Intramuscularly injected long-acting testosterone-cholesterol prodrug suspension with three different particle sizes: extended in vitro release and enhanced in vivo safety

The testosterone undecanoate oil solution is the most widely used injection of testosterone for long-acting effects on the market, whereas the formulation carries the potential risk of causing pulmonary vascular embolism, inflammation, and pain at the injection site. Therefore, a sustained-released long-acting injection of testosterone with strong security is urgently exploited. Herein, a poorly water-soluble testosterone-cholesterol prodrug (TST-Chol) was synthesized by esterification. The water solubility of TST-Chol was decreased by 644 folds in comparison to that of testosterone (TST). Moreover, suspensions of TST and TST-Chol were prepared and analyzed in vitro, utilizing three distinct particle sizes: small-sized nanocrystals (SNCs) measuring 300 nm, medium-sized microcrystals (MMCs) measuring 12 μm, and large-sized microcrystals (LMCs) measuring 20 μm. The findings from the in vitro release study indicated that the sustained release of the drug was significantly influenced by the solubility and particle sizes of the suspension. Notably, the suspensions with low water solubility and larger particle sizes exhibited a more desirable sustained-release effect in vitro. Furthermore, the study on pharmacokinetics exhibited that TST-Chol SNCs produced a sustained TST plasma concentration in vivo for up to 40 days and no obvious pathological changes in lung tissue were found. Our study indicated that solubility and particle sizes of suspensions had made a difference in pharmacokinetics and provided a valuable reference for the advancement of long-acting injections.

Association between olanzapine concentration and metabolic dysfunction in drug-naive and chronic patients: similarities and differences

Second-generation antipsychotics are widely used to treat schizophrenia but their use could induce metabolic dysfunction. To balance efficacy and side effects, various guidelines recommend the use of therapeutic drug monitoring. Given the controversial relationship between olanzapine serum concentration and metabolic dysfunction, its use in clinical practice is still debated. To address this issue, we conducted a prospective cohort study to explore the associations in patients with schizophrenia. Specifically, first-episode drug-naive patients and patients with chronic schizophrenia were recruited. All participants received olanzapine monotherapy for 8 weeks. Anthropometric parameters and metabolic indices were tested at baseline and at week 8, and olanzapine serum concentration was tested at week 4. After 8 weeks of observation, body weight and BMI increased significantly in drug-naive patients. Moreover, triglycerides and LDL increased significantly in both drug-naive and chronic patients. Among chronic patients, those who have never used olanzapine/clozapine before had a significantly higher increase in weight and BMI than those who have previously used olanzapine/clozapine. Furthermore, olanzapine concentration was associated with changes in weight, BMI, and LDL levels in the drug-naive group and glucose, triglyceride and LDL levels in chronic patients who have not used olanzapine/clozapine previously. In conclusion, the metabolic dysfunction induced by olanzapine is more severe and dose-dependent in drug-naive patients but independent in patients with chronic schizophrenia. Future studies with a longer period of observation and a larger sample are warranted.

An ion-paired moxifloxacin nanosuspension eye drop provides improved prevention and treatment of ocular infection

There are numerous barriers to achieving effective intraocular drug administration, including the mucus layer protecting the ocular surface. For this reason, antibiotic eye drops must be used multiple times per day to prevent and treat ocular infections. Frequent eye drop use is inconvenient for patients, and lack of adherence to prescribed dosing regimens limits treatment efficacy and contributes to antibiotic resistance. Here, we describe an ion-pairing approach used to create an insoluble moxifloxacin-pamoate (MOX-PAM) complex for formulation into mucus-penetrating nanosuspension eye drops (MOX-PAM NS). The MOX-PAM NS provided a significant increase in ocular drug absorption, as measured by the area under the curve in cornea tissue and aqueous humor, compared to Vigamox in healthy rats. Prophylactic and treatment efficacy were evaluated in a rat model of ocular Staphylococcus aureus infection. A single drop of MOX-PAM NS was more effective than Vigamox, and completely prevented infection. Once a day dosing with MOX-PAM NS was similar, if not more effective, than three times a day dosing with Vigamox for treating S. aureus infection. The MOX-PAM NS provided increased intraocular antibiotic absorption and improved prevention and treatment of ocular keratitis, and the formulation approach is highly translational and clinically relevant.

