Risperidone in chronic schizophrenia: a detailed audit, open switch study and two-year follow-up of patients on depot medication

Long-acting injectable versus oral antipsychotics for the maintenance treatment of schizophrenia: a systematic review and comparative meta-analysis of randomised, cohort, and pre-post studies

BACKGROUND

Evidence of comparative benefits of long-acting injectable antipsychotics (LAIs) versus oral antipsychotics for schizophrenia has been inconsistent across study designs. The aim of this study was to evaluate the comparative benefits of LAIs versus oral antipsychotics in three study designs to inform clinical decision making.

METHODS

We did a comprehensive systematic review and meta-analysis comparing LAIs versus oral antipsychotics for schizophrenia covering three study designs: randomised controlled trials (RCTs), cohort studies, and pre-post studies. Our literature search was without language restrictions, in MEDLINE and PubMed, the Cochrane Library, Scopus, and Embase, for studies published from database inception up to a last search on March 13, 2020. We also searched for unpublished studies and ClinicalTrials.gov. We included studies lasting at least 6 months that targeted adults with schizophrenia and related disorders (>80% of participants). Studies on penfluridol (neither an LAI or daily oral antipsychotic), case reports, and case series with fewer than 20 patients were excluded. Two investigators independently extracted study-level data and resolved disagreement by consensus, or via a third investigator. Study authors were contacted to obtain additional information as needed. For our primary outcome we meta-analysed the risk ratio (RR) for hospitalisation or relapse with LAIs versus oral antipsychotics by a random-effects model, with hospitalisation used preferentially over relapse. As secondary analyses, we reversed the preferential order to relapse over hospitalisation, and assessed hospitalisation risk and relapse risk individually. Other secondary outcomes included all meta-analysable data, classed by relevance to effectiveness, efficacy, safety, quality of life, cognitive function, and other outcomes, and analysed by study design. Dichotomous outcomes were expressed as pooled RR and continuous outcomes as standardised mean difference (SMD). The protocol is registered with PROSPERO (CRD42019142094).

FINDINGS

We identified 14 687 records, of which 137 studies (397 319 patients) met the inclusion criteria (32 RCTs [23·4%; 8577 patients], 65 cohort studies [47·4%; 377 447 patients], and 40 pre-post studies [29·2%; 11 295 patients]) and were analysed. The quality of studies in terms of risk of bias varied across study designs and within each study design from low to high. LAIs were associated with a lower risk of hospitalisation or relapse than oral antipsychotics in each of the three study designs (RCTs: 29 studies, 7833 patients, RR 0·88 [95% CI 0·79-0·99], p=0·033; cohort studies: 44 studies, 106 136 patients, RR 0·92 [0·88-0·98], p=0·0044; pre-post studies: 28 studies, 17 876 patients, RR 0·44 [0·39-0·51], p<0·0001). This association was maintained across the study designs when we reversed the preferential order to risk of relapse over hospitalisation, and in individual analysis of hospitalisation risk. The association was maintained only in pre-post studies for relapse risk alone. In all other outcomes related to effectiveness, efficacy, safety, quality of life, cognitive function, and other outcomes, LAIs were more beneficial than oral antipsychotics in 60 (18·3%) of 328 comparisons, not different in 252 (76·8%) comparisons, and less beneficial in 16 (4·9%) comparisons when analysed by study design. Significant heterogeneity was observed across all three study designs. Publication biases were apparent in cohort and pre-post studies, but effect sizes were similar after trim-and-fill analyses.

INTERPRETATION

Although study designs have strengths and weaknesses, including potential low quality of observational studies, we consistently identified significant benefit with LAIs versus oral antipsychotics in preventing hospitalisation or relapse, in settings ranging from restricted research (RCTs) to real-word application (cohort and pre-post studies). Our findings suggest that increased clinical use of LAIs could improve outcomes in schizophrenia.

FUNDING

None.

TRANSLATIONS

For the Chinese, French, German, Italian, Japanese, Portugese and Spanish translations of the abstract see Supplementary Materials section.

