Pharmacologic treatment of first-episode schizophrenia: a review of the literature

Oral versus long-acting injectable antipsychotic in first episode schizophrenia: A 12 weeks interventional study

Background

There is underutilization of long-acting injectable (LAI) antipsychotics for first-episode schizophrenia (FES) despite having convenient dosing and treatment retention. LAIs are predominantly used for patients with poor compliance, chronic course, and multiple relapses.

Materials and Methods

Seventy-two treatment naïve patients with the first episode of Schizophrenia (DSM-5) were assessed for baseline severity of psychopathology using the positive and negative syndrome scale (PANSS) and quality of life (QOL) using the WHOQOL-BREF scale. Patients were randomized to receive either oral haloperidol or LAI haloperidol for a period of 12 weeks.

Results

Both the groups had a significant reduction in PANSS scores and improvement in QoL over 12 weeks period (P = 0.0001). The LAI group showed greater adherence and significantly better quality of life than the oral group (P = 0.023). The mean numbers of side effects were less in the LAI group at week 2 as compared to the oral group.

Conclusion

LAI haloperidol is similar to oral haloperidol in patients with FES with respect to treatment response and offers benefits in form of a lesser number of side effects during early treatment, overall better adherence rates, and better QOL.

Activity-State Dependent Reversal of Ketamine-Induced Resting State EEG Effects by Clozapine and Naltrexone in the Freely Moving Rat

Ketamine is a non-competitive N-Methyl-D-aspartate receptor (NMDAR) antagonist used in the clinic to initiate and maintain anaesthesia; it induces dissociative states and has emerged as a breakthrough therapy for major depressive disorder. Using local field potential recordings in freely moving rats, we studied resting state EEG profiles induced by co-administering ketamine with either: clozapine, a highly efficacious antipsychotic; or naltrexone, an opioid receptor antagonist reported to block the acute antidepressant effects of ketamine. As human electroencephalography (EEG) is predominantly recorded in a passive state, head-mounted accelerometers were used with rats to determine active and passive states at a high temporal resolution to offer the highest translatability. In general, pharmacological effects for the three drugs were more pronounced in (or restricted to) the passive state. Specifically, during inactive periods clozapine induced increases in delta (0.1-4 Hz), gamma (30-60 Hz) and higher frequencies (>100 Hz). Importantly, it reversed the ketamine-induced reduction in low beta power (10-20 Hz) and potentiated ketamine-induced increases in gamma and high frequency oscillations (130-160 Hz). Naltrexone inhibited frequencies above 50 Hz and significantly reduced the ketamine-induced increase in high frequency oscillations. However, some frequency band changes, such as clozapine-induced decreases in delta power, were only seen in locomoting rats. These results emphasise the potential in differentiating between activity states to capture drug effects and translate to human resting state EEG. Furthermore, the differential reversal of ketamine-induced EEG effects by clozapine and naltrexone may have implications for the understanding of psychotomimetic as well as rapid antidepressant effects of ketamine.

Patterns of Care for Adolescent With Schizophrenia: A Delphi-Based Consensus Study

BACKGROUND

The current conceptualization of schizophrenia as neurodevelopmental disorder should lead to innovative public health policies in terms of a reorganization of the mental health care systems, particularly in the transition from adolescence to adulthood, to reduce personal, familiar, and social costs and burdens. The purpose of the project was to perform a survey among a panel of Italian schizophrenia experts, to share evidence-based information on adolescent schizophrenia and explore the degree of consensus among professionals in the following four macro-areas: early diagnosis; pharmacological treatment; health care system organization and transition process from adolescent to adulthood; and psychosocial interventions.

METHODS

The consensus process consisted of a two-step web-based Delphi method, which took place between June and November 2021. The survey was developed by a panel of four psychiatrists and four child neuropsychiatrists, identified as key opinion leaders (KOLs). The KOLs identified 21 statements involving a total of 70 items with a major need of clarification on early-onset schizophrenia (EOS). The survey was distributed to 86 specialists in psychiatry and child neuropsychiatry.

RESULTS

The results revealed a large agreement among the expert group on all the investigated areas of adolescent schizophrenia patterns of care and management. Consensus was ultimately reached for 67 items of the Delphi survey (95.7%), while negative consensus was reached for 2 items and no consensus was reached for 1 item.

CONCLUSIONS

Overall, results showed a significant gap between the acquired scientific knowledge and clinical practice. In this scenario, it should be necessary to plan specific initiatives at a multiple level, to edit recommendations on clinical decision-making, as well as to prompt changes at the political and organizational levels, also involving scientific societies, patients, and family associations, to overcome the barriers that delay the implementation process.

The efficacy, acceptability, and safety of five atypical antipsychotics in patients with first-episode drug-naïve schizophrenia: a randomized comparative trial

BACKGROUND

Differences in effectiveness and tolerability between different atypical antipsychotics may affect schizophrenic patients' treatment adherence or prognosis. However, which kind of antipsychotic was more effective and safe in the treatment of schizophrenia is still being debated. This study attempted to understand whether there are any differences in efficacy, acceptability, and safety between the five atypical antipsychotics in patients with first-episode schizophrenia.

