Switching from blonanserin tablets to blonanserin transdermal patches improves tardive dyskinesia: A case report

Abstract Tardive dyskinesia (TD) is a common side effect of antipsychotics, and it remains a persistent and challenging problem. The blonanserin transdermal patch, developed in Japan and launched in September 2019, is the first antipsychotic transdermal treatment. Here, we describe a patient with schizophrenia who exhibited markedly improved orofacial dyskinesia after switching from blonanserin tablets to blonanserin transdermal patches. We speculate that the patch formulation might have led to more stable plasma blonanserin levels, thus reducing the side effects. Specifically, the patch formulation might have contributed to stable plasma levels via the continuous and direct absorption of blonanserin through the skin.


| INTRODUC TI ON
Tardive dyskinesia (TD) is a common side effect of antipsychotics. It often causes physical and emotional distress in individuals and affects their quality of life. 1 Despite the advent of atypical or secondgeneration antipsychotics, which have a lower risk of complications, TD remains a persistent and challenging problem. 2 Blonanserin is a second-generation antipsychotic commonly used in Asian countries (eg, Japan and Korea) with a unique pharmacological profile. 3 Compared with other second-generation antipsychotics, it is characterized by higher dopamine D2 receptor occupancy and lower serotonin 2A receptor blockade, 4 and improves not only positive symptoms of schizophrenia but also cognitive symptoms and some social functions. [5][6][7][8] The efficacy of blonanserin for schizophrenia is comparable to that of other antipsychotics, and it is well tolerated, with a lower risk of weight gain and hyperprolactinemia compared with other second-generation antipsychotics. 7,8 The blonanserin transdermal patch (blonanserin tape), developed in Japan and launched in September 2019, is the first form of antipsychotic transdermal therapy in the world. It was developed as an alternative to blonanserin tablets to improve adherence and stabilize blood levels of the drug. 9 Here, we describe a patient with schizophrenia who exhibited a marked improvement in orofacial dyskinesia after switching from blonanserin tablets to blonanserin transdermal patches. To the best of our knowledge, this is the first such case report.

| C A S E PRE S ENTATI ON
The patient was a 61-year-old woman with schizophrenia who had orofacial dyskinesia.
She had no previous physical problem and family history of psychiatric disorders. The patient was healthy during her school years. She graduated from nursing school and began to work at the age of 22. At the age of 43, several psychiatric symptoms, including insomnia, anxiety, and mood swings, began to appear.
Aged 45, the patient started to experience auditory hallucinations, thought insertions, and delusions. She was diagnosed with schizophrenia and was prescribed olanzapine (1.25-5 mg/d), which was effective against her symptoms. She continued to work as a nurse until she was 60 years old and then retired. However, at the age of 61, she refused medication and her psychotic symptoms worsened. She jumped off a bridge and fell into a river while experiencing an auditory hallucination, and was transported to hospital because of a whole-body fracture. When her physical condition had improved, she was transferred to the psychiatric hospital, and inpatient psychiatric treatment was initiated. She first resumed treatment with olanzapine (5 mg/d), but this was discontinued because of hyperglycemia. Next, she was treated with paliperidone  Table 1.

| D ISCUSS I ON
Antipsychotics, including blonanserin, can reduce symptoms of schizophrenia by acting on dopamine D2 receptors in the brain. 12,13 However, blonanserin is associated with a relatively high incidence of EPSs, and EPS incidence during treatment is mainly determined by the plasma concentration of antipsychotics. 14 Iwata et al 15 recently reported that the overall EPS incidence with blonanserin transdermal patches is lower than that of blonanserin tablets.
Moreover, these authors suggested that the lower EPS incidence may be caused by more stable plasma blonanserin levels with the transdermal patch compared with oral formulations. 15 The increased plasma level stability with the patch formulation may be related to the direct absorption of blonanserin through the skin.
As the compound bypasses the gastrointestinal tract, no effects of food on bioavailability (as is the case with oral blonanserin) are observed. 16 Furthermore, the blonanserin patch provides continuous release of blonanserin, which may also contribute to stable plasma blonanserin levels. 9 It is therefore possible that, in the present patient, the stable blood levels made possible by the blonanserin patch resulted in both a favorable therapeutic effect and a reduction in side effects.
In summary, the present case report shows that switching from blonanserin tablets to blonanserin patches may reduce EPSs while maintaining a good therapeutic effect. By collecting data from more cases and studying the pharmacological properties of blonanserin patches, more appropriate treatments may be identified for schizophrenia patients. Although this treatment is currently only available in Japan, it is hoped that blonanserin patches will soon be available in additional countries.

| INFORMED CON S ENT
Informed consent was obtained from the participant.

ACK N OWLED G EM ENTS
We thank the patient and her family members for participating in this study. We also thank J. Ludovic Croxford, PhD, and Bronwen Gardner, PhD, from Edanz Group (https://en-autho r-servi ces.edanz. com/ac) for editing a draft of this manuscript.

CO N FLI C T O F I NTE R E S T
The authors declare no conflicts of interest associated with this article.

AUTH O R CO NTR I B UTI O N S
SS treated the patient and drafted the manuscript. Yo.M. critically reviewed the draft and revised it. All authors made substantial contributions, drafted the manuscript, and approved the final manuscript.

DATA AVA I L A B I L I T Y S TAT E M E N T
Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study.