Evaluating parameters affecting drug fate at the intramuscular injection site

Intramuscular (IM) injections are a well-established method of delivering a variety of therapeutics formulated for parenteral administration. While the wide range of commercial IM pharmaceuticals provide a wealth of pharmacokinetic (PK) information following injection, there remains an inadequate understanding of drug fate at the IM injection site that could dictate these PK outcomes. An improved understanding of injection site events could improve approaches taken by formulation scientists to identify therapeutically effective and consistent drug PK outcomes. Interplay between the typically non-physiological aspects of drug formulations and the homeostatic IM environment may provide insights into the fate of drugs at the IM injection site, leading to predictions of how a drug will behave post-injection in vivo. Immune responses occur by design after e.g. vaccine administration, however immune responses post-injection are not in the scope of this article. Taking cues from existing in vitro modelling technologies, the purpose of this article is to propose "critical parameters" of the IM environment that could be examined in hypothesis-driven studies. Outcomes of such studies might ultimately be useful in predicting and improving in vivo PK performance of IM injected drugs.

Converting oral to long-acting injectable antipsychotics: a guide for the perplexed

There has been increasing recognition that antipsychotic nonadherence is common across all stages of schizophrenia, starting from the first episode. Moreover, numerous meta-analyses of the existing literature indicate superiority of long-acting injectable (LAI) over oral antipsychotics when one adjusts for the greater illness severity and duration among patients in LAI antipsychotic trials. The increasing availability of LAI antipsychotic options has raised interest in converting patients from oral medication; however, the successful transition from oral to the comparable LAI antipsychotic requires an understanding of the current extent of antipsychotic exposure, the kinetics of the LAI preparation, and the expected plasma levels achieved by the LAI formulation. The purpose of this article is to provide, in a concise format, the essential information for converting patients to the LAI forms of haloperidol, fluphenazine, risperidone, paliperidone, olanzapine, and aripiprazole from the comparable oral medication, and how the use of plasma antipsychotic levels can be invaluable for this process.

Olanzapine pamoate for the treatment of schizophrenia--a safety evaluation

INTRODUCTION

Non-adherence to long-term treatment is a major issue for patients with schizophrenia and is associated with an increased risk of relapse. Long-acting injectable (LAI) antipsychotics can offer a useful option to improve adherence. Due to the type of sustained-release mechanism, olanzapine pamoate (OLAI) can differ in safety as compared with oral olanzapine. Recent safety data concerning olanzapine pamoate required an update of previous systematic reviews.

AREAS COVERED

Safety data were found in US and EU clinical trial registries, and a literature search was undertaken using the databases PubMed and EMBASE to find all relevant published studies. Where appropriate, the number needed to harm and 95% confidence interval for categorical safety outcomes were calculated.

EXPERT OPINION

The safety profile of OLAI was similar to the well-known safety profile of oral olanzapine, except for the risk of occurrence of post-injection delirium/sedation syndrome (PDSS). Olanzapine pamoate can be a choice for schizophrenic patients with a history of response to and acceptable tolerance of oral olanzapine, who have easy access to mental healthcare settings with emergency services for the treatment of PDSS. Long-term, prospective studies assessing the efficacy and safety of OLAI and head-to-head comparisons with other LAI and oral antipsychotics are needed.

Clinical outcomes with olanzapine long-acting injection: impact of the 3-hour observation period on patient satisfaction and well-being

BACKGROUND

The objective of the present analysis is to determine the impact of the 3-hour observation period for olanzapine long-acting injection (LAI) on patient satisfaction and well-being by comparing data collected before and after its implementation.

METHODS

This is a post hoc analysis of patients treated with olanzapine LAI in 1) a 6-month fixed-dose randomized controlled trial and/or 2) a 6-year open-label safety study. This analysis was limited to patients with schizophrenia who were treated with olanzapine LAI consistent with the approved indication and dosing recommendations of the European Union Summary of Product Characteristics (N=966). Of the 966 patients, the analysis further focused only on those patients who received both 1) at least one injection before the implementation of the 3-hour observation period and 2) at least one injection after implementation of the 3-hour observation period (N=487). Patient satisfaction was assessed with the three-item Patient Satisfaction with Medication Questionnaire-Modified. Responses were averaged across all postbaseline visits occurring before (ie, without) the implementation of the 3-hour observation period and across all postbaseline visits occurring after (ie, with) the implementation of the 3-hour observation period. In addition, the rate of postinjection delirium/sedation syndrome events was calculated.

