Pharmacokinetic Evaluation of Blonanserin Transdermal Patch: Population Analysis and Simulation of Plasma Concentration and Dopamine D2 Receptor Occupancy in Clinical Settings

Population pharmacokinetics of blonanserin in Japanese adolescent and adult patients with schizophrenia

The second-generation antipsychotic blonanserin is a highly selective, full antagonist of dopamine D2 and D3 and serotonin 5-HT2A receptors. It is currently prescribed for patients with schizophrenia in Japan. We aimed to develop a population pharmacokinetic model of oral blonanserin, including data from 12 to 77 years old patients, to assess the covariates that influence blonanserin pharmacokinetics and evaluate appropriate dosage regimens in adolescents versus adults. The population pharmacokinetic analysis was conducted using plasma concentrations in 132 Japanese adolescent and 135 adult patients with schizophrenia (including 20 older adults [≥65 years] patients), and 49 healthy adults. The blonanserin population pharmacokinetics was described using a two-compartment model with first-order absorption with lag time. Relative bioavailability decreased in fasted conditions and with concomitant CYP3A4 inducer use. Apparent clearance in older adult was lower than adult and adolescent. Simulation revealed similar plasma exposures between adolescents and adults and slightly larger in older adults. Bayesian estimates of apparent clearance suggested no effects of age in adolescents between 12 and 18 years old. Together, these results reveal the pharmacokinetic characteristics of blonanserin over a wide age range and support the appropriateness of the approved dosing regimen for adolescent patients with schizophrenia in Japan.

Optimisation of pharmacotherapy in psychiatry through therapeutic drug monitoring, molecular brain imaging and pharmacogenetic tests: Focus on antipsychotics

BACKGROUND

For psychotic disorders (i.e. schizophrenia), pharmacotherapy plays a key role in controlling acute and long-term symptoms. To find the optimal individual dose and dosage strategy, specialised tools are used. Three tools have been proven useful to personalise drug treatments: therapeutic drug monitoring (TDM) of drug levels, pharmacogenetic testing (PG), and molecular neuroimaging.

METHODS

In these Guidelines, we provide an in-depth review of pharmacokinetics, pharmacodynamics, and pharmacogenetics for 45 antipsychotics. Over 30 international experts in psychiatry selected studies that have measured drug concentrations in the blood (TDM), gene polymorphisms of enzymes involved in drug metabolism, or receptor/transporter occupancies in the brain (positron emission tomography (PET)).

RESULTS

Study results strongly support the use of TDM and the cytochrome P450 (CYP) genotyping and/or phenotyping to guide drug therapies. Evidence-based target ranges are available for titrating drug doses that are often supported by PET findings.

CONCLUSION

All three tools discussed in these Guidelines are essential for drug treatment. TDM goes well beyond typical indications such as unclear compliance and polypharmacy. Despite its enormous potential to optimise treatment effects, minimise side effects and ultimately reduce the global burden of diseases, personalised drug treatment has not yet become the standard of care in psychiatry.

Successful Management of Terminal Delirium With Transdermal Blonanserin Patch in a Terminally Ill Cancer Patient

Delirium is a distressing condition in terminally ill cancer patients, often treated with antipsychotics. Administering them orally, subcutaneously, or intravenously can be challenging in severely agitated patients. Transdermal antipsychotic patches offer an alternative, but their use for terminal delirium remains underexplored. We present the case of a 73-year-old man with advanced diffuse large B cell lymphoma who developed severe mixed delirium during third-line chemotherapy. Nonpharmacological interventions and oral risperidone plus intravenous haloperidol failed to improve his condition. Subsequently, a transdermal blonanserin patch was applied, resulting in the resolution of hallucinations on day 1 and agitation on day 3, allowing improved communication. The patch was easily applied daily without notable adverse events. However, he deteriorated a week later with an estimated survival of days, ultimately requiring continuous midazolam for refractory agitation. This case underscores the potential of transdermal blonanserin patches for delirium in terminally ill cancer patients, emphasizing the need for future prospective studies.

