The pharmacology and safety of paliperidone extended-release in the treatment of schizophrenia

A Comprehensive Review on Importance and Quantitation of Atypical Antipsychotic Drugs and their Active Metabolites in Commercial Dosage Forms

Background:

Schizophrenia is a severe mental illness that affects more than twenty-one million people throughout the world. Schizophrenia also causes early death. Schizophrenia and other related psychotic ailments are controlled by the prescription of antipsychotic drugs, which act by blocking certain chemical receptors in the brain and thus relieves the symptoms of psychotic disorder. These drugs are present in the different dosage forms in the market and provided in a certain amount as per the need of the patients.

Objective:

Since such medications treat mental disorders, it is very important to have a perfect and accurate dose so that the risk factor is not affected by a higher or lower dose, which is not sufficient for the treatment. For accurate assay of these kinds of drugs, different analytical methods were developed ranging from older spectrophotometric techniques to latest hyphenated methods.

Results:

The current review highlights the role of different analytical techniques that were employed in the determination and identification of antipsychotic drugs and their metabolites. Techniques such as spectrophotometry, fluorimetry, liquid chromatography, liquid chromatography-mass spectrometry, gas chromatography, and gas chromatography-mass spectrometry employed in the method development of such antipsychotic drugs were reported in the review. Different metabolites, identified using the hyphenated techniques, were also mentioned in the review. The synthesis pathways of few of the metabolites were mentioned.

Conclusion:

The review summarizes the analyses of different antipsychotic drugs and their metabolites. A brief introduction of illnesses and their symptoms and possible medications were highlighted. Synthesis pathways of the associated metabolites were also mentioned.

Paliperidone, a relatively novel atypical antipsychotic drug, is a substrate for breast cancer resistance protein

Paliperidone (PAL) is a relatively novel atypical antipsychotic drug for schizophrenia that induces markedly varying responses. Breast cancer resistance protein (BCRP) is a recently discovered member of the ATP-binding cassette superfamily that has been used to control drug absorption, distribution and elimination, and especially to impede drug entry into the brain. To the best of our knowledge, the present study is the first to investigate the possibility of using PAL as a BCRP substrate. The intracellular accumulation and bidirectional transport were investigated using transfected 293 cell/BCRP and porcine renal endothelial cell (LLC-PK1)/BCRP cell monolayers and BCRP overexpression was confirmed by reverse transcription-quantitative polymerase chain reaction and western blot analysis. The in vitro affinity to BCRP was assessed in human BCRP (Arg482) membranes. The intracellular accumulation and bidirectional transport investigations demonstrated that BCRP can efflux PAL from cells and significantly decrease its cellular concentration over a concentration range of 0.1-50 µM. The in vitro affinity experiments indicated that PAL has a moderate affinity to BCRP at 0.1-100 µM. These results together suggest that PAL is a substrate for BCRP and that it can affect the blood-brain barrier penetration of PAL at therapeutic dosages.

Paliperidone for the treatment of schizophrenia and schizoaffective disorders - a drug safety evaluation

INTRODUCTION

Paliperidone, the major active metabolite of risperidone, is a second-generation antipsychotic that has been developed as an extended-release (ER) oral formulation and a long-acting injectable paliperidone palmitate (PP) formulation. Paliperidone has demonstrated efficacy in the reduction of acute schizophrenia symptoms and clinical benefits were maintained also in the long-term treatments. Paliperidone ER and PP are generally well tolerated with a predictable adverse event profile. Areas covered: Data from studies evaluating safety and tolerability in the acute and maintenance treatment of schizophrenia with paliperidone are reviewed. The reported treatment-emergent adverse events of these formulations are discussed. Expert opinion: In the treatment of schizophrenia and schizoaffective disorders the safety profile has a central role because it can enhance patient compliance. In fact treatment-emergent adverse events are one of the main causes of discontinuation in these patients. In particular the main limitation in the administration of paliperidone could be represented by the onset of hyperprolactinemia (especially in women) and of mild parkinsonism. Paliperidone has a high impact on current long-term drug strategies, especially given the new 3 month long-acting injectable formulation of PP.

