No pharmacokinetic interaction between paliperidone extended-release tablets and trimethoprim in healthy subjects

Comorbidities and the right dose: antipsychotics

INTRODUCTION

The effects of antipsychotic drugs are dose-dependent, which is particularly true for their efficacy, each antipsychotic having a specific dose-response curve. This may justify individualizing doses for these agents.

AREAS COVERED

We review the pharmacokinetic profiles of seven oral antipsychotics: haloperidol, risperidone, olanzapine, clozapine, quetiapine, ziprasidone, and aripiprazole. Their main indications are psychotic and affective disorders. They are prescribed in a very large population which may have comorbidities. Hence, we analyze the impact of the latter on the pharmacokinetic profiles of these antipsychotics, focusing on renal and hepatic impairment. Reviews and clinical trials were discussed based on a systematic literature search (PubMed) ranging from 1995 to 2022.

EXPERT OPINION

Factors liable to impact antipsychotic dosage are numerous and their subsequent effects often hard to predict, due to multi-level interactions and compensatory phenomena. In clinical practice, physicians must be aware of these potential effects, but base their decisions on monitoring antipsychotic plasma levels.

Clinically Relevant Interactions between Atypical Antipsychotics and Anti-Infective Agents

This is a comprehensive review of the literature on drug interactions (DIs) between atypical antipsychotics and anti-infective agents that focuses on those DIs with the potential to be clinically relevant and classifies them as pharmacokinetic (PK) or pharmacodynamic (PD) DIs. PubMed searches were conducted for each of the atypical antipsychotics and most commonly used anti-infective agents (13 atypical antipsychotics by 61 anti-infective agents/classes leading to 793 individual searches). Additional relevant articles were obtained from citations and from prior review articles written by the authors. Based on prior DI articles and our current understanding of PK and PD mechanism, we developed tables with practical recommendations for clinicians for: antibiotic DIs, antitubercular DIs, antifungal DIs, antiviral DIs, and other anti-infective DIs. Another table reflects that in clinical practice, DIs between atypical antipsychotics and anti-infective agents occur in patients also suffering an infection that may also influence the PK and PD mechanisms of both drugs (the atypical antipsychotic and the anti-infective agent(s)). These tables reflect the currently available literature and our current knowledge of the field and will need to be updated as new DI information becomes available.

Paliperidone Extended-Release Tablets for the Treatment of Methamphetamine Use Disorder in Chinese Patients After Acute Treatment: A Randomized, Double-Blind, Placebo-Controlled Exploratory Study

Background: To test paliperidone extended-release (ER) for efficacy in decreasing methamphetamine (METH) use and reducing psychotic symptoms in METH-dependent patients after detoxification. Rates of adverse events with paliperidone ER versus placebo were also compared. Methods: After discharge and 7 days without medication, 80 treatment-seeking METH-dependent participants were randomly assigned to paliperidone ER (3 mg once daily; n = 40) or placebo (once daily; n = 40) for 84 days under double-blind conditions. The participants attended clinics weekly to provide urine samples that were analyzed for METH metabolites, to complete research assessments, and to receive substance use and medication counseling. Results: Fifty-six percent of follow-up visits and final visits were completed. The placebo group had a significantly lower retention [51.5 days; 95% confidence interval (CI), 41.6-61.4] than the paliperidone ER group (69.4 days,; 95% CI, 61.9-76.9; p = 0.016). Paliperidone ER was a protective factor against psychotic symptom relapse [hazard ratio (HR) = 0.15, p = 0.003]. Moreover, there were statistically significant effects of paliperidone ER on psychosis severity and METH craving, assessed by mean changes in Positive and Negative Syndrome Scale (PANSS) total scores, Clinical Global Impression-Severity (CGI-S) scores, and METH craving scores over time (p = 0.006, p = 0.002, and p = 0.03 for the medication-by-time interaction effect, respectively). There were no statistically significant differences between the two groups in METH use. There were no serious adverse events related to the study drug. Conclusion: Compared with placebo, paliperidone ER administration resulted in a better retention rate and lower psychotic symptom relapse, but we did not find significantly reduced METH use among adults after acute METH detoxification treatment.