RESULTS

There was no meaningful change after implementation of the 3-hour observation period in satisfaction (before: mean [SD] =4.0 [1.02] and after: mean [SD] =4.1 [0.82]), preference for olanzapine LAI over oral medication (before: mean [SD] =4.0 [0.90] and after: mean [SD] =4.1 [0.77]), or ratings of satisfaction regarding side effects (before: mean [SD] =1.9 [0.79] and after: mean [SD] =1.8 [0.60]). For the total population (N=966), postinjection delirium/sedation syndrome occurred in 26 (0.07%) of 38,010 injections.

CONCLUSION

For patients with schizophrenia receiving treatment with olanzapine LAI, the 3-hour observation period had no impact on their satisfaction with the medication or on their subjective well-being.

A 6-year open-label study of the efficacy and safety of olanzapine long-acting injection in patients with schizophrenia: a post hoc analysis based on the European label recommendation

PURPOSE

To assess the long-term efficacy and safety of olanzapine long-acting injection (LAI) in the treatment of schizophrenia, focusing on clinical trial data consistent with the approved indication and dosing recommendations in the European label and which forms the basis for treatment decisions made by clinicians in daily clinical practice.

PATIENTS AND METHODS

This was a post hoc analysis of a 6-year open-label study of olanzapine LAI in patients (male or female, 18-75 years old) with schizophrenia entering this study following feeder studies of olanzapine LAI. Patients were flexibly dosed (45-405 mg, 2- to 4-week intervals), but those receiving oral olanzapine supplementation whose total olanzapine dose was >20 mg/day equivalent were excluded from this post hoc analysis.

RESULTS

Data from 669 patients were analyzed (44.5% completed). Positive and Negative Syndrome Scale total scores did not change significantly from baseline to endpoint; Clinical Global Impression-Severity scores improved significantly. Mean weight change was +2.19 kg (P<0.001), with 40.8% of patients experiencing ≥7% weight gain. There were 24 occurrences of post-injection delirium/sedation syndrome (PDSS).

CONCLUSION

Olanzapine LAI appeared to be effective in the long-term maintenance of schizophrenia, and the safety profile was consistent with that of oral olanzapine, except for injection-related events and PDSS events.

Post-injection delirium/sedation syndrome in patients treated with olanzapine pamoate: mechanism, incidence, and management

Second-generation antipsychotics (SGAs) are a mainstay in the treatment of patients with schizophrenia. However, continuity in intake of the prescribed medication has been one of the greatest challenges in these patients. One option to improve medication adherence is to prescribe depot or long-acting injectable formulations (LAIs) of antipsychotics. Following risperidone, several other SGAs have been introduced as LAIs. Olanzapine pamoate, paliperidone palmitate, and aripiprazole are the new-generation LAIs, which are available for 2- to 4-week intervals of application in many countries. The literature shows a clear advantage of these drugs over placebo regarding symptom reduction and relapse prevention. LAIs show a similar safety profile to oral formulations of the relevant drug, with the exception of olanzapine pamoate, which can lead to rare cases of post-injection delirium/sedation syndrome (PDSS). PDSS is characterized by heavy sedation (possibly including coma) and/or delirium after injection. During PDSS events, patients show higher plasma concentrations of olanzapine, leading to the assumption that unintended partial intravascular injection or blood vessel injury during the injection is causative of PDSS. Therefore, a risk-management plan proposing an observation period of 3 h was introduced. In August 2013, a new proposal by the European Medicines Agency terminated the requirement to accompany these patients to their next destination, although this requirement remains in place according to US FDA recommendations.

Long-acting olanzapine versus long-acting risperidone for schizophrenia in Spain - a cost-effectiveness comparison

BACKGROUND

In schizophrenia, medication adherence is critical to achieve better patient outcomes and to avoid relapses, which are responsible for a significant proportion of total healthcare costs for this chronic illness. The aim of this study was to assess the cost-effectiveness of olanzapine long-acting injection (OLAI) compared with risperidone long-acting injection (RLAI) in patients with schizophrenia in Spain.