Paliperidone regulates intracellular redox system in rat brain: Role of purine mechanism

OBJECTIVE

The treatment of schizophrenia is multifactorial, with antipsychotic medications comprising a major part of treatment. Paliperidone is a newly commercialized antipsychotic whose formulation includes the principal active metabolite risperidone, 9-hydroxyrisperidone. Ever since the relationship between schizophrenia and oxidative stress was first demonstrated, many studies have been conducted in order to probe the potential protective effects of antipsychotic drugs on the oxidant-antioxidant system and lipid peroxidation. The basic aim of this study is to determine the effects of the newly marketed drug paliperidone on the activities of the enzymes adenosine deaminase (ADA), xanthine oxidase (XO), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) as well as on malondialdehyde (MDA) and nitric oxide (NO) levels in rat brain tissues.

METHODS

Twenty male Sprague-Dawley rats were used for the study, which were divided into two equal groups. The first was the control group (n = 10) and the second was the paliperidone group (n = 10). Saline was administered once daily for 14 days in the control group. In the paliperidone group, paliperidone was administered once daily with a dose of 1 mg/kg for 14 days. All rats were sacrificed at the end of the fourteenth day. Brain samples were collected and then analyzed.

RESULTS

Our results demonstrated that paliperidone significantly decreased the activities of ADA (P = 0.015), XO (P = 0.0001), and CAT (P = 0.004) while insignificantly increasing the activity of SOD (P = 0.49), MDA (P = 0.71), and NO (P = 0.26) levels in rat brain tissues. In addition, paliperidone insignificantly decreased the activity of GSH-Px (P = 0.30) compared to the control group in rat brain tissues.

DISCUSSION

In conclusion, the data obtained in this study suggest that paliperidone can positively alter antioxidant status and, accordingly, can offer positive outcomes in the treatment of schizophrenia by reducing activity in the enzymes ADA and XO, which are associated with purine metabolism. We believe that such a comprehensive approach used with other antipsychotic drugs warrants further study.

A retrospective observational study of the effectiveness of paliperidone palmitate on acute inpatient hospitalization rates

This retrospective mirror-image observational study aimed to establish the effects of the long-acting antipsychotic injection paliperidone palmitate (PP) on acute inpatient hospitalization rates. We utilized routinely collected clinical data to compare the number and length of acute patient admissions 1 year before and 1 year after initiation of PP. A single cohort of 66 patients with a diagnosis of schizophrenia and who had received monthly injections of PP for at least 1 year were included in the analysis. The mean number of acute inpatient admissions fell from 0.86 in the year before PP initiation to 0.23 in the following year (P = 0.001), and there was a numerical but nonsignificant decrease in the number of bed days from 32.48 to 31.22 over the study duration. The median number of bed days in the year before PP initiation was 20, and in the year after initiation it was 0. The median number of admissions also fell from 1 to 0 during the same period. The results of the study should be treated cautiously because of the limitations of the study design but suggest that patients with a diagnosis of schizophrenia who continue treatment with PP over 12 months experience a significant reduction in hospital admissions compared with the previous year.

Efficacy and safety of sertindole in schizophrenia: a clinical review

Sertindole is an atypical antipsychotic reintroduced into the European market in 2005 after a reevaluation of its risks and benefits, under the agreement that close electrocardiographic screening would be conducted. It has a high affinity for dopamine D2, serotonin 5-HT2A and 5-HT2C, and α1 adrenergic receptors. Moreover, sertindole shows modest affinity for H1-histaminergic and muscarinic receptors. The pharmacological properties, clinical efficacy, safety, and tolerability of sertindole are covered in this article based on a literature review from 1990 to 2014. Given current available findings, sertindole is at least effective as haloperidol, risperidone, and olanzapine on schizophrenia symptoms. Regarding its efficacy on cognitive symptoms, sertindole effect is supported by both preclinical and clinical studies versus haloperidol and olanzapine; however, its role on cognition needs further clarification. Concerning safety and tolerability issues, sertindole is characterized by a low potential to cause sedation and extrapyramidal symptoms, and by an acceptable metabolic profile; nevertheless, cardiac safety remains a major concern, and the electrocardiographic monitoring should be carried out during treatment to substantially reduce cardiovascular risk. In conclusion, although it has an equivalent profile compared to other antipsychotic drugs, sertindole actually remains a second-line choice for schizophrenic patients intolerant to at least one other antipsychotic agent.

