Comparative effectiveness of fluphenazine decanoate injections every 2 weeks versus every 6 weeks

Time-dependent effect of antipsychotic discontinuation and dose reduction on social functioning and subjective quality of life-a multilevel meta-analysis

Background

Meta-analyses indicate superiority of antipsychotic maintenance treatment over discontinuation within up to 24 months after treatment initiation for patients with schizophrenia-spectrum disorders. In terms of functional recovery, long-term trials show improved functioning after discontinuation, suggesting a time-dependent effect of antipsychotic maintenance. However, these trials were not included in previous meta-analyses. We therefore investigated whether the effect of antipsychotic maintenance treatment vs. discontinuation on social functioning and quality of life varies by trial length.

Methods

The study was preregistered with PROSPERO (CRD42021248933). PubMed, PsycINFO, Web of Science, Embase and trial registers were systematically searched on 8th November 2021 and updated on 25th June, 2023 and 10th August, 2023 for studies that compared antipsychotic maintenance to discontinuation and reported data on social functioning or subjective quality of life in patients with schizophrenia-spectrum disorders. Risk of bias was assessed with the RoB 2, the ROBINS-I and the RoB-ME tools. Quality of evidence was rated using the Grading of Recommendations Assessment, Development, and Evaluation approach.

Findings

We included k = 35 studies (N = 5924) with follow-ups between one month and 15 years. Overall, maintenance and discontinuation did not differ on social functioning (k = 32; n = 5330; SMD = 0.204; p = 0.65; 95% CI [-0.69, 1.10]) or quality of life (k = 10; n = 943; SMD = -0.004; p = 0.97; 95% CI [-0.22, 0.21]), whilst subgroup analyses of middle- (2-5 years; k = 7; n = 1032; SMD = 0.68; 95% CI [0.06, 1.28]) and long-term follow-ups (>5 years; k = 2; n = 356; SMD = 1.04; 95% CI [0.82, 1.27]) significantly favoured discontinuation. However, the quality of evidence was rated as very low.

Interpretation

Although our findings suggest a time-dependent decrease in the effect of maintenance treatment on social functioning, interpretation of these findings is limited by the serious risk of bias in middle- and long-term trials. Therefore, any conclusions regarding the long-term benefits of antipsychotic treatment or discontinuation for functional recovery are premature and more high-quality trials tailored to comparing state of the art maintenance treatment vs. discontinuation are needed.

Funding

None.

Risk Factors for Psychotic Relapse After Dose Reduction or Discontinuation of Antipsychotics in Patients With Chronic Schizophrenia. A Meta-Analysis of Randomized Controlled Trials

BACKGROUND AND HYPOTHESIS

Although maintenance treatment with antipsychotics protects against psychotic relapse, high doses may hamper recovery. Therefore, dose reduction or discontinuation may be considered in patients with chronic schizophrenia. Here, we identified risk factors for psychotic relapse when doses are reduced.

STUDY DESIGN

We systematically searched MEDLINE, EMBASE, and PsycINFO from January 1950 through January 2021 and reviewed randomized controlled trials (RCTs) that reported relapse rates after antipsychotic dose reduction or discontinuation in patients with chronic schizophrenia. We calculated relative risks (RRs) with 95% confidence intervals (CIs) per person-year and sought to identify potential risk factors for relapse. The study is registered with PROSPERO (CRD42017058296).

STUDY RESULTS

Forty-seven RCTs (54 patient cohorts, 1746 person-years) were included. The RR for psychotic relapse with dose reduction/discontinuation versus maintenance treatment was 2.3 per person-year (95% CI: 1.9 to 2.8). The RR was higher with antipsychotic discontinuation, dose reduction to less than 3-5 mg haloperidol equivalent (HE), or relatively rapid dose reduction (<10 weeks). The RR was lower with long-acting injectable agents versus oral antipsychotic dose reduction. Other factors that increased the risk of psychotic relapse were younger age and short follow-up time.

