The crossover approach to switching antipsychotics: what is the evidence?

Current and emerging long-acting antipsychotics for the treatment of schizophrenia

Introduction: In this review, the authors discuss the role of long-acting injectable antipsychotics (LAIs) for schizophrenia, focusing on the effectiveness and new perspectives introduced by such treatment strategy. Despite their promising pharmacokinetic features and their potential advantages in medication adherence, clinical outcomes, and medical costs, LAIs are not habitually presented as an option for patients, especially in the early phase of schizophrenia.Areas covered: This review explores the panorama of available LAIs for the treatment of schizophrenia, first-episode of psychosis, approved indications, medical costs, medication adherence, side effects, effectiveness and differences between first-generation (FGA)-LAIs and second-generation (SGA)-LAIs.Expert Opinion: LAIs differ in terms of specific indications, approved injection sites, needle size, injection volume, injection interval as well as potential drug-drug interactions, and commonly reported adverse reactions. The approved indications have expanded beyond schizophrenia to include bipolar and schizoaffective disorder. SGA-LAIs are often preferred to FGA-LAIs. FGA-LAIs although are less chosen in new patients due to the induction of cognitive and extrapyramidal side effects, even if, on the other hand, many SGA-LAIs are burden by hyperprolactinemia and weight gain. After a review of the available evidence, insight is provided into the potential and current therapeutic opportunities offered by LAI antipsychotic formulations.

From receptor pharmacology to improved outcomes: individualising the selection, dosing, and switching of antipsychotics

Determinants of antipsychotic selection and response include parameters of the primary disorder, psychiatric and physical comorbidities, past treatment effects, patient preferences, availability and acceptability of different treatments and formulations, as well as expected efficacy and safety. In the absence of consistent and sufficiently large efficacy differences among antipsychotics (except for clozapine in refractory patients), and in view of a greater focus on physical health, functional outcomes and quality of life, relatively more predictable differences in adverse events have become an important management consideration. Treatments are often selected because of a relatively lower propensity for extrapyramidal and sexual side effects, sedation, and, especially, the reduced development of cardiometabolic risk states and disorders. In this context, differences in receptor binding affinity, intrinsic activity and in the half life of antipsychotics are crucial to adopt adequate dosing and switching strategies. Dopamine rebound phenomena can occur when the level of dopamine blockade is not kept relatively constant during the switch process. This can happen when the new antipsychotic is underdosed or not fully absorbed, the switch is too abrupt from an antipsychotic with a short half life to one with a much longer half life, or when a dopamine antagonist is switched too fast to an antipsychotic with markedly less dopamine affinity or to a partial dopamine agonist. Intra-switch destabilization can also occur when changing too quickly from antipsychotics with strong histaminergic and/or cholinergic blockade to ones with lower affinity to these receptors. Overlapping “plateau” switch strategies and transient co-treatment with calming medications, such as benzodiazepines, have emerged as potential solutions to these rebound phenomena that can complicate the early switch period. To optimize outcomes, antipsychotic treatment should be pharmacologically informed and measurement based, combining both acute and long-term management goals and balancing efficacy and adverse effect considerations.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: Updated recommendations from the British Association for Psychopharmacology

These updated guidelines from the British Association for Psychopharmacology replace the original version published in 2011. They address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting was held in 2017, involving experts in schizophrenia and its treatment. They were asked to review key areas and consider the strength of the evidence on the risk-benefit balance of pharmacological interventions and the clinical implications, with an emphasis on meta-analyses, systematic reviews and randomised controlled trials where available, plus updates on current clinical practice. The guidelines cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. It is hoped that the practice recommendations presented will support clinical decision making for practitioners, serve as a source of information for patients and carers, and inform quality improvement.

Immediate vs Gradual Discontinuation in Antipsychotic Switching: A Systematic Review and Meta-analysis

Background

Antipsychotic switching is routine in clinical practice, although it remains unclear which is the preferable switching method: immediate discontinuation of the current antipsychotic or a gradual tapering approach. The first strategy has been implicated in rebound/withdrawal symptoms and emergence/exacerbation of symptoms, whereas the gradual approach is thought to pose a risk of additive or synergistic side effects if employed in the context of a crossover approach.

Methods

MEDLINE, Embase, and Cochrane Central Register of Controlled Trials were systematically searched. Randomized controlled trials examining immediate vs gradual antipsychotic discontinuation in antipsychotic switching in patients with schizophrenia and/or schizoaffective disorder were selected. Data on clinical outcomes, including study discontinuation, psychopathology, extrapyramidal symptoms, and treatment-emergent adverse events, were extracted.