A review of paliperidone palmitate

Risperidone long-acting injection (RLAI) was the first second-generation antipsychotic available as a long-acting injection. Paliperidone (9-hydroxyrisperidone) is the active metabolite of risperidone, introduced initially as an extended release oral (ORal Osmotic System, OROS®, Alza Corporation) formulation (Invega®, Janssen). Paliperidone long-acting injection (PLAI) has now been developed as a suspension of paliperidone palmitate nanocrystals in an aqueous formulation (Invega Sustenna®, Xeplion®), administered monthly by intramuscular injection (deltoid or gluteal). Doses of PLAI can be expressed either in milligram equivalents (mg eq) of paliperidone palmitate or in milligrams of the active fraction of paliperidone. The recommended initiation regimen of 150 mg eq (234 mg) on day 1 and 100 mg eq (156 mg) on day 8 (both administered in the deltoid) achieves therapeutic blood levels rapidly and without the necessity of oral supplementation. No refrigeration or reconstitution prior to administration is required. PLAI has been shown in to be effective in controlling the acute symptoms of schizophrenia as well as delaying time to relapse. Safety and tolerability are comparable to RLAI with no new safety signals. Thus, PLAI may represent the rational development of RLAI with greater ease of use.

Efficacy and metabolic influence of paliperidone ER, aripiprazole and ziprasidone to patients with first-episode schizophrenia through 52 weeks follow-up in China

BACKGROUND

There are no direct comparisons of paliperidone extended-release (ER), aripiprazole and ziprasidone in efficacy and metabolic influence in patients with first-episode schizophrenia.

OBJECTIVE

The present study examined the efficacy and metabolic influence of paliperidone ER, aripiprazole and ziprasidone in patients with first-episode schizophrenia in China.

METHODS

Subjects were recruited from outpatient and 254 patients entered the trial. These patients received treatment randomly with paliperidone ER, aripiprazole and ziprasidone and were assessed at baseline, 13, 26 and 52 weeks, respectively with Positive and Negative Syndrome Scale (PANSS), 7-item Clinical Global Impressions-Severity (CGI-S), anthropometric (weight, body mass index and waist circumference) and metabolic (fasting blood glucose, HbA1c, cholesterol, high density lipoproteins (HDL), low density lipoproteins and triglycerides) measures.

RESULTS

A total of 203 patients completed the trial. Paliperidone group had significant greater reduction in PANSS than aripiprazole group and ziprasidone group from 13 weeks, although the a reduction in PANSS of each group was more than 20%. There was no difference in CGI-S among the three groups, and all three groups had a significant reduction from baseline in CGI-S. Aripiprazole group increased in weight and body mass index despite no statistical change in waist circumference. Other two groups showed no changes in anthropometric measure. At the end of the study, two glucose metabolic indices (fasting blood glucose and HbA1c) of aripiprazole group were significantly higher than that of baseline. In lipid metabolism, aripiprazole group reduced triglycerides significantly and had no changes in other indices. Paliperidone group reduced HDL and increased triglycerides despite no changes in glucose metabolism. Ziprasidone group also had no significant changes in glucose metabolism, but reduced cholesterol, low density lipoproteins and increased HDL. Furthermore, 22 subjects in three groups reached the diagnostic criteria of metabolic syndrome.

CONCLUSIONS

Paliperidone ER, aripiprazole and ziprasidone are effective in treating first-episode schizophrenia, and the ranking of efficacy from high to low is paliperidone ER > aripiprazole > ziprasidone. Paliperidone ER can impair lipid metabolism potentially but had no influence on glucose metabolism. Aripiprazole can damage glucose metabolism and has little influence on lipid metabolism. Ziprasidone is considered an atypical antipsychotic with no evidence of harm to glucose and lipid metabolism.