Effectiveness of Long-Acting Injectable vs Oral Antipsychotics in Patients With Schizophrenia: A Meta-analysis of Prospective and Retrospective Cohort Studies

Compared with oral antipsychotics (OAPs), long-acting injectable antipsychotics (LAIs) should improve medication adherence and reduce relapses in schizophrenia. However, meta-analyses of randomized trials and mirror-image studies yielded inconsistent results. Nonrandomized cohort studies with parallel comparisons of LAIs and OAPs offer a third design to examine this issue. We meta-analyzed cohort studies with ≥24 weeks duration and hospitalization data. Primary outcome was hospitalization rate, ie, number of hospitalizations per person-year. Secondary outcomes included hospitalization risk, ie, proportion of patients experiencing ≥1 hospitalizations, all-cause discontinuation, and total hospitalization days. Patient severity and/or chronicity at baseline was also meta-analyzed and explored as a potential effect size moderator. Altogether, 42 studies (n = 101 624; follow-up = 18.6 ± 10.0 mo) were meta-analyzed. LAIs were superior to OAPs regarding hospitalization rate (studies = 15, person-years = 68 009, rate ratio = 0.85, 95% CI = 0.78-0.93, P < .001) and all-cause discontinuations (studies = 10, n = 37 293, risk ratio = 0.78, 95% CI = 0.67-0.91, P = .001), but not regarding hospitalization risk (studies = 33, n = 51 733, risk ratio = 0.92, 95% CI = 0.84-1.00, P = .06), and hospitalization days (studies = 11, n = 21 328, Hedges' g = -0.05, 95% CI = -0.16 to 0.06, P = .39). Illness severity/chronicity was significantly greater in patients prescribed LAIs vs OAPs when all available information was pooled together (studies = 23, n = 61 806, Hedges' g = 0.15, 95% CI = 0.03-0.26, P = .01), but not when examined separately. In summary, this meta-analysis of cohort studies, which included patients that are broadly representative of clinical practice, indicates that LAIs are superior to OAPs. The lack of significant superiority of LAIs for hospitalization risk and hospital days needs to be interpreted in the context of naturalistic treatment selection with subsequently greater illness severity/chronicity in LAI-treated patients.

Delivery systems and dosing for antipsychotics

Schizophrenia is a devastating illness, affecting approximately 1-2 % of the world population. Age of onset is generally between 20 and 30 years of age with a chronic, unremitting course for the duration of the patient's life. Although schizophrenia is among the most severe and debilitating illnesses known to medicine, its treatment has remained virtually unchanged for over 50 years. This chapter covers several major concepts in experimental drug development and delivery: (1) the concept of "typical" vs. "atypical" classifications for antipsychotic drugs as it relates to dosing; (2) the development of depot formulations for improved medication adherence; and (3) several promising areas for future therapeutic advances related to the methods and duration of drug administration. These areas include sublingual, injectable, and implantable drug delivery strategies that have the potential to effect rapid and dramatic improvements in schizophrenia outcomes.

Antipsychotic dosing and drug delivery

This chapter addresses the current state of affairs regarding proposed mechanism of action for antipsychotic medications and how this mechanism relates to dosing and delivery strategies. The initial portion describes the history of antipsychotic medication, including key discoveries that contribute to the dopamine hypothesis of schizophrenia and provide evidence that dopamine D2 receptor antagonism remains the most copasetic explanation for both determination of dose and degree of efficacy for current antipsychotic medications. Early observations regarding the unique properties of clozapine and how those observations led to the misconception and misnomer of atypicality are also discussed. Subsequent sections relate the dosing of available medications using chlorpromazine equivalents, with a discussion of non-D2-related mechanisms to antipsychotic effects. The balance of the chapter explores the temporal pattern of receptor occupancy as a key determinant of antipsychotic effectiveness, noting that continuous infusion would present the optimal method of treatment. In addition to the pharmacodynamic benefits of continuous long-term delivery systems, the incidence, causes, and clinical consequences of poor adherence are addressed. These observations are then discussed in the context of clinical studies and meta-analyses, demonstrating superiority of long-term depot preparations over oral administration. However, despite overwhelming evidence in favor of long-term delivery systems, few options are available to provide such ideal medication delivery profiles. Barriers to creating traditional depot preparations for a large number of antipsychotic agents, as well as efforts to address these limitations with polymer-based microspheres are described. The potential extension of current formulations to very long-term delivery implants using biodegradable and nonbiodegradable platforms is then described. Benefits as well as limitations of such systems are discussed with respect to clinical and ethical issues as well as a brief description of potential regulatory and logistic barriers to developing better delivery options. In summary, this chapter describes the basis for relating the dose of all existing antipsychotic medications to dopamine D2 receptor affinity and the potential contribution of continuous occupancy to enhanced efficacy through superior biological effects and improved adherence.

Pharmacokinetics and efficacy of a direct switch from conventional depot to risperidone long-acting injection in Chinese patients with schizophrenic and schizoaffective disorders

AIMS

This 12-week open-label study was designed to investigate the pharmacokinetics and efficacy of a direct switch from a conventional depot to long-acting injectable risperidone in patients with schizophrenia and schizoaffective disorder.