METHODS

A discrete event simulation (DES) model was developed from a Spanish healthcare system perspective to estimate clinical and economic outcomes for patients with schizophrenia over a five-year period. Patients who had earlier responded to oral medication and have a history of relapse due to adherence problems were considered. Identical model populations were treated with either OLAI or RLAI. In the absence of a head-to-head clinical trial, discontinuation and relapse rates were obtained from open-label studies. The model accounted for age, gender, risks of relapse and discontinuation, relapse management, hospitalization, treatment switching and adverse events. Direct medical costs for the year 2011 and outcomes including relapse avoided, life years (LYs), and quality-adjusted life years (QALYs) were discounted at a rate of 3%.

RESULTS

When comparing RLAI and OLAI, the model predicts that OLAI would decrease 5-year costs by €2,940 (Standard Deviation between replications 300.83), and result in a QALY and LY gains of 0.07 (SD 0.019) and 0.04 (SD 0.025), respectively. Patients on OLAI had fewer relapses compared to RLAI (1.392 [SD 0.035] vs. 1.815 [SD 0.035]) and fewer discontinuations (1.222 [SD 0.031] vs. 1.710 [SD 0.039]). Sensitivity analysis indicated that the study was robust and conclusions were largely unaffected by changes in a wide range of parameters.

CONCLUSIONS

The present evaluation results in OLAI being dominant over RLAI, meaning that OLAI represents a more effective and less costly alternative compared to RLAI in the treatment of patients with schizophrenia in the Spanish setting.

Pharmacokinetics of olanzapine long-acting injection: the clinical perspective

Olanzapine long-acting injection (OLAI) is a sustained-release depot antipsychotic for the treatment of schizophrenia in adults. Our objective was to explain the pharmacokinetics of OLAI to provide clinical insight. Simulation models and data from clinical trials are presented. Olanzapine concentrations were observed immediately upon injection. Half-life was ∼30 days, controlled by the slow rate of intramuscular absorption rather than the 30-h elimination rate-based half-life of oral olanzapine. As each injection builds on the drug still being released from previous injections, concentrations increase gradually until a steady state is reached after ∼3 months. Concentrations were similar to oral olanzapine and proportional to the dose; the average steady-state concentrations (10th-90th percentile) for the 150, 210, and 300 mg/2-week doses were 16-32, 15-55, and 20-67 ng/ml, respectively, and those for the 300 and 405 mg/4-week doses were 19-48 and 19-62 ng/ml, respectively. Peak concentrations most often occurred at 2-4 days after injection. Peak-to-trough fluctuation was greater for the 4-week dosing interval than the 2-week one, with no apparent clinical ramifications for these differences. Trough concentrations were above the lower end of the therapeutic range, even at the first injection. Long-term use up to 6 years indicated no additional accumulation. The impact of smoking and sex was similar, but less pronounced than for oral olanzapine.

Long-acting atypical antipsychotics: characterization of the local tissue response

Purpose

Long-acting injectables (LAIs) are increasingly recognized as an effective therapeutic approach for treating chronic conditions. Many LAIs are formulated to create a poorly soluble depot from which the active agent is delivered over time. This long residing depot can cause localized chronic-active inflammation in the tissue, which has not been well defined in the literature. The purpose of this work is to establish an experimental baseline for describing these responses.

Methods

Non-human primates and rodents were used to examine the response to LAI formulations of two clinically relevant atypical antipsychotics, aripiprazole monohydrate and olanzapine pamoate monohydrate.

Results

A foreign body response develops with elevations of key cytokines such as IL-1α, IL-1β, TNFα, and IL6 at the site of injection. However, the tissue response for the two atypical antipsychotics compounds diverge as evidenced by quantitative differences observed in cytokine levels at various time points after dosing.

Conclusions

Our studies show that, while the drugs are in the same therapeutic class, the response to each of these compounds can be distinguished qualitatively and quantitatively, supporting the idea that the injection site reaction involves a multiplicity of factors including the properties of the compound and cellular dynamics at the site of injection.