A randomized trial of paliperidone palmitate and risperidone long-acting injectable in schizophrenia

Paliperidone palmitate (PP) is a recently (USA) approved injectable new-generation antipsychotic. This 53-wk, Phase-III double-blind study was designed to assess the non-inferiority of PP to risperidone long-acting injectable (RIS-LAI) in schizophrenia treatment. Acutely symptomatic patients (n=749), with a Positive and Negative Syndrome Scale (PANSS) total score between 60 and 120 were randomly allocated to gluteal injections of either (a) PP: 50 mg eq. on days 1 and 8, and flexible dosing [25-100 mg eq. (i.e. 39-156 mg USA dosing)] once-monthly; or (b) RIS-LAI: bi-weekly injections of 25 mg on days 8 and 22, and flexible dosing (25-50 mg) starting from day 36, with allowed oral supplementation. Patients (n=747) were 59% men, 92% white, mean (s.d.) age of 41 (11.95) yr and 45% (n=339) completed the study. Mean (s.d.) change from baseline to endpoint in PANSS total score was: -11.6 (21.22) PP; and -14.4 (19.76) RIS-LAI (per-protocol analysis set, primary measure); least-squares means difference was -2.6 (95% CI -5.84 to 0.61), with a prespecified 5-point non-inferiority margin. PP's suboptimal dosing regimen (<150 mg eq. initial dose) resulted in lower median plasma levels of the active moiety in PP-treated vs. RIS-LAI-treated patients. Insomnia was the most common treatment-emergent adverse event, with a similar incidence in both groups (15%). PP did not demonstrate comparable efficacy to RIS-LAI, which may be attributable to the initiation dosing strategy employed. Tolerability of both treatments was comparable to previous studies, with no new safety signals detected.

Paliperidone ER in the Treatment of Borderline Personality Disorder: A Pilot Study of Efficacy and Tolerability

Antipsychotics are recommended for the treatment of impulsive dyscontrol and cognitive perceptual symptoms of borderline personality disorder (BPD). Three reports supported the efficacy of oral risperidone on BPD psychopathology. Paliperidone ER is the metabolite of risperidone with a similar mechanism of action, and its osmotic release reduces plasmatic fluctuations and antidopaminergic effects. The aim of this study is to evaluate efficacy and safety of paliperidone ER in BPD patients. 18 outpatients with a DSM-IV-TR diagnosis of BPD were treated for 12 weeks with paliperidone ER (3-6 mg/day). They were assessed at baseline, week 4, and week 12, using the CGI-Severity item, the BPRS, the HDRS, the HARS, the SOFAS, the BPD Severity Index (BPDSI), and the Barratt Impulsiveness Scale (BIS-11). Adverse events were evaluated with the DOTES. Paliperidone ER was shown to be effective and well tolerated in reducing severity of global symptomatology and specific BPD symptoms, such as impulsive dyscontrol, anger, and cognitive-perceptual disturbances. Results need to be replicated in controlled trials.

Obesity and psychotropics

Weight gain is on the rise in the United States as is the diagnosis and treatment of mental disorders. These two phenomena are distinctly separate but tend to overlap in that most psychotropic agents approved for use in the United States are associated with the potential to induce weight gain. Metabolic disorders such as diabetes, hypercholesterolemia, and hypertension are also on the rise and often associated with weight gain and clearly associated with certain psychotropic medications. This article serves to provide a succinct review regarding the epidemiology, etiology, and treatment options for psychotropic-induced obesity.

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.

Weight gain, obesity, and psychotropic prescribing

A majority of psychiatric medications are known to generate weight gain and ultimately obesity in some patients. There is much speculation about the prevalence of weight gain and the degree of weight gain during acute and longitudinal treatment with these agents. There is newer literature looking at the etiology of this weight gain and the potential treatments being used to alleviate this side effect. The authors undertook a comprehensive literature review in order to present epidemiology, etiology, and treatment options of weight gain associated with antipsychotics, mood stabilizers, and antidepressants.

