated with schizophrenia.

Rasagiline in the Treatment of the Persistent Negative Symptoms of Schizophrenia

OBJECTIVE

The current study examined the efficacy and safety of rasagiline, a selective MAO-B inhibitor, for the treatment of persistent negative symptoms.

METHODS

Sixty people with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, schizophrenia or schizoaffective disorder, who met a priori criteria for persistent negative symptoms, were randomized to receive rasagiline, 1mg/d (n = 31) or placebo (n = 29) in a 12-week, double-blind, placebo-controlled clinical trial. The Scale for the Assessment of Negative Symptoms (SANS) total score was used to assess change in negative symptoms. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), N-Back test, a probabilistic learning task, and a delayed discounting task were used to assess cognition.

RESULTS

In a mixed model analysis of covariance (MM-ANCOVA), with time as a continuous variable, there was a significant treatment × time effect for SANS total score (F = 5.61(df = 1,40.3), P = .023). The treatment × time interaction effect was also significant for the SANS avolition subscale score (F(1,40.2) = 10.41, P = .002). In a post hoc MM-ANCOVA analyses, with time as a categorical variable, group differences were significant at week 12 for SANS total score (t(37.3) = 2.15; P = .04; d = -0.41) and SANS avolition subscale score (t(49.0) = 3.06; P = .004; d = -0.46). There was a significant difference in number of participants with a ≥20% reduction in SANS avolition score (χ(2)(1) = 10.94; P = .0009), but not in SANS total score (χ(2)(1) = 1.11; P = .29). There were no significant group differences on the RBANS, N-Back, probabilistic learning, or delayed discounting tasks.

CONCLUSIONS

Study results support future studies of the utility of rasagiline for the treatment of negative symptoms, including avolition (clinicaltrials.gov trial number: NCT00492336).

Evidence-based guidelines for the pharmacological treatment of schizophrenia: recommendations from the British Association for Psychopharmacology

These guidelines from the British Association for Psychopharmacology address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting, involving experts in schizophrenia and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from the participants and interested parties, and cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. The practice recommendations presented are based on the available evidence to date, and seek to clarify which interventions are of proven benefit. It is hoped that the recommendations will help to inform clinical decision making for practitioners, and perhaps also serve as a source of information for patients and carers. They are accompanied by a more detailed qualitative review of the available evidence. The strength of supporting evidence for each recommendation is rated.

Medications Development for the Treatment of Nicotine Dependence in Individuals with Schizophrenia

The development of medications for the treatment of nicotine dependence in patients with schizophrenia is a public health priority due to its high prevalence rates, devastating medical consequences, and difficulty to treat. It has been hypothesized that the high prevalence of nicotine dependence among patients with schizophrenia may be due to a shared neurobiological vulnerability. This shared vulnerability has been evidenced in reports showing that nicotine improves neuropsychological deficits associated with schizophrenia such as in the P50 evoked auditory potentials, spatial working memory, and attention. The common pathophysiologic pathways of smoking and schizophrenia may serve as the basis for the pharmacological evaluation of medications for the treatment of these concurrent disorders. Currently, little research of medications for the treatment of this comorbidity has been conducted. Studies have evaluated the efficacy of smoking cessation medications in patients with schizophrenia. These include the nicotine replacement therapy (patch, nasal spray) and sustained release bupropion. Others have evaluated the anti-smoking effect of medications (e.g., clozapine, haloperidol) used for the treatment of schizophrenia. In both cases, the results have not been conclusive. Newer smoking cessation approaches such as varenicline, selegiline, rimonabant, and nicotine vaccine, among others, have yet to be tested in this population. The purpose of this article is to review the results of the studies conducted to date and propose some potential pharmacotherapies based on the current knowledge of the pathophysiology of both disorders.

Treatments for schizophrenia: a critical review of pharmacology and mechanisms of action of antipsychotic drugs

The treatment of schizophrenia has evolved over the past half century primarily in the context of antipsychotic drug development. Although there has been significant progress resulting in the availability and use of numerous medications, these reflect three basic classes of medications (conventional (typical), atypical and dopamine partial agonist antipsychotics) all of which, despite working by varying mechanisms of actions, act principally on dopamine systems. Many of the second-generation (atypical and dopamine partial agonist) antipsychotics are believed to offer advantages over first-generation agents in the treatment for schizophrenia. However, the pharmacological properties that confer the different therapeutic effects of the new generation of antipsychotic drugs have remained elusive, and certain side effects can still impact patient health and quality of life. Moreover, the efficacy of antipsychotic drugs is limited prompting the clinical use of adjunctive pharmacy to augment the effects of treatment. In addition, the search for novel and nondopaminergic antipsychotic drugs has not been successful to date, though numerous development strategies continue to be pursued, guided by various pathophysiologic hypotheses. This article provides a brief review and critique of the current therapeutic armamentarium for treating schizophrenia and drug development strategies and theories of mechanisms of action of antipsychotics, and focuses on novel targets for therapeutic agents for future drug development.

Deprenyl augmentation for treating negative symptoms of schizophrenia: a double-blind, controlled study

Augmentation of dopaminergic neurotransmission has been suggested as a treatment strategy for negative symptoms of schizophrenia. On the basis of open studies that reported the potential benefit of deprenyl (selegiline) as augmentation to antipsychotic treatment, this double-blind, controlled study was designed to further address this question. Sixteen schizophrenic patients with predominately negative symptoms, manifesting clinical stability on maintenance antipsychotic treatment, were randomly assigned to receive either deprenyl 15 mg/day or placebo in addition to their antipsychotic treatment for 8 weeks. Clinical follow-up and ratings were done during this period and for 8 more weeks after deprenyl discontinuation. Both groups showed a statistically significant but clinically marginal improvement over the 8 weeks of deprenyl or placebo treatment. This improvement was abolished during the postdiscontinuation follow-up period. Deprenyl at a dose of 15 mg/day did not offer therapeutic benefit in our patients. A significant placebo effect was observed, which may be the result of increased patient-doctor contact during the study.

The clinical potential of Deprenyl in neurologic and psychiatric disorders

This article reviews the results of clinical studies with Deprenyl in various neurologic and psychiatric disorders except Parkinson's disease. Promising results could be observed both in narcolepsy in a dose of at least 20 mg/day in three different trials and in one study of Tourette's syndrome including attention hyperactivity disorders using an average dosis of 8.1 mg/ day. Controversial results were reported for Alzheimer's disease. On the one hand significant improvement of cognitive functions was found by various authors. On the other hand in a more recent study no effect on the progression of the disease could be observed. For depression a higher dosage of deprenyl between 30 to 60 mg/day appears to be necessary for effective treatment. No positive results were found in amyotrophic lateral sclerosis and in tardive dyskinesias.

Determination of amphetamine, methamphetamine and desmethyldeprenyl in human plasma by gas chromatography/negative ion chemical ionization mass spectrometry

A sensitive and specific assay for the quantitative determination of amphetamine, methamphetamine and desmethyldeprenyl in human plasma specimens is described. Electron capture/negative ion chemical ionization gas chromatography/mass spectrometry is used to determine the extracted plasma concentrations of the three target compounds as their N-heptafluorobutyryl derivatives. Quantitation is performed by stable isotope dilution using d6-amphetamine and d6-methamphetamine as internal standards. Selected ion monitoring of the [M-HF]- ions of both the analytes and internal standards results in minimum quantifiable limits of 0.10 ng ml-1 for both amphetamine and methamphetamine and 0.25 ng ml-1 for desmethyldeprenyl. Excellent linearity (r = 0.998) up to at least 5.00 ng ml-1 is demonstrated.