Schizophrenia relapse and the clinical usefulness of once-monthly aripiprazole depot injection

Improving medication adherence is critical to improving outcomes in patients with schizophrenia. A long-acting injectable (depot) antipsychotic is one of the most effective methods for improving treatment adherence and decreasing rehospitalization rates in patients with schizophrenia. Until recently, only three second-generation antipsychotics were available in a long-acting injectable formulation (risperidone, paliperidone, and olanzapine). In this respect, the emergence of long-acting aripiprazole injection (ALAI), approved by the US Food and Drug Administration for the treatment of schizophrenia in 2013, is timely. ALAI is a lyophilized powder of aripiprazole, and the aripiprazole molecule is unmodified. The initial and target dosage of ALAI is 400 mg once monthly, but it could be reduced to 300 mg if adverse reactions occur with 400 mg. When first administering ALAI, it is recommended to continue treatment with oral aripiprazole (10-20 mg/day) or another oral antipsychotic for 2 weeks in order to maintain therapeutic antipsychotic concentrations. The primary clearance route for ALAI is hepatic, ie, cytochrome P450 (CYP)2D6 and CYP3A4, so dose adjustment is required in poor CYP2D6 metabolizers. The efficacy of ALAI was demonstrated in three studies. A randomized controlled trial that formed the basis for approval of ALAI in the treatment of schizophrenia showed that ALAI significantly delayed time to impending relapse when compared with placebo (P<0.0001, log-rank test). An open-label, mirror study demonstrated that total psychiatric hospitalization rates were significantly lower after switching from oral antipsychotics to ALAI. Another randomized controlled trial presented in poster form suggested that ALAI 400 mg was comparable with oral aripiprazole 10-30 mg in preventing relapse. ALAI was generally well tolerated during both short-term and long-term studies. Its tolerability profile, including extrapyramidal symptoms and clinically relevant metabolic parameters, was similar to placebo. However, insomnia, headache, anxiety, akathisia, weight gain, injection site pain, and tremor need clinical attention. These studies suggest that ALAI is a viable treatment option for patients with schizophrenia, but direct head-to-head comparisons between ALAI and other long-acting injectable antipsychotics are needed to elucidate its risk-benefit profile.

Understanding depot antipsychotics: an illustrated guide to kinetics

Long-acting injectable (LAI) antipsychotics can have considerable advantages over oral medications for the management of patients with schizophrenia. Despite the high prevalence of treatment nonadherence with oral pharmacotherapy, LAI antipsychotics are significantly underutilized in this patient population. The availability of newer LAI antipsychotic preparations combined with a resurgent interest in the use of typical antipsychotics has rekindled awareness of the value of LAI medications. This article is intended to provide a visual understanding of the various kinetic profiles of LAI antipsychotics to facilitate initiation and greater use of these agents.

Drug safety evaluation of olanzapine pamoate

INTRODUCTION

Olanzapine pamoate is one of three second-generation antipsychotics available as depot medication. While non-adherence is a major problem in the treatment of schizophrenia, olanzapine pamoate can improve adherence, though its use is limited by its safety profile.

AREAS COVERED

The review covers data on efficacy with a focus on tolerability and safety of olanzapine pamoate using the known databases including PubMed, Psychinfo and Embase using keywords. Relevant websites were also reviewed.

EXPERT OPINION

Olanzapine is an efficacious antipsychotic that can be used in its oral and depot formula (olanzapine pamoate) for the treatment of patients with schizophrenia. It has demonstrated superiority over conventional and some other atypical antipsychotics, with both formulas having comparable low rates of motor side effects. The side effects on body weight and glucose homeostasis are also similar in both formulas and limit its use. The only clear difference regarding side effects is 'the risk that 0.07% of injections in preclinical trials have led to a post-injection delirium/sedation syndrome event which requires a risk management plan'. Especially in outpatients this could cause inconveniences that should be overcome by offering, for example, psychological therapies or psychoeducation to effectively use the time when patients have to remain in the healthcare facilities.