Metformin for atypical antipsychotic-induced weight gain and glucose metabolism dysregulation: review of the literature and clinical suggestions

Individuals receiving certain atypical antipsychotic medications are at risk of gaining weight and developing metabolic problems. There are no established drug treatments to prevent or counter these problems. However, the antihyperglycaemic agent metformin appears promising in some recent studies and we review the literature that evaluates metformin for limiting or reversing atypical antipsychotic drug-induced weight gain and glucose metabolism dysregulation. These studies suggest that metformin is beneficial if started early in antipsychotic drug treatment. Metformin has also been shown to prevent or delay the onset of type 2 diabetes mellitus in high-risk individuals from the general population. Based on these findings, we identify antipsychotic drug-treated patients who might benefit from metformin therapy and offer clinical guidelines for its use. Further long-term studies are needed to extend our observations and improve this strategy.

Paliperidone palmitate - review of the efficacy, safety and cost of a new second-generation depot antipsychotic medication

OBJECTIVE

To describe the efficacy, safety and cost of paliperidone palmitate, a depot antipsychotic medication recently approved for the treatment of schizophrenia.

DATA SOURCES

A literature search was conducted by querying the websites http://www.pubmed.gov, http://www.fda.gov, http://www.accessdata.fda.gov/scripts/cder/drugsatfda and http://www.clinicaltrials.gov for the search term 'paliperidone palmitate'. Cost information was obtained from the pharmaceutical vendor servicing a local state-operated psychiatric facility.

STUDY SELECTION

All available reports of studies were identified. Product labelling provided additional information.

DATA EXTRACTION

Descriptions of the principal results and calculation of the number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the study reports and synopses. Additional safety outcomes subject to NNH analysis were obtained from product labelling.

DATA SYNTHESIS

Paliperidone palmitate is a newly available depot formulation of paliperidone (the 9-OH metabolite of risperidone). Upon injection into the deltoid or gluteal muscle, the release of the drug starts as early as day 1, reaches maximum plasma concentrations at 13 days and lasts for as long as 126 days. Maximum concentration following deltoid injection is approximately 28% higher compared with injection into the gluteal muscle, and thus paliperidone palmitate requires initiation by two initial deltoid injections spread 1 week apart to achieve therapeutic concentrations rapidly. Subsequent injections are at 4-week intervals. Acute efficacy was evidenced by four short-term double-blind, randomised, placebo-controlled, fixed-dose studies of acutely relapsed adult inpatients who met DSM-IV criteria for schizophrenia. NNT for a 30% or greater decrease in the Positive and Negative Syndrome Scale total score compared with placebo was consistently lower for the higher dose strengths of 156 and 234 mg, suggesting a therapeutic dose-response. Treatment with paliperidone palmitate at doses between 39 and 156 mg significantly delayed the time to recurrence of symptoms of schizophrenia after 24 weeks of maintained symptom stability. The NNT vs. placebo to avoid a recurrence of symptoms was 5 (95% CI 4-7). Overall, paliperidone palmitate was reasonably well tolerated, with low rates of extrapyramidal symptoms or body weight gain; however, these may be more common at higher doses. Injection site reactions occurred at a rate ranging from 4% to 10%, depending on the dose regimen, compared with 2% for the pooled placebo arms. The acquisition cost of a maintenance dose of paliperidone palmitate calculated on a per day basis is similar to that for risperidone microspheres, but about double the cost for oral paliperidone and approximately 19 times the cost of oral generic risperidone.

CONCLUSIONS

Paliperidone palmitate is efficacious for the acute and maintenance treatment of schizophrenia and is reasonably well tolerated. It offers several advantages over other available second-generation depot antipsychotics: it comes in prefilled syringes in a number of different dosage strengths; it does not require refrigeration; it does not require supplementation with oral antipsychotics; it can be administered once monthly; it can be administered with a very small bore needle; the injection volume is small; the injection site can be either the deltoid or gluteal muscles; it does not require an additional precautionary observation period after the injection. For patients for whom oral risperidone or paliperidone is otherwise effective, paliperidone palmitate offers a guaranteed delivery system that enhances adherence. However, the high acquisition cost of paliperidone palmitate will likely be an important obstacle to its routine use.