Clinically significant drug interactions with atypical antipsychotics

Atypical antipsychotics [also known as second-generation antipsychotics (SGAs)] have become a mainstay therapeutic treatment intervention for patients with schizophrenia, bipolar disorders and other psychotic conditions. These agents are commonly used with other medications--most notably, antidepressants and antiepileptic drugs. Drug interactions can take place by various pharmacokinetic, pharmacodynamic and pharmaceutical mechanisms. The pharmacokinetic profile of each SGA, especially with phase I and phase II metabolism, can allow for potentially significant drug interactions. Pharmacodynamic interactions arise when agents have comparable receptor site activity, which can lead to additive or competitive effects without alterations in measured plasma drug concentrations. Additionally, the role of drug transporters in drug interactions continues to evolve and may effect both pharmacokinetic and pharmacodynamic interactions. Pharmaceutical interactions occur when physical incompatibilities take place between agents prior to drug absorption. Approximate therapeutic plasma concentration ranges have been suggested for a number of SGAs. Drug interactions that markedly increase or decrease the concentrations of these agents beyond their ranges can lead to adverse events or diminished clinical efficacy. Most clinically significant drug interactions with SGAs occur via the cytochrome P450 (CYP) system. Many but not all drug interactions with SGAs are identified during drug discovery and pre-clinical development by employing a series of standardized in vitro and in vivo studies with known CYP inducers and inhibitors. Later therapeutic drug monitoring programmes, clinical studies and case reports offer methods to identify additional clinically significant drug interactions. Some commonly co-administered drugs with a significant potential for drug-drug interactions with selected SGAs include some SSRIs. Antiepileptic mood stabilizers such as carbamazepine and valproate, as well as other antiepileptic drugs such as phenobarbital and phenytoin, may decrease plasma SGA concentrations. Some anti-infective agents such as protease inhibitors and fluoroquinolones are of concern as well. Two additional important factors that influence drug interactions with SGAs are dose and time dependence. Smoking is very common among psychiatric patients and can induce CYP1A2 enzymes, thereby lowering expected plasma levels of certain SGAs. It is recommended that ziprasidone and lurasidone are taken with food to promote drug absorption, otherwise their bioavailability can be reduced. Clinicians must be aware of the variety of factors that can increase the likelihood of clinically significant drug interactions with SGAs, and must carefully monitor patients to maximize treatment efficacy while minimizing adverse events.

Pharmacological and clinical profile of recently approved second-generation antipsychotics: implications for treatment of schizophrenia in older patients

Antipsychotics are frequently used in elderly patients to treat a variety of conditions, including schizophrenia. While extensively studied for their impact in younger populations, there is comparatively limited evidence about the effectiveness of these agents in older patients. Further complicating this situation are the high comorbidity rates (both psychiatric and medical) in the elderly; age-related changes in pharmacokinetics that lead to a heightened proclivity for adverse effects; and the potential for multiple, clinically relevant drug interactions. With this background in mind, we review diagnostic and treatment-related issues specific to elderly patients suffering from schizophrenia. We then focus on the potential role of the most recently approved second-generation antipsychotics, paliperidone (both the extended-release oral formulation and the long-acting injectable formulation), iloperidone, asenapine and lurasidone, given the limited clinical experience with these agents in the elderly. While there is limited data to support their safety, tolerability and efficacy in older patients with schizophrenia, each has unique characteristics that should be considered when used in this population.

Role of organic cation transporter OCT2 and multidrug and toxin extrusion proteins MATE1 and MATE2-K for transport and drug interactions of the antiviral lamivudine

The antiviral lamivudine is cleared predominantly by the kidney with a relevant contribution of renal tubular secretion. It is not clear which drug transporters mediate lamivudine renal secretion. Our aim was to investigate lamivudine as substrate of the renal drug transporters organic cation transporter 2 (OCT2) and multidrug and toxin extrusion proteins MATE1 and MATE2-K. Uptake experiments were performed in OCT2, MATE1, or MATE2-K single-transfected human embryonic kidney 293 (HEK) cells. Transcellular transport experiments were performed in OCT2 and/or MATE1 single- or double-transfected Madin-Darby canine kidney II (MDCK) cells grown on transwell filters. Lamivudine uptake was significantly increased in HEK-OCT2, HEK-MATE1, and HEK-MATE2-K cells compared to control cells. In transcellular experiments, OCT2 located in the basolateral membrane had no effect on transcellular lamivudine transport. MATE1 located in the apical membrane decreased intracellular concentrations and increased transcellular transport of lamivudine from the basal to the apical compartment. MATE1- or MATE2-K-mediated transport was increased by an oppositely directed pH gradient. Several simultaneously administered drugs inhibited OCT2- or MATE2-K-mediated lamivudine uptake. The strongest inhibitors were carvedilol for OCT2 and trimethoprim for MATE2-K (inhibition by 96.3 and 83.7% at 15 μM, respectively, p<0.001). Trimethoprim inhibited OCT2- and MATE2-K-mediated lamivudine uptake with IC₅₀ values of 13.2 and 0.66 μM, respectively. Transcellular lamivudine transport in OCT2-MATE1 double-transfected cells was inhibited by trimethoprim with an IC₅₀ value of 6.9 μM. Lamivudine is a substrate of renal drug transporters OCT2, MATE1, and MATE2-K. Concomitant administration of drugs that inhibit these transporters could decrease renal clearance of lamivudine.