Preparation, Characterization, and In Vivo Evaluation of Olanzapine Poly(D,L-lactide-co-glycolide) Microspheres

The aim of this study was to prepare injectable depot formulations of Olanzapine using four poly(D,L-lactide-co-glycolide) (PLGA) polymers of varying molecular weight and copolymer composition, and evaluate in vivo performance in rats. In vivo release profiles from the formulations were governed chiefly by polymer molecular weight and to a lesser extent, copolymer composition. Formulations A and B, manufactured using low molecular weight PLGA and administered at 10 mg/kg dose, released drug within 15 days. Formulation C, prepared from intermediate molecular weight PLGA and administered at 20 mg/kg dose, released drug in 30 days, while Formulation D, manufactured using a high molecular weight polymer and administered at 20 mg/kg dose, released drug in 45 days. A simulation of multiple dosing at 7- and 10-day intervals for Formulations A and B revealed that steady state was achieved within 7-21 days and 10-30 days, respectively. Similarly, simulations at 15-day intervals for Formulations C and D indicated that steady state levels were reached during days 15-45. Overall, steady state levels for 7-, 10-, or 15-day dosing ranged between 45 and 65 ng/mL for all the formulations, implying that Olanzapine PLGA microspheres can be tailored to treat patients with varying clinical needs.

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.

Comparing tolerability of olanzapine in schizophrenia and affective disorders: a meta-analysis

BACKGROUND

Olanzapine is prescribed for a number of psychiatric disorders, including schizophrenia, bipolar mania, and unipolar and bipolar depression. Olanzapine treatment is associated with tolerability issues such as metabolic adverse effects (e.g. weight gain, increase in blood glucose, triglycerides and total cholesterol levels), extrapyramidal symptoms [EPS] (e.g. parkinsonism, akathisia, tardive dyskinesia) and sedative adverse effects. Metabolic issues lead to some long-term consequences, which include cardiovascular diseases (CVD) and type 2 diabetes mellitus, and these complications cause high rates of mortality and morbidity among patients with severe mental illnesses. The expanded indications of olanzapine in psychiatry suggest a need to investigate whether there is a difference in the incidence and severity of adverse effects related to category diagnosis. Are the adverse effects expressed differently according to phenotype? Unfortunately, there are no reported studies that investigated these differences in adverse effects associated with olanzapine treatment in psychiatric patients with different phenotypes.

OBJECTIVE

The aim of the present meta-analysis is to separately examine olanzapine-induced cardiometabolic adverse effects and EPS in patients with schizophrenia and affective disorders.

DATA SOURCES

A search of computerized literature databases PsycINFO (1967-2010), PubMed (MEDLINE), EMBASE (1980-2010) and the clinicaltrials.gov website for randomized clinical trials was conducted. A manual search of reference lists of published review articles was carried out to gather further data.

STUDY SELECTION

Randomized controlled trials were included in our study if (i) they assessed olanzapine adverse effects (metabolic or extrapyramidal) in adult patients with schizophrenia or affective disorders; and (ii) they administered oral olanzapine as monotherapy during study.

DATA EXTRACTION

Two reviewers independently screened abstracts for choosing articles and one reviewer extracted relevant data on the basis of predetermined exclusion and inclusion criteria. It should be mentioned that for the affective disorders group we could only find articles related to bipolar disorder.

DATA SYNTHESIS

Thirty-three studies (4831 patients) that address olanzapine monotherapy treatment of adults with schizophrenia or bipolar disorder were included in the analysis. The primary outcomes were metabolic adverse effects (changes in weight, blood glucose, low-density lipoprotein, total cholesterol and triglyceride levels). The secondary outcomes of our study were assessing the incidence of some EPS (parkinsonism, akathisia and use of antiparkinson medication). The tolerability outcomes were calculated separately for the schizophrenia and bipolar disorder groups and were combined in a meta-analysis. Tolerability outcomes show that olanzapine contributes to weight gain and elevates blood triglycerides, glucose and total cholesterol levels in both schizophrenia and bipolar disorder patients. However, olanzapine treatment produced significantly more weight gain in schizophrenia patients than in bipolar disorder patients. In addition, increases in blood glucose, total cholesterol and triglyceride levels were higher in the schizophrenia group compared with the bipolar disorder group, even though these differences were not statistically significant. Based on our results, the incidence of parkinsonism was significantly higher in the schizophrenia group than in the bipolar disorder group. Subgroup analysis and logistic regression were used to assess the influence of treatment duration, dose, industry sponsorship, age and sex ratio on tolerability outcome.

CONCLUSIONS

Our results suggest that schizophrenia patients may be more vulnerable to olanzapine-induced weight gain. The findings may be explained by considering the fact that in addition to genetic disposition for metabolic syndrome in schizophrenia patients, they have an especially high incidence of lifestyle risk factors for CVD, such as poor diet, lack of exercise, stress and smoking. It might be that an antipsychotic induces severity of adverse effect according to the phenotype.