Novel therapies for nausea and vomiting in advanced illness and supportive cancer care

Nausea and vomiting are common experiences and are often dreaded more than pain. This review discusses blonanserin, mirtazapine, and isopropyl alcohol as antiemetics. Blonanserin, an atypical antipsychotic with a high affinity for dopamine D2 and D3 receptors and serotonin receptor 5-HT2A, has less of a risk of extrapyramidal adverse effects. Transdermal blonanserin, available in Korea, Japan, and China in a small number of trials, has improved nausea in patients not responding to standard antiemetics. Mirtazapine is a noradrenergic and specific serotonergic antidepressant that has been used for multiple symptoms besides depression. There is little evidence that mirtazapine improves anorexia or nausea in advanced cancer but is as effective as olanzapine in reducing chemotherapy-induced nausea and vomiting. Isopropyl alcohol aromatherapy has been successfully used in the emergency department for nausea and vomiting with an onset to benefit more rapidly than standard antiemetics. Isopropyl alcohol prep pads can be used for home-going antiemetic therapy and as a bridge to treating acute nausea until standard antiemetics take effect.

Translation from Preclinical Research to Clinical Trials: Transdermal Drug Delivery for Neurodegenerative and Mental Disorders

Neurodegenerative diseases (NDs), particularly dementia, provide significant problems to worldwide healthcare systems. The development of therapeutic materials for various diseases has a severe challenge in the form of the blood-brain barrier (BBB). Transdermal treatment has recently garnered widespread favor as an alternative method of delivering active chemicals to the brain. This approach has several advantages, including low invasiveness, self-administration, avoidance of first-pass metabolism, preservation of steady plasma concentrations, regulated release, safety, efficacy, and better patient compliance. Topics include the transdermal method for therapeutic NDs, their classification, and the mechanisms that allow the medicine to enter the bloodstream through the skin. The paper also discusses the obstacles and potential outcomes of transdermal therapy, emphasizing the benefits and drawbacks of different approaches.

Gene Polymorphisms and Drug-Drug Interactions Determine the Metabolic Profile of Blonanserin

This study aimed to evaluate the effects of cytochrome P450 3A4 (CYP3A4) gene polymorphism and drug interaction on the metabolism of blonanserin. Human recombinant CYP3A4 was prepared using the Bac-to-Bac baculovirus expression system. A microsomal enzyme reaction system was established, and drug-drug interactions were evaluated using Sprague-Dawley rats. Ultra-performance liquid chromatography-tandem mass spectrometry was used to detect the concentrations of blonanserin and its metabolite. Compared with wild type CYP34A, the relative clearance of blonanserin by CYP3A4.29 significantly increased to 251.3%, while it decreased notably with CYP3A4.4, 5, 7, 8, 9, 10, 12, 13, 14, 16, 17, 18, 23, 24, 28, 31, 33, and 34, ranging from 6.09% to 63.34%. Among 153 tested drugs, nimodipine, felodipine, and amlodipine were found to potently inhibit the metabolism of blonanserin. Moreover, the inhibitory potency of nimodipine, felodipine, and amlodipine varied with different CYP3A4 variants. The half-maximal inhibitory concentration and enzymatic kinetics assay demonstrated that the metabolism of blonanserin was noncompetitively inhibited by nimodipine in rat liver microsomes and was inhibited in a mixed manner by felodipine and amlodipine in both rat liver microsomes and human liver microsomes. When nimodipine and felodipine were coadministered with blonanserin, the area under the blood concentration-time curve (AUC)(0-t), AUC(0-∞), and C max of blonanserin increased. When amlodipine and blonanserin were combined, the C max of blonanserin C increased remarkably. The vast majority of CYP3A4 variants have a low ability to catalyze blonanserin. With combined administration of nimodipine, felodipine, and amlodipine, the elimination of blonanserin was inhibited. This study provides the basis for individualized clinical use of blonanserin. SIGNIFICANCE STATEMENT: The enzyme kinetics of novel CYP3A4 enzymes for metabolizing blonanserin were investigated. Clearance of blonanserin by CYP3A4.4, 5, 7-10, 12-14, 16-18, 23-24, 28, 31, 33, and 34 decreased notably, but increased with CYP3A4.29. Additionally, we established a drug interaction spectrum for blonanserin, in which nimodipine, felodipine, and amlodipine kinetics exhibited mixed inhibition. Moreover, their inhibitory potencies decreased with CYP3A4.4 and 5 compared to CYP3A4.1. This study provides essential data for personalized clinical use of blonanserin.