Paliperidone extended release: in adolescents with schizophrenia

Paliperidone, the major active metabolite of risperidone, is an atypical antipsychotic agent formulated as an extended-release (ER) tablet suitable for once-daily oral administration. Paliperidone ER is approved for the treatment of adolescents aged 12-17 years with schizophrenia in the US (the focus of this review). It is also approved for the treatment of adults with schizophrenia or schizoaffective disorder. Paliperidone ER has shown efficacy in the treatment of patients aged 12-17 years with acutely symptomatic schizophrenia in a randomized, double-blind, parallel-group, placebo-controlled, multicenter, 6-week trial. The primary endpoint was the change from baseline in Positive and Negative Syndrome Scale (PANSS) total score to day 43 or the final assessment point post-baseline. Patients with a PANSS total score of 60-120 received one of three weight-based, fixed once-daily doses of paliperidone ER (patients weighing 29 kg to <51 kg: 1.5 mg [low-dose], 3 mg [medium], or 6 mg [high]; patients weighing ≥51 kg: 1.5 mg [low], 6 mg [medium], or 12 mg [high]), or placebo. Compared with placebo, significant improvements in mean PANSS total scores were reported for the medium-dose (3-6 mg) paliperidone ER treatment groups. There were no significant differences in mean PANSS total scores between the recipients of low-dose or high-dose paliperidone ER versus placebo. Mean PANSS total scores in the actual dose treatment groups (regardless of weight) decreased from baseline (i.e. improved) and were significantly lower for the 3, 6, and 12 mg groups than for the placebo group. Treatment-emergent adverse events were dose related in adolescents with schizophrenia who received weight-based fixed doses of paliperidone ER.

Paliperidone: a review of clinical trial data and clinical implications

Paliperidone, 9-hydroxy-risperidone, is the major metabolite of the atypical antipsychotic risperidone and is available in an oral extended-release (ER) formulation. Paliperidone ER was approved for treating schizophrenia in 2006, and in 2009 it became the first atypical antipsychotic licensed for treating schizoaffective disorder. The short-term efficacy, safety and tolerability of paliperidone ER for patients with schizophrenia were demonstrated in three pivotal 6-week, randomized, double-blind, placebo-controlled studies. Data from the long-term trial showed that paliperidone ER is also effective in preventing relapse of schizophrenia. Two randomized, placebo-controlled, short-term studies have documented the efficacy and tolerability of paliperidone ER in the treatment of schizoaffective disorder, but no long-term or maintenance study has been conducted in patients with schizoaffective disorder. Two 3-week, randomized, double-blind, placebo-controlled studies showed that paliperidone ER is significantly superior to placebo for treating patients with bipolar disorder, but the results were driven by certain subpopulations. Limited evidence suggests that paliperidone ER can potentially be superior to quetiapine and risperidone. However, few direct head-to-head comparisons between paliperidone ER and other antipsychotics have been conducted to confirm these results. The distinctive pharmacological characteristics of paliperidone ER, including smooth fluctuations in plasma drug concentrations, predominantly renal excretion, low risk of causing hepatic impairment and low drug-drug interaction, might provide important clinical advantages compared with risperidone. However, certain side effects require clinical attention. The rate of extrapyramidal side effects was considerably higher than that of a placebo at doses ≥9 mg/day. The risks for orthostatic hypotension, prolongation of the corrected QT interval and hyperprolactinaemia are also concerns. This review summarizes the currently published data on paliperidone ER for treating patients with schizophrenia, schizoaffective disorder and bipolar disorder, and suggests its appropriate use in clinical practice.

Inhibitory metabolic drug interactions with newer psychotropic drugs: inclusion in package inserts and influences of concurrence in drug interaction screening software

BACKGROUND

Food and Drug Administration (FDA) regulations mandate that package inserts (PIs) include observed or predicted clinically significant drug-drug interactions (DDIs), as well as the results of pharmacokinetic studies that establish the absence of effect.

OBJECTIVE

To quantify how frequently observed metabolic inhibition DDIs affecting US-marketed psychotropics are present in FDA-approved PIs and what influence the source of DDI information has on agreement between 3 DDI screening programs.