Efficacy of olanzapine long-acting injection in patients with acutely exacerbated schizophrenia: an insight from effect size comparison with historical oral data

BACKGROUND

To treat acute schizophrenia, a long-acting injectable antipsychotic needs a rapid onset of action and therapeutic profile similar to that of oral agents. The present post-hoc analyses compared results from a randomized, double-blind, placebo-controlled trial of olanzapine long-acting injection (LAI) for acute schizophrenia with those observed in similarly designed trials of oral olanzapine.

METHODS

Six-week results from the olanzapine LAI study (N = 404) were compared with those of 3 oral studies (study 1: olanzapine vs. haloperidol vs. placebo [N = 335]; study 2: olanzapine vs. haloperidol vs. low-dose olanzapine [N = 431]; study 3: olanzapine vs. placebo vs. low-dose olanzapine [N = 152]). All patients had baseline Brief Psychiatric Rating Scale (BPRS) scores ≥24 (0-6 scale). Six-week effect sizes were calculated. Efficacy onset, pharmacokinetics, discontinuations, weight gain, and extrapyramidal symptoms were also assessed.

RESULTS

At 6 weeks, mean BPRS scores decreased by 14 to 15 points for olanzapine LAI (405 mg/4 weeks, 210 or 300 mg/2 weeks), by 8 to 16 for oral olanzapine (10 ± 2.5 or 15 ± 2.5 mg/day), and by 12 to 13 for haloperidol (15 ± 5 mg/day). For those same dose groups, effect sizes vs. placebo for the BPRS were 0.7 to 0.8 for olanzapine LAI, 0.5 to 0.7 for oral olanzapine, and 0.6 for haloperidol. The first statistically significant separation from placebo on the BPRS occurred at 3 days for the olanzapine LAI groups and at 1 week for oral olanzapine and haloperidol (15 ± 5 mg/day) in oral study 1 although as late as week 6 for the 10-mg/day olanzapine dose in oral study 3. Olanzapine concentrations were similar across studies. Weight gain ≥7% of baseline occurred in up to 35% of olanzapine LAI and oral patients versus up to 12% of haloperidol and placebo patients. Extrapyramidal symptoms were lowest in the olanzapine LAI groups and significantly greater in the haloperidol groups. No post-injection delirium/sedation syndrome events occurred in the olanzapine LAI study.

CONCLUSIONS

Patients treated acutely with olanzapine LAI showed a similar pattern of improvement to that seen historically with oral olanzapine. With the exception of injection-related adverse events, the efficacy and tolerability profile of olanzapine LAI is similar to oral olanzapine.

TRIAL REGISTRATION

ClinicalTrials.gov ID; URL: http://http//www.clinicaltrials.gov/: NCT00088478; ClinicalStudyResults.org ID; URL: http://www.clinicalstudyresults.org/: 917, 978, 982, and 5984.

Modeling chronic olanzapine exposure using osmotic minipumps: pharmacological limitations

Animal models can face unique challenges in mirroring what occurs in humans. This is the case for antipsychotics in rodents, where these drugs are metabolized much more rapidly. One strategy to address this issue has been the use of osmotic minipumps to ensure continuous antipsychotic exposure over prolonged intervals, which is routinely the case when these same drugs are administered to humans. More recently, it has been identified that with olanzapine this approach may be compromised by oxidative degradation, a process that can be observed within days. Further, in vivo evidence has reported progressive decreases in plasma levels over a 1-month interval. To address this issue in vitro, osmotic minipumps (n=4), with olanzapine at a concentration resulting in a dose of 7.5mg/kg/day in vivo, were placed in saline-filled Falcon tubes and immersed in a water bath. Olanzapine concentrations were assessed in the minipumps as well as the surrounding water bath at baseline, 1h, and days 1, 7, 14, 21, and 28. Minipump results indicated a monophasic exponential decay and a half-life of 14.8 days (95% CI=13.1-17.1 days). Results from the water bath demonstrated a linear increase in olanzapine up to and including day 21, followed thereafter by a decrease to day 28. It is concluded that administration of olanzapine via osmotic minipump is viable in animal models to mirror what occurs in humans, although the interval should be confined to 2 weeks. As well, strategies in dissolving olanzapine to diminish oxidation are discussed.