Safety and tolerability of deltoid and gluteal injections of paliperidone palmitate in schizophrenia

Paliperidone palmitate is an investigational, injectable atypical antipsychotic. The safety and tolerability of initiating treatment with paliperidone palmitate via deltoid versus gluteal injections given once monthly, and of switching injection sites, in adults with stable schizophrenia were assessed. In this crossover trial, stable outpatients (N=252) were randomly assigned 1:1:1 to 3 dose groups (paliperidone palmitate 50, 75, or 100 mg eq.) and 2 treatment sequences (blinded to dose): deltoid muscle (period 1 [13 weeks]) followed by gluteal muscle (period 2 [12 weeks]) or the reverse. The intent-to-treat analysis set had 249 patients: mean age=43 (SD: 12.8) years; 57% men, 81% white, baseline mean Positive and Negative Syndrome Scale (PANSS) total score=56 (SD: 11.5). A total of 170 (68%) patients completed the study, with a similar proportion completing each treatment sequence. The incidence of systemic treatment-emergent adverse events (TEAEs) was similar between the 2 injection sites across doses during period 1 (deltoid [D]: 61% to 67%; gluteus [G]: 58% to 65%), and during the last 8 weeks of the 2 study periods (DG: 32% to 45% [period 1], 29% to 42% [period 2]; GD: 31% to 40% [period 1], 30% to 41% [period 2]). During the first treatment week, median plasma paliperidone concentrations were higher with treatment initiation in the deltoid muscle compared with the gluteal muscle. At apparent steady state, there was little difference in plasma paliperidone concentrations between the deltoid and gluteus sites for a given dose. Local tolerability was slightly better with gluteal injections. Patient preference for injection sites differed between geographical regions, e.g. patients from the US preferred deltoid to gluteal sites. The most common (>or=5% overall) TEAEs were: (period 1) insomnia, anxiety, headache, and agitation; and (period 2) insomnia, psychotic disorder, weight increased, and tachycardia. Paliperidone palmitate treatment was tolerated, irrespective of injection site, and thus could offer the choice of administration into either the deltoid or gluteal muscle to meet patient and physician preference.

Clinical monitoring and management of the metabolic syndrome in patients receiving atypical antipsychotic medications

Individuals with major mental illness are a high-risk group for cardio-metabolic derangements due to genetic predisposition, developmental and environmental stressors, and lifestyle. This risk is compounded when they receive antipsychotic medications. Guidelines for screening, monitoring, and managing these patients for metabolic problems have been in place for several years. Despite this, recent reports document that this population continues to receive poor care in this regard. In this article, we review the metabolic profile of atypical antipsychotic medications and offer guidelines to reduce the metabolic complications of these agents.

Costs and effects of paliperidone extended release compared with alternative oral antipsychotic agents in patients with schizophrenia in Greece: a cost effectiveness study

BACKGROUND

To compare the costs and effects of paliperidone extended release (ER), a new pharmaceutical treatment for the management of schizophrenia, with the most frequently prescribed oral treatments in Greece (namely risperidone, olanzapine, quetiapine, aripiprazole and ziprasidone) over a 1-year time period.

METHODS

A decision tree was developed and tailored to the specific circumstances of the Greek healthcare system. Therapeutic effectiveness was defined as the annual number of stable days and the clinical data was collected from international clinical trials and published sources. The study population was patients who suffer from schizophrenia with acute exacerbation. During a consensus panel of 10 psychiatrists and 6 health economists, data were collected on the clinical practice and medical resource utilisation. Unit costs were derived from public sources and official reimbursement tariffs. For the comparators official retail prices were used. Since a price had not yet been granted for paliperidone ER at the time of the study, the conservative assumption of including the average of the highest targeted European prices was used, overestimating the price of paliperidone ER in Greece. The study was conducted from the perspective of the National Healthcare System.

RESULTS

The data indicate that paliperidone ER might offer an increased number of stable days (272.5 compared to 272.2 for olanzapine, 265.5 f risperidone, 260.7 for quetiapine, 260.5 for ziprasidone and 258.6 for aripiprazole) with a lower cost compared to the other therapies examined (euro 7,030 compared to euro 7,034 for olanzapine, euro 7,082 for risperidone, euro 8,321 for quetiapine, euro 7,713 for ziprasidone and euro 7,807 for aripiprazole). During the sensitivity analysis, a +/- 10% change in the duration and frequency of relapses and the economic parameters did not lead to significant changes in the results.