CONCLUSIONS

Clinicians should take several risk factors for psychotic relapse into account when considering dose reduction in patients with chronic schizophrenia. Studies of a relatively fast reduction in antipsychotic dose support a minimum dose of 3-5 mg HE. However, if the dose is tapered more gradually, relapses related to medication withdrawal might be avoided, possibly enabling lower-end doses to be achieved.

Antipsychotic dose reduction compared to dose continuation for people with schizophrenia

BACKGROUND

Antipsychotic drugs are the mainstay treatment for schizophrenia, yet they are associated with diverse and potentially dose-related side effects which can reduce quality of life. For this reason, the lowest possible doses of antipsychotics are generally recommended, but higher doses are often used in clinical practice. It is still unclear if and how antipsychotic doses could be reduced safely in order to minimise the adverse-effect burden without increasing the risk of relapse.

OBJECTIVES

To assess the efficacy and safety of reducing antipsychotic dose compared to continuing the current dose for people with schizophrenia.

SEARCH METHODS

We conducted a systematic search on 10 February 2021 at the Cochrane Schizophrenia Group's Study-Based Register of Trials, which is based on CENTRAL, MEDLINE, Embase, CINAHL, PsycINFO, PubMed, ClinicalTrials.gov, ISRCTN, and WHO ICTRP. We also inspected the reference lists of included studies and previous reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing any dose reduction against continuation in people with schizophrenia or related disorders who were stabilised on their current antipsychotic treatment.  DATA COLLECTION AND ANALYSIS: At least two review authors independently screened relevant records for inclusion, extracted data from eligible studies, and assessed the risk of bias using RoB 2. We contacted study authors for missing data and additional information. Our primary outcomes were clinically important change in quality of life,  rehospitalisations and dropouts due to adverse effects; key secondary outcomes were clinically important change in functioning, relapse, dropouts for any reason, and at least one adverse effect. We also examined scales measuring symptoms, quality of life, and functioning as well as a comprehensive list of specific adverse effects. We pooled outcomes at the endpoint preferably closest to one year. We evaluated the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 25 RCTs, of which 22 studies provided data with 2635 participants (average age 38.4 years old). The median study sample size was 60 participants (ranging from 18 to 466 participants) and length was 37 weeks (ranging from 12 weeks to 2 years). There were variations in the dose reduction strategies in terms of speed of reduction (i.e. gradual in about half of the studies (within 2 to 16 weeks) and abrupt in the other half), and in terms of degree of reduction (i.e. median planned reduction of 66% of the dose up to complete withdrawal in three studies). We assessed risk of bias across outcomes predominantly as some concerns or high risk.  No study reported data on the number of participants with a clinically important change in quality of life or functioning, and only eight studies reported continuous data on scales measuring quality of life or functioning. There was no difference between dose reduction and continuation on scales measuring quality of life (standardised mean difference (SMD) -0.01, 95% confidence interval (CI) -0.17 to 0.15, 6 RCTs, n = 719, I2 = 0%, moderate certainty evidence) and scales measuring functioning (SMD 0.03, 95% CI -0.10 to 0.17, 6 RCTs, n = 966, I2 = 0%, high certainty evidence). Dose reduction in comparison to continuation may increase the risk of rehospitalisation based on data from eight studies with estimable effect sizes; however, the 95% CI does not exclude the possibility of no difference (risk ratio (RR) 1.53, 95% CI 0.84 to 2.81, 8 RCTs, n = 1413, I2 = 59% (moderate heterogeneity), very low certainty evidence). Similarly, dose reduction increased the risk of relapse based on data from 20 studies (RR 2.16, 95% CI 1.52 to 3.06, 20 RCTs, n = 2481, I2 = 70% (substantial heterogeneity), low certainty evidence).   More participants in the dose reduction group in comparison to the continuation group left the study early due to adverse effects (RR 2.20, 95% CI 1.39 to 3.49, 6 RCTs with estimable effect sizes, n = 1079, I2 = 0%, moderate certainty evidence) and for any reason (RR 1.38, 95% CI 1.05 to 1.81, 12 RCTs, n = 1551, I2 = 48% (moderate heterogeneity), moderate certainty evidence). Lastly, there was no difference between the dose reduction and continuation groups in the number of participants with at least one adverse effect based on data from four studies with estimable effect sizes (RR 1.03, 95% CI 0.94 to 1.12, 5 RCTs, n = 998 (4 RCTs, n = 980 with estimable effect sizes), I2 = 0%, moderate certainty evidence).  AUTHORS' CONCLUSIONS: This review synthesised the latest evidence on the reduction of antipsychotic doses for stable individuals with schizophrenia. There was no difference between dose reduction and continuation groups in quality of life, functioning, and number of participants with at least one adverse effect. However, there was a higher risk for relapse and dropouts, and potentially for rehospitalisations, with dose reduction. Of note, the majority of the trials focused on relapse prevention rather potential beneficial outcomes on quality of life, functioning, and adverse effects, and in some studies there was rapid and substantial reduction of doses. Further well-designed RCTs are therefore needed to provide more definitive answers.