METHODS

The scientific literature and PIs were reviewed to determine all drug pairs for which there was rigorous evidence of a metabolic inhibition interaction or noninteraction. The DDIs were tabulated noting the source of evidence and the strength of agreement over chance. Descriptive statistics were used to examine the influence of source of DDI information on agreement among 3 DDI screening tools. Logistic regression was used to assess the influence of drug class, indication, generic status, regulatory approval date, and magnitude of effect on agreement between the literature and PI as well as agreement among the DDI screening tools.

RESULTS

Thirty percent (13/44) of the metabolic inhibition DDIs affecting newer psychotropics were not mentioned in PIs. Drug class, indication, regulatory approval date, generic status, or magnitude of effect did not appear to be associated with more complete DDI information in PIs. DDIs found exclusively in PIs were 3.25 times more likely to be agreed upon by all 3 DDI screening tools than were those found exclusively in the literature. Generic status was inversely associated with agreement among the DDI screening tools (odds ratio 0.11; 95% CI 0.01 to 0.89).

CONCLUSIONS

The presence in PIs of DDI information for newer psychotropics appears to have a strong influence on agreement among DDI screening tools. Users of DDI screening software should consult more than 1 source when considering interactions involving generic psychotropics.

The role of paliperidone extended release for the treatment of bipolar disorder

BACKGROUND

Bipolar disorder (BD) is a chronic, relapsing, episodic mental illness associated with other psychiatric comorbidities. There is a substantial economic burden with BD, which makes it challenging to treat. The aim of this review is to evaluate the pharmacology, clinical efficacy, and safety data related to paliperidone extended release (ER) for the treatment of BD.

METHODS

A literature search was performed from January 1966 through January 2012 using PreMEDLINE, MEDLINE, EMBASE, IPA, and ClinicalTrials.gov to identify articles in English regarding the pharmacology, clinical efficacy, and safety of paliperidone ER in acute mania or mixed episodes or in the maintenance treatment of BD I.

RESULTS

There are currently three published studies relating to the use of paliperidone ER for the treatment of BD. Two of these evaluated paliperidone ER as monotherapy for acute mania, while the other assessed its role as adjunct with a mood stabilizer.

CONCLUSION

According to the limited available evidence, paliperidone at higher doses of ER 9-12 mg/day may be a safe and efficacious treatment option for acute episodes of mania in BD. A once-daily dose formulation may improve patient adherence to treatment; however, the cost of paliperidone ER, which is higher than that of generically available second-generation antipsychotics (such as olanzapine and risperidone), and a lack of alternative dosage forms (ie, liquid, intramuscular) compared with other agents may limit its usefulness in the treatment of BD. The role of paliperidone ER as an adjunctive agent or for long-term use requires further investigation.

Oral paliperidone: a review of its use in the management of schizoaffective disorder

Oral paliperidone extended or prolonged release (Invega®) is an atypical antipsychotic, and is the first agent approved for the treatment of schizoaffective disorder. Paliperidone (or 9-hydroxyrisperidone) is the major active metabolite of the well known atypical antipsychotic risperidone, and its mechanism of action is thought to be the antagonism of dopamine D(2) and serotonin 5-HT(2A) receptors. The clinical efficacy of paliperidone was demonstrated in two 6-week, randomized, double-blind, placebo-controlled, multicentre trials in patients with schizoaffective disorder. One trial was flexible dose in design (3-12 mg/day) and the other was fixed dose in design (3-6 and 9-12 mg/day). Compared with placebo, the change from baseline at study end in the Positive and Negative Syndrome Scale (PANSS) total score (primary endpoint) was significantly greater with paliperidone 3-12 mg/day in one trial and with 9-12 mg/day (but not 3-6 mg/day) in the other trial. However, pooled analyses reported a significantly greater change in PANSS total score across all paliperidone dosages than with placebo. Paliperidone was generally well tolerated in the 6-week trials, and no unexpected adverse events were reported. The most commonly reported treatment-emergent adverse events were headache, tremor, dizziness, insomnia, nausea, akathisia, dyspepsia, hypertonia, somnolence and sedation. Although long-term efficacy and tolerability data and comparisons with other antipsychotics are needed, paliperidone appears to be a useful agent for the short-term management of patients with schizoaffective disorder.

Paliperidone extended-release: does it have a place in antipsychotic therapy?