METHODS

Two hundred cases of inpatients with first-episode drug-naïve schizophrenia were randomly assigned to 6-8 weeks of treatment with either of aripiprazole, risperidone, quetiapine, olanzapine, or ziprasidone from October 2012 to November 2014. The efficacy, acceptability, and safety measurement after 6-8 weeks of treatment of the five kinds of antipsychotics were evaluated by the deduction rate of Brief Psychiatric Rating Scale (BPRS) total score, the proportion of treatment discontinuation, and adverse events, respectively. Whether the treatment discontinuation or combination therapy for baseline antipsychotics after titration mainly depended on ineffective or less effective on an initial-assigned antipsychotic during the study period.

RESULTS

BPRS total scores in each antipsychotic group were significantly decreased at the end of the study (P < 0.01), and only the deduction rate of BPRS total scores in the risperidone group was markedly higher than those in the groups of aripiprazole (P < 0.01) and olanzapine (P < 0.05) after controlling the impact of the differences of age of onset. There were significant differences between quetiapine (χ² = 5.46, P = 0.019), olanzapine (χ² = 5.6, P = 0.018), and ziprasidone regarding the proportion of maintaining on initially allocated therapy. In addition, the difference in treatment discontinuation between male and female patients was also significant (χ² = 9.897, P = 0.002), and odds ratio of treatment discontinuation in male and female patients was 0.37 (95% CI 0.198-0.693); however, no difference in treatment discontinuation was found between five antipsychotics. Extrapyramidal symptoms in the groups of quetiapine and olanzapine were notably less than the other three kinds of antipsychotics (P < 0.05), but there were no significant differences in other adverse events between the five antipsychotic groups.

CONCLUSIONS

Risperidone was more effective than aripiprazole and olanzapine in treating first-episode schizophrenia. The present study revealed the superiority of quetiapine and olanzapine over ziprasidone with remarkably less severe extrapyramidal adverse effects, especially with lower drop-out and treatment discontinuation. There were no differences in terms of other adverse events although the risk of treatment discontinuation was higher in female patients. Trial registration 2012-3-88. Registered 20 July 2012.

Microbiome to Brain: Unravelling the Multidirectional Axes of Communication

The gut microbiome plays a crucial role in host physiology. Disruption of its community structure and function can have wide-ranging effects making it critical to understand exactly how the interactive dialogue between the host and its microbiota is regulated to maintain homeostasis. An array of multidirectional signalling molecules is clearly involved in the host-microbiome communication. This interactive signalling not only impacts the gastrointestinal tract, where the majority of microbiota resides, but also extends to affect other host systems including the brain and liver as well as the microbiome itself. Understanding the mechanistic principles of this inter-kingdom signalling is fundamental to unravelling how our supraorganism function to maintain wellbeing, subsequently opening up new avenues for microbiome manipulation to favour desirable mental health outcome.

Physiologically based pharmacokinetic modelling to predict single- and multiple-dose human pharmacokinetics of bitopertin

BACKGROUND

Bitopertin (RG1678) is a glycine reuptake inhibitor currently in phase 3 trials for treatment of schizophrenia. This paper describes the use of physiologically based pharmacokinetic (PBPK) modelling and preclinical data to gain insights into and predict bitopertin clinical pharmacokinetics.

METHODS

Simulations of pharmacokinetics were initiated early in the drug discovery stage by integrating physicochemical properties and in vitro measurements into a PBPK rat model. Comparison of pharmacokinetics predicted by PBPK modelling with those measured after intravenous and oral dosing in rats and monkeys showed a good match and thus increased confidence that a similar approach could be applied for human prediction. After comparison of predicted plasma concentrations with those measured after single oral doses in the first clinical study, the human model was refined and then applied to simulate multiple-dose pharmacokinetics.

RESULTS

Clinical plasma concentrations measured were in good agreement with PBPK predictions. Predicted area under the plasma concentration-time curve (AUC) was within twofold of the observed mean values for all dose levels. Maximum plasma concentration (C max) at higher doses was well predicted but approximately twofold below observed values at the lower doses. A slightly less than dose-proportional increase in both AUC and C max was observed, and model simulations indicated that when the dose exceeded 50 mg, solubility limited the fraction of dose absorbed. Refinement of the absorption model with additional solubility and permeability measurements further improved the match of simulations to observed single-dose data. Simulated multiple-dose pharmacokinetics with the refined model were in good agreement with observed data.

CONCLUSIONS

Clinical pharmacokinetics of bitopertin can be well simulated with a mechanistic PBPK model. This model supports further clinical development and provides a valuable repository for pharmacokinetic knowledge gained about the molecule.

Use of allosteric targets in the discovery of safer drugs

The need for drugs with fewer side effects cannot be overemphasized. Today, most drugs modify the actions of enzymes, receptors, transporters and other molecules by directly binding to their active (orthosteric) sites. However, orthosteric site configuration is similar in several proteins performing related functions and this leads to a lower specificity of a drug for the desired protein. Consequently, such drugs may have adverse side effects. A new basis of drug discovery is emerging based on the binding of the drug molecules to sites away (allosteric) from the orthosteric sites. It is possible to find allosteric sites which are unique and hence more specific as targets for drug discovery. Of many available examples, two are highlighted here. The first is caloxins - a new class of highly specific inhibitors of plasma membrane Ca²⁺ pumps. The second concerns the modulation of receptors for the neurotransmitter acetylcholine, which binds to 12 types of receptors. Exploitation of allosteric sites has led to the discovery of drugs which can selectively modulate the activation of only 1 (M1 muscarinic) out of the 12 different types of acetylcholine receptors. These drugs are being tested for schizophrenia treatment. It is anticipated that the drug discovery exploiting allosteric sites will lead to more effective therapeutic agents with fewer side effects.