A systematic review of clinical guidelines on choice, dose, and duration of antipsychotics treatment in first- and multi-episode schizophrenia

Clinical guidelines provide evidence-based recommendations to regulate pharmacological treatment of psychotic disorders. However, the quality of evidence, country of origin, and publication dates of such guidelines vary, which leads to discrepancies between recommendations. This systematic review aimed to examine consensus and disparities between clinical recommendations on the choice, dose, and duration of antipsychotic treatment for first- and multi-episode schizophrenia patients. A literature search through The Cochrane Library, Embase, Medline, PsycINFO, PubMed, Scopus, Web of Sciences, and relevant bibliographies revealed 24 guidelines that met the inclusion criteria. The guidelines indicated mostly consistent recommendations regarding the optimal dose range of antipsychotics, while guidance with regards to the choice and duration of treatment remains somewhat controversial. Current trends in guidelines emphasize that there is simply no 'one-size-fits-all' method to manage schizophrenia patients. Further research is needed not only to address discrepancies between guidelines, but also to justify the gap between theory and practice.

Dose reduction of high-dose first-generation antipsychotics or switch to ziprasidone in long-stay patients with schizophrenia: A 1-year double-blind randomized clinical trial

Long-stay patients with severe schizophrenia are frequently treated with high doses of first-generation antipsychotics (FGA). Dose reduction or switching to ziprasidone may reduce the severity of negative symptoms and side effects. We investigated in a randomized double-blind trial whether a dose-reduction strategy to achieve an adequate dose of a FGA (5 mg/day haloperidol equivalents, n = 24) or switching to ziprasidone (160 mg/day, n = 24) in treatment resistant patients would decrease negative symptoms after 1 year of treatment. We found that negative symptoms did not change significantly in either condition. Positive symptoms, excited symptoms, and emotional distress worsened over time with ziprasidone, resulting in a significant difference between conditions in favour of FGA dose reduction. Relapse and treatment failure, defined as a prolonged or repeated relapse, occurred more often with ziprasidone than with FGA (45.8% versus 20.8%, and 25.0% versus 16.7%, respectively). Treatment with ziprasidone was superior for extrapyramidal symptoms. Our study establishes that lowering high FGA doses to an equivalent of 5 mg/day haloperidol or switching to ziprasidone is feasible in the vast majority of patients but does not improve negative or other symptoms. Neither FGA dose reduction nor switching to ziprasidone is an adequate alternative to clozapine for long-stay patients with severe treatment resistant schizophrenia.

Antipsychotic dosing: found in translation

In the field of schizophrenia research, as in other areas of psychiatry, there is a sense of frustration that greater advances have not been made over the years, calling into question existing research strategies. Arguably, many purported gains claimed by research have been "lost in translation," resulting in limited impact on diagnosis and treatment in the clinical setting. There are exceptions; for example, we would argue that different lines of preclinical and clinical research have substantially altered how we look at antipsychotic dosing. While this story remains a work in progress, advances "found in translation" have played an important role. Detailing these changes, the present paper speaks to a body of evidence that has already shifted clinical practice and raises questions that may further alter the manner in which antipsychotics have been administered over the last 6 decades.