Switching from blonanserin oral tablets/powders to transdermal patches alleviates extrapyramidal symptoms in patients with schizophrenia: A 52-week open-label study

Blonanserin is a second-generation antipsychotic for the treatment of schizophrenia. Blonanserin has two different routes of administration: oral tablets/powder and transdermal patches. The aim of this study was to investigate as a post-hoc analysis of an original study whether switching from blonanserin tablets/powders to transdermal patches would reduce extrapyramidal symptoms (EPS) and/or the dose of antiparkinsonian drugs for the stabilization of blood pharmacokinetics in patients with schizophrenia. Patients with schizophrenia (n = 155) were enrolled in either cohort 1 or 2. In cohort 1 (n = 97), patients received 40-80 mg/day blonanserin transdermal patches for one year after taking 8-16 mg/day blonanserin tablets for 6 weeks, and the dose of patches was determined based on the dose of the tablets. In cohort 2 (n = 58), all patients started with 40 mg/day blonanserin patches and then received 40-80 mg/day for a year after taking blonanserin tablets/powders. Changes from the start of transdermal patch treatment in EPS and the dose of antiparkinsonian drugs at 3, 6, and 12 months were assessed using the Drug-Induced EPS Scale (DIEPSS) and biperiden equivalents of total antiparkinsonian drugs (BPD-eq), respectively. Among 155 patients, only four patients in cohort 1 discontinued owing to EPS during a patch period. Significant improvements from the start of patch treatment in the DIEPSS total score at any point were observed (mean change±SD): -0.44 ± 1.50 (p = 0.013), -0.07 ± 1.78 (p = 0.73), and - 0.14 ± 1.37 (p = 0.44) in cohort 1 and - 0.16 ± 1.32 (p = 0.40), -0.74 ± 1.92 (p = 0.020), and - 0.81 ± 2.22 (p = 0.047) in cohort 2 at 3, 6, and 12 months, respectively. In contrast, there were no significant changes from the start of patch treatment in BPD-eq at any month (p > 0.05). Transdermal patches of blonanserin are a more effective route of administration to diminish EPS than oral tablets/powder.

Prediction of Corresponding Dose of Transdermal Blonanserin to Oral Dose Based on Dopamine D2 Receptor Occupancy: Unique Characteristics of Blonanserin Transdermal Patch

BACKGROUND/PURPOSE

Blonanserin is an atypical antipsychotic, a potent selective antagonist of dopamine D2 receptor (D2), prescribed as oral formulations in patients with schizophrenia. Blonanserin transdermal patch was developed to provide a new treatment option, but the corresponding dose to oral blonanserin was not clear. The aims of this study were to clarify the pharmacokinetic (PK)-pharmacodynamic characteristics of blonanserin after transdermal patch application and to evaluate the corresponding dose to oral formulation based on striatal D2 occupancy.

METHODS

The relationship between D2 occupancy and plasma blonanserin concentration was analyzed using an Emax model based on data from positron emission tomography study with oral and transdermal blonanserin. D2 occupancy was simulated using Emax models based on the observed plasma concentrations and the simulated plasma concentrations obtained from population PK model.

RESULTS

Plasma blonanserin concentration levels after repeated patch applications were nearly stable throughout the day and no effect of sex, advanced age, or application site was detected. The concentration at half maximal D2 occupancy during transdermal patch applications, 0.857 ng/mL, was higher than that after oral doses, 0.112 ng/mL, suggesting metabolite contribution after oral doses. The median predicted D2 occupancy during blonanserin patch applications at doses of 40 and 80 mg/d was 48.7% and 62.5%, respectively, and the distribution of D2 occupancy at these doses could cover most of that at oral doses of 8 to 24 mg/d.

CONCLUSIONS

Predicted D2 occupancy suggested that a 40- to 80-mg/d blonanserin transdermal patch dose corresponds to an 8- to 24-mg/d oral dose for the treatment of schizophrenia.