METHODS

Men or women from 18 to 65 years old with a diagnosis of schizophrenia or schizoaffective disorder were eligible for participation if they had been treated with conventional depot for at least 8 weeks before study entry. Intramuscular long-acting risperidone was administered starting from 25 mg, with the dose flexibly adjusted every two weeks for 12 weeks from week 4.

RESULTS

Of the 25 patients enrolled in this study, 21 completed at least one post-baseline assessment and were thus included in the analysis. The mean serum concentration of risperidone plus 9-hydroxyrisperidone was 29.1 ng/mL at the 12th week after switching, with an average injection dose of 31.25 mg long-acting risperidone every two weeks. The levels of active moiety of risperidone seemed to be higher in Chinese patients compared to those in Caucasian patients. Positive and Negative Syndrome Scale total scores (from 67.5 to 56.4; P = 0.002), scores for negative symptoms (P = 0.006) and general symptoms (P = 0.001) were improved significantly 12 weeks after the switch. Mean Extrapyramidal Symptom Rating Scale scores were improved significantly from 20.1 to 5.5 (P < 0.001). Significantly decreased levels of cholesterol and triglyceride were found at the 12th week. The levels of fasting glucose, low-density lipoprotein, high-density lipoprotein and bodyweight remained unchanged.

CONCLUSIONS

These findings suggest that switching from conventional depot to long-acting risperidone is feasible with the advantage of symptom reduction and side-effect profile decrement.

Switching atypical antipsychotics: a review

BACKGROUND

Atypical antipsychotics are increasingly used in the treatment of diverse psychiatric disorders; however, there is little information on the 'why, when, and how' of switching between the different atypical antipsychotics currently available.

OBJECTIVE

To review the data on switching and atypical antipsychotics.

METHODS

A literature search was initially conducted using the key words followed by a search of relevant articles including conference abstracts; relevant pharmaceutical companies were also contacted.

RESULTS

Clinical trial data are limited in terms of parameters measured, and case reports describe specific problems. Few studies are based on real world populations of psychiatric patients over the long-term. Careful patient and drug selections matched to a carefully supervised and appropriate cross titration based upon the pharmacodynamic and pharmacokinetic properties of all of the drugs involved is important to avoid potential complications such as re-emergence or worsening of psychosis and withdrawal, rebound, and emergent phenomena including new or uncovered side-effects. Psychoeducation and involvement of patients and caregivers in the process are also necessary for a successful switch.

CONCLUSION

Despite the prevalence of switching in real world clinical practice, there is a paucity of data to guide clinicians with respect to effective and safe strategies. There are no criteria defining a successful switch. With the increasing range and formulations of atypical antipsychotics available, there is a rationale for their early use to avoid the practical problems associated with switching from conventional antipsychotics as well as the opportunity to maintain patients on an optimal atypical antipsychotic monotherapy.

Switching treatment-resistant patients with schizophrenia or schizoaffective disorder to olanzapine: a one-year open-label study with five-year follow-up

OBJECTIVE

To determine whether patients with treatment-resistant schizophrenia or schizoaffective disorder would respond when switched to olanzapine and whether they could maintain their response on this atypical antipsychotic.

RESEARCH DESIGN AND METHODS

In this single-center, observational, 1-year open-label study, a cohort of patients was switched to olanzapine due to failure on previous treatment. The patients were followed up (retrospectively) for an additional 5 years. Patients had schizophrenia or schizoaffective disorder and all but one were treatment-resistant. The starting dose was 10 mg/day, with dosage adjustments based on physician judgment.

MAIN OUTCOME MEASURES

The CGI-S and CGI-I scales were the primary outcome measures. During the observation period, positive and negative symptoms, hospital readmission rates and duration of hospitalization were measured, and treatment-emergent adverse events recorded.

RESULTS

Mean age of patients (n = 25) was 39.7 years; 19 were male, and all were Caucasian. The mean number of antipsychotics used prior to olanzapine was 4.6 with risperidone (76%) being the most common. The mean duration of olanzapine therapy was 8.6 months. The average number of hospital admissions per patient dropped from 1.32 during the year prior to olanzapine therapy to 0.39 after starting olanzapine. Total number of hospital days was 1042 the year before and 258 the year after olanzapine treatment. The mean CGI-S score improved from markedly ill at baseline to borderline/mildly ill at study end. The mean CGI-I score was rated much improved at study end. Few adverse events occurred during the study. Twelve patients remained on olanzapine monotherapy after 5 years of treatment (mean duration of 62 months).

CONCLUSIONS

Olanzapine may be a treatment option for patients who fail to respond to treatment with other antipsychotics. Importantly, this is one of the first reports showing that patients with schizophrenia can be maintained on atypical antipsychotic monotherapy for at least 5 years.