William T. Carpenter Jr: 35 years of clinical trials

William T. Carpenter Jr has had a major impact on the design and conduct of clinical trials in schizophrenia. His contributions range from the decisive evaluation of the efficacy of hemodialysis to the development of novel approaches to evaluate new treatments for cognitive impairments and negative symptoms. He has developed innovative dosage reduction strategies. He has led efforts to focus drug development on those illness components that are not responsive to antipsychotic treatment. He has emphasized throughout his career the use of translational science to provide the conceptual framework for clinical trial interventions. This article reviews highlights of his many contributions, with an emphasis on 3 areas: (1) dosage reduction studies; (2) the use of the domains of psychopathology to identify drug development targets; and (3) the use of translational science to guide new drug development.

"Breakthrough" dopamine supersensitivity during ongoing antipsychotic treatment leads to treatment failure over time

Antipsychotics often lose efficacy in patients despite chronic continuous treatment. Why this occurs is not known. It is known, however, that withdrawal from chronic antipsychotic treatment induces behavioral dopaminergic supersensitivity in animals. How this emerging supersensitivity might interact with ongoing treatment has never been assessed. Therefore, we asked whether dopamine supersensitivity could overcome the behavioral and neurochemical effects of antipsychotics while they are still in use. Using two models of antipsychotic-like effects in rats, we show that during ongoing treatment with clinically relevant doses, haloperidol and olanzapine progressively lose their efficacy in suppressing amphetamine-induced locomotion and conditioned avoidance responding. Treatment failure occurred despite high levels of dopamine D2 receptor occupancy by the antipsychotic and was at least temporarily reversible by an additional increase in antipsychotic dose. To explore potential mechanisms, we studied presynaptic and postsynaptic elements of the dopamine system and observed that antipsychotic failure was accompanied by opposing changes across the synapse: tolerance to the ability of haloperidol to increase basal dopamine and dopamine turnover on one side, and 20-40% increases in D2 receptor number and 100-160% increases in the proportion of D2 receptors in the high-affinity state for dopamine (D2(High)) on the other. Thus, the loss of antipsychotic efficacy is linked to an increase in D2 receptor number and sensitivity. These results are the first to demonstrate that "breakthrough" supersensitivity during ongoing antipsychotic treatment undermines treatment efficacy. These findings provide a model and a mechanism for antipsychotic treatment failure and suggest new directions for the development of more effective antipsychotics.

Adverse extrapyramidal effects in four horse given fluphenazine decanoate

CASE DESCRIPTION

4 racehorses were examined because of markedly abnormal behavior following administration of fluphenazine decanoate.

CLINICAL FINDINGS

Clinical signs included restlessness, agitation, profuse sweating, hypermetria, aimless circling, intense pawing and striking with the thoracic limbs, and rhythmic swinging of the head and neck alternating with episodes of severe stupor. Fluphenazine was detected in serum or plasma from all 4 horses. The dose of fluphenazine decanoate administered to 3 of the 4 horses was within the range (25 to 50 mg) routinely administered to adult humans.

TREATMENT AND OUTCOME

In 2 horses, there was no response to IV administration of diphenhydramine hydrochloride, but the abnormal behavior in these 2 horses appeared to resolve following administration of benztropine mesylate, and both horses returned to racing. The other 2 horses responded to diphenhydramine administration. One returned to racing. The other was euthanized because of severe neurologic signs, respiratory failure, and acute renal failure.

CLINICAL RELEVANCE

Findings indicate that adverse extrapyramidal effects may occur in horses given fluphenazine decanoate. These effects appear to be unpredictable and may be severe and life threatening. Use of fluphenazine decanoate as an anxiolytic in performance horses is not permitted in many racing and horse show jurisdictions, and analytic procedures are now available to detect the presence of fluphenazine in serum or plasma.