CONCLUSION

Treatment with paliperidone ER can lead to lower total cost and higher number of stable days in most of the cases examined.

Paliperidone for schizophrenia

BACKGROUND

Paliperidone, risperidone's active metabolite, is now available in an oral formulation for daily use, and an intramuscular formulation for monthly administration may follow shortly.

OBJECTIVES

To compare effects of oral paliperidone with any other treatment for people with schizophrenia and schizophrenia-like illnesses.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's Register (December 2006), and inspected references of identified studies for further trials. We contacted the manufacturers of paliperidone, the Food and Drug Administration, and authors of relevant trials for additional material.

SELECTION CRITERIA

We included all relevant randomised trials.

DATA COLLECTION AND ANALYSIS

We independently selected and critically appraised studies, extracted data and analysed on an intention-to-treat basis. Where possible and appropriate, we calculated risk ratios (RR) and their 95% confidence intervals (CI) with the number needed to treat (NNT). We calculated Weighted Mean Differences (WMD) for continuous data.

MAIN RESULTS

Five studies compared paliperidone with placebo. Fewer people left the studies early if they were randomized to paliperidone (n=1647, 5 RCTs, RR 0.68 CI 0.61 to 0.76, NNT 7 CI 6 to 9) and those receiving any dose of paliperidone were significantly more likely to have an improvement in global state (n=1420, 4RCTs, RR 0.69 CI 0.63 to 0.75, NNT 5 CI 4 to 6). People randomised to paliperidone were less likely to experience a recurrence of psychosis (n=1638, 5 RCTs, RR 0.45 CI 0.31 to 0.66, NNT 16 CI 13 to 26) than those allocated to placebo. Adverse effect data were not well reported but paliperidone does seem to produce a greater incidence of tachycardia than placebo (n=1638, 5 RCTs, RR1.88 CI 1.28 to 2.76, NNH 21 CI 11 to 90) and a consistent, significant elevation in serum prolactin was found for both men (n=413, 3 RCTs, WMD 27.68 CI 23.66 to 31.69) and women (n=252, 3 RCTs, WMD 87.39 CI 74.27 to 100.51). People receiving paliperidone were more likely to experience extrapyramidal disorders (n=1638, 5 RCTs, RR 2.21 CI 1.26 to 3.88, NNH 28 CI 12 to 129) and weight gain (n=769, 4 RCTs, WMD 1.07 CI 0.65 to 1.49, I-squared 78%) compared with those allocated to placebo. When compared with 10 mg/day olanzapine we found no differences between paliperidone and olanzapine for leaving in the short term (n=1332, 3 RCTs, RR 1.04 CI 0.89 to 1.21; 40% in both groups left by six weeks). Those receiving any dose of paliperidone were no more likely to have a recurrence of psychotic symptoms than those receiving 10 mg/day olanzapine (n=1327, 3 RCTs, RR 0.1.07 CI 0.64 to 1.76). Data from all three studies found paliperidone was less likely to produce a weight change than olanzapine (n=660, 3 RCTs, WMD -0.88 CI -1.38 to -0.37). Results for various movement disorders all favoured olanzapine. There are no clear data relating to social functioning, services use, quality of life, satisfaction and cost.

AUTHORS' CONCLUSIONS

In short-term studies, oral paliperidone is an antipsychotic that is more efficacious than placebo. We found its adverse effects to be similar to those of its parent compound, risperidone, with movement disorders, weight gain, and tachycardia all more common with paliperidone than placebo. In addition, paliperidone is associated with substantial increases in serum prolactin that may be associated with sexual dysfunction, although sexual functioning outcomes were not reported. At doses greater than 3 mg per day, oral paliperidone appears comparable in efficacy to oral olanzapine 10 mg per day. Regarding the critical comparison of oral paliperidone to risperidone, we have no information and are thus unable to determine if paliperidone has any advantages or disadvantages compared to its well-known parent compound.