Paliperidone (9-hydroxy-risperidone), the active metabolite of risperidone, was approved for treating schizophrenia worldwide in 2006 as paliperidone extended-release (PER), and became the first second-generation antipsychotic specifically licensed for treating schizoaffective disorder in 2009. However, at the same time, its comparatively high cost gave rise to concerns about the cost-effectiveness of PER as compared with its precursor, risperidone. This paper reviews the existing knowledge of the pharmacology, kinetics, efficacy, tolerability, and fields of application of PER, and compares PER with risperidone in order to determine whether it has a place in antipsychotic therapy. An independent assessment of all relevant publications on PER published until July 2010 was undertaken. PER has a unique pharmacological profile, including single dosing, predominantly renal excretion, low drug-drug interaction risk, and differs from risperidone in terms of mode of action and pharmacokinetics. High-level evidence suggests that PER is efficacious and safe in schizophrenia, schizoaffective disorder, and acute manic episodes. There is a striking lack of published head-to-head comparisons between PER and risperidone, irrespective of indication. Low-level evidence shows a lower risk for hyperprolactinemia and higher patient satisfaction with PER than with risperidone. PER adds to the still limited arsenal of second-generation antipsychotics. In the absence of direct comparisons with risperidone, it remains difficult to come to a final verdict on the potential additional therapeutic benefits of PER which would justify its substantially higher costs as compared with risperidone. However, in terms of pharmacology, the available evidence cautiously suggests a place for PER in modern antipsychotic therapy.

Safety and efficacy of paliperidone extended-release in acute and maintenance treatment of schizophrenia

Paliperidone, the major active metabolite of risperidone, is a second-generation antipsychotic that has been developed as an extended-release (ER) tablet formulation that minimizes peak-trough fluctuations in plasma concentrations, allowing once-daily administration and constant drug delivery. Paliperidone ER has demonstrated efficacy in the reduction of acute schizophrenia symptoms in 6-week, placebo-controlled, double-blind trials and clinical benefits were maintained in the longer-term according to extension studies of up to 52 weeks in duration. Compared with quetiapine, paliperidone ER was associated with a more rapid symptom improvement. In addition, it was more effective than placebo in the prevention of symptom recurrence. Paliperidone ER is generally well tolerated with a predictable adverse event profile. Like risperidone, it is associated with a dose-dependent risk of extrapyramidal symptoms and prolactin elevation. Short- and longer-term studies have indicated a low liability for paliperidone ER to cause metabolic (ie, weight gain, hyperglycaemia and lipid dysregulation) or cardiovascular adverse effects. Available safety data from elderly patients appear to be promising. Due to negligible hepatic biotransformation, paliperidone ER is unlikely to be involved in clinically significant metabolic drug-drug interactions. Additional active comparator trials evaluating efficacy, tolerability and cost-effectiveness are required to better define the role of paliperidone ER in the treatment of schizophrenia in relation to other currently available second-generation antipsychotics, particularly risperidone.

Practical guidance for dosing and switching paliperidone palmitate treatment in patients with schizophrenia

OBJECTIVE

This article overviews the recommended dosing strategies for the treatment of schizophrenia patients using the recently FDA-approved once-monthly long-acting injectable atypical antipsychotic, paliperidone palmitate.

METHODS

Using pharmacokinetic (PK), efficacy and safety data from clinical trials and a comprehensive population PK simulation model, dosing recommendations for paliperidone palmitate have been generated.

RESULTS

The recommended initiation regimen is 150 mg eq. paliperidone palmitate (234 mg) on Day 1 followed by 100 mg eq. paliperidone palmitate (156 mg) on Day 8, each administered into the deltoid muscle, using a 1-inch 23 gauge (G) needle in those <90 kg and a 1.5-inch 22 G needle in those > or =90 kg. No oral supplementation is required. Monthly maintenance doses of paliperidone palmitate range from 25-150 mg eq. (39-234 mg; recommended dose of 75 mg eq. [117 mg]) injected into the deltoid (using weight-adjusted needle) or gluteal (using 1.5 inch 22 G needle) muscle. The Day 8 dose may be administered +/-2 days and monthly doses +/-7 days, without a clinically significant impact on plasma concentrations. In patients with mild renal impairment (creatinine clearance [CrCL]: 50-80 mL/min), dosage should be adjusted. No dose adjustment is required in patients with mild or moderate hepatic impairment; no data currently exist regarding severe hepatic impairment. Elderly patients with normal renal function should receive the same dosage as younger adult patients with normal renal function. In the event of an age-related decline in CrCL, dosage should be adjusted accordingly. Paliperidone palmitate treatment can be initiated the day after discontinuing previous oral antipsychotic treatment. Paliperidone palmitate should be initiated at the next scheduled injection, and monthly thereafter, in patients switching from other long-acting injectable antipsychotics, including long-acting risperidone.

CONCLUSIONS

These data provide practical guidance to clinicians on how to use paliperidone palmitate in adult patients with schizophrenia.