The effect of food on the high clearance drug asenapine after sublingual administration to healthy male volunteers

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.

Asenapine: an atypical antipsychotic with atypical formulations

Asenapine is a second-generation (atypical) antipsychotic medication not available in a pill that can be swallowed; rather, it is commercialized in sublingual and transdermal formulations. This is a consequence of extensive first-pass metabolism if ingested. The sublingual formulation is approved in many jurisdictions for the treatment of schizophrenia and manic or mixed episodes associated with bipolar I disorder and is available generically. The efficacy profile is well characterized in a number of clinical trials, including an off-label use for the management of agitation. Obstacles to its use include food and drink restrictions, twice-daily dosing and adverse effects such as dysgeusia (distorted, altered, or unpleasant taste) and oral hypoesthesia (numbness). Transdermal asenapine was approved by the US Food and Drug Administration in 2019 for the treatment of schizophrenia in adults. Efficacy was established in a registrational study examining acutely ill inpatients with schizophrenia. The patch needs to changed once daily. Obstacles to its use include the potential for skin reactions such as erythema and pruritis, and being a branded product, it is more costly than other options. This is a narrative review of the chemistry and pharmacokinetics/pharmacodynamics of asenapine, as well as summarizing the efficacy and tolerability of both sublingual and transdermal asenapine, and its possible place in treatment.

Recent advances in the development of asenapine formulations

INTRODUCTION

Asenapine maleate (AM) is an atypical antipsychotic agent, that has been widely prescribed for the management of schizoaffective disorders. However, the bioavailability of AM is extremely poor due to the extensive first-pass metabolism. With the advancement in pharmaceutical technologies, significant strides have been made to create novel formulations to address the bioavailability problem of AM.

AREAS COVERED

This review article provides an insight into all the formulation approaches undertaken by researchers to increase the bioavailability of AM encompassing the works utilizing ultrasound mediated transdermal delivery, nose to brain delivery, intestinal lymphatic system targeting, in situ implants, etc. All the patents associated with AM formulation have also been discussed and summarized.

EXPERT OPINION

Numerous studies have been carried out on AM formulations over the recent years, many of these studies have shown significant improvement in bioavailability. We have also mentioned the unexplored domains which can be exploited for further enhancing the bioavailability of AM. Nonetheless, most of these studies are still limited to the research laboratory level and face multiple hurdles before making into the market. Attaining controllability and reproducibility for the production of novel formulations is needed to enable its transition from bench to bedside.

Efficacy and Safety of Asenapine Versus Olanzapine in Combination With Divalproex for Acute Mania: A Randomized Controlled Trial

BACKGROUND

Atypical antipsychotics are used for the treatment of acute mania, either as monotherapy or in combination with lithium or divalproex, which have a better tolerability profile as compared with typical antipsychotics. Asenapine, a newer atypical antipsychotic, has been found to be effective for the treatment of mania, with efficacy similar to olanzapine. The objective of the study was to compare the efficacy and safety of asenapine and olanzapine when used in combination with divalproex in patients with acute mania.

METHODS

One hundred twenty patients aged 18 to 55 years, diagnosed with manic episode, were randomized to receive either flexible dose of sublingual asenapine (10-20 mg/d) or tablet olanzapine (10-20 mg/d), in combination with valproate 20 mg/kg per day for a period of 6 weeks. Efficacy was measured as change in Young Mania Rating Scale and Clinical Global Impression-Bipolar using intention-to-treat analysis with last observation carried forward, and safety was measured using Udvalg for Kliniske Undersøgelser scale and Modified Simpson-Angus Extrapyramidal Side Effects Scale.

RESULTS

There was a significant reduction in Young Mania Rating Scale and Clinical Global Impression-Bipolar scores over time in both groups, with a significantly higher reduction in the olanzapine group as shown by the group × time interaction effect. Higher weight gain, increased sleep and appetite, and tremors were seen in the olanzapine-treated patients as compared with asenapine-treated patients; however, tongue hypesthesia was seen in the asenapine group only.

CONCLUSIONS

This study found that asenapine was an effective and well-tolerated atypical antipsychotic alternative to olanzapine in combination with divalproex for the short-term management of acute mania.

A Review of Asenapine in the Treatment of Bipolar Disorder

Bipolar disorder places a significant burden on the affected individuals, their family, healthcare systems and the overall economy. More treatment options are needed, especially those with better efficacy and tolerability. Asenapine is a second-generation antipsychotic approved in Europe (brand name Sycrest^®) for the treatment of moderate-to-severe manic episodes associated with bipolar I disorder in adults, and in the US (brand name Saphris^®) for the treatment of manic or mixed episodes of bipolar I disorder in adults and children aged 10-17 years. It is the antagonistic activity at the D₂ receptor that is likely responsible for the antimanic properties of asenapine. Clinical trials have demonstrated that asenapine mono- and add-on therapy is effective in the short- and long-term treatment of mania associated with bipolar I disorder in adult and paediatric patients. In addition, post hoc and pooled data analyses have shown that asenapine is effective in reducing clinically significant depressive symptoms in patients with bipolar I disorder. The most common adverse events associated with asenapine are somnolence, dizziness, extrapyramidal symptoms, increased bodyweight and oral hypoesthesia. However, the incidence of these events, particularly weight gain, is generally lower than with olanzapine. In one study, asenapine has been shown to improve health-related quality of life. Economic analyses indicate that the use of asenapine can, over time, lead to a reduction in the costs of treatment.

Asenapine Treatment in Pediatric Patients with Bipolar I Disorder or Schizophrenia: A Review

Asenapine, administered as a twice-daily (BID) sublingual tablet, is approved in the US as monotherapy for the acute treatment of manic and mixed episodes of bipolar I disorder in children and adolescents aged 10-17 years based on the positive results of one 3-week, double-blind, placebo-controlled study; the recommended dose is 2.5-10 mg BID. Although asenapine has been studied in pediatric patients with schizophrenia, it is not approved for this indication. Asenapine is not approved for pediatric use in bipolar I disorder or schizophrenia in other major markets. To inform clinicians treating psychiatric disorders in pediatric patients, we have summarized the neuropharmacology, pharmacokinetics, clinical trial experience, and clinical use of asenapine in pediatric patients. After rapid absorption through the oral mucosa, the pharmacokinetic profile of asenapine in pediatric patients is similar to that which is observed in adult patients, indicating that the recommended adult dosage does not need to be adjusted for pediatric use. Intake of food and water should be avoided for 10 min after administration. In clinical trials, asenapine was generally safe and well tolerated in pediatric patients with bipolar I disorder and schizophrenia. Serious adverse effects were generally related to worsening of the underlying psychiatric disorder. The most common treatment-emergent adverse events (TEAEs) in both indications were sedation and somnolence. Like some other second-generation antipsychotic agents, weight gain and changes in some metabolic parameters were noted; oral effects (e.g., oral hypoesthesia, dysgeusia, paresthesia) related to sublingual administration did not typically result in treatment discontinuation and were generally transient. Extrapyramidal symptom TEAEs occurred in ≥5% of asenapine-treated patients in the acute and long-term studies in bipolar I disorder and schizophrenia.