Results

A total of 9 studies involving 1416 patients that met eligibility criteria were included in the meta-analysis. No significant differences in any clinical outcomes were found between the 2 approaches (all Ps > .05). Sensitivity analyses revealed that the findings remained unchanged in the studies where switching to aripiprazole was performed or where immediate initiation of the next antipsychotic was adopted, while some significant differences were observed in switching to olanzapine or ziprasidone.

Conclusions

These findings indicate that either immediate or gradual discontinuation of the current antipsychotic medication represents a viable treatment option. Clinicians are advised to choose an antipsychotic switching strategy according to individual patient needs. This said, immediate discontinuation may be advantageous both for simplicity and because a stalled cross-titration process in antipsychotic switching could end up in antipsychotic polypharmacy.

Dosing and switching of paliperidone ER in patients with schizophrenia: recommendations for clinical practice

Many patients with schizophrenia receive long-term treatment with antipsychotic medication. Switching of antipsychotic medication due to lack of efficacy, tolerability issues, and partial/non-adherence is common. Despite this, consensus strategies for switching between antipsychotics are lacking. This manuscript provides practical recommendations for switching antipsychotic medication to ensure optimal management of patients with schizophrenia, with a particular focus on paliperidone extended release (ER). The authors drew on their clinical experience supported by detailed discussion of literature describing antipsychotic switching techniques and strategies and findings from paliperidone ER clinical trials. Antipsychotic switching strategies should be individualized and take into consideration the pharmacokinetic (PK) and pharmacodynamic (PD) properties of the pre- and post-switch medication. The use of temporary concomitant medications may be appropriate in some scenarios. Abrupt withdrawal of pre-switch medication may be appropriate in some instances but carries a greater risk of rebound and withdrawal symptoms than other strategies. Cross-tapering is the method most widely used in clinical practice. Paliperidone ER can be initiated without dose titration. The EU SmPC recommended dose of paliperidone ER is 6 mg/day; but doses should be individualized within the approved range of 3-12 mg/day. Higher doses may be required due to insufficient efficacy of the previous antipsychotic or in patients with acute symptoms. Recently diagnosed patients, those with renal impairment, or patients who have previously experienced tolerability issues with other antipsychotics may require lower doses. When switching from risperidone, higher doses of paliperidone ER may be required compared with risperidone. When switching from antipsychotics that have sedative and/or significant anticholinergic activity, the pre-switch antipsychotic should be tapered off gradually. Antipsychotics with less sedating and little anticholinergic activity can be tapered off over a shorter period. Temporary concomitant sedative medication may be beneficial when switching from antipsychotics with relatively higher sedative propensities. Switching from another antipsychotic to paliperidone ER requires individualized switching strategies and dosing, dependent on the characteristics of the patient and the PK and PD properties of the pre-switch medication. Cross-tapering strategies should be considered as a means of reducing the risk of rebound and withdrawal symptoms.

A retrospective study of antipsychotic drug switching in a pediatric population

BACKGROUND

Antipsychotic drugs can be used to help treat a wide variety of psychiatric disorders. However, specific antipsychotic drugs for any particular patient may need to be changed for a number of different reasons, including a lack of therapeutic efficacy and / or intolerance to medication side-effects. Drug switching may occur through a limited number of established patterns. The nature of these changes is not well characterized in youth, despite their frequent occurrence.

METHODS

A retrospective analysis of antipsychotic drug switches was conducted on patients who had been admitted as inpatients to a tertiary care child and adolescent psychiatric institute. PharmaNet (a large, central administrative database) records of all medications prescribed in the 52 weeks prior to admission, and then between admission and discharge, were analyzed for switching patterns. Additional data regarding diagnoses were obtained from medical chart review.

RESULTS

Patients represented a diagnostically heterogeneous population, and almost all antipsychotic drugs were administered off-label. In the one year prior to and during admission to the hospital, a total of 31 out of 139 patients switched antipsychotic drugs. The frequency of switching increased closer to the time of admission, and the proportional rate of switching was even higher during hospital stay. The most common switch was from risperidone to quetiapine. Our analysis identified three main patterns of drug switching, all occurring with similar frequency: titrated drug switches, abrupt drug switches and concurrent drug administration.

CONCLUSIONS

The present study indicates that antipsychotic drug switching in youth may be relatively common, particularly in the year prior to hospitalization. No specific manner of drug switching predominates. This study also demonstrates the feasibility of using large administrative databases to characterise switching patterns in youth.

Withdrawal symptoms and rebound syndromes associated with switching and discontinuing atypical antipsychotics: theoretical background and practical recommendations

With the widespread use of atypical or second-generation antipsychotics, switching treatment has become current practice and more complicated, as the pharmacological profiles of these agents differ substantially despite their similarity in being 'atypical'. All share the ability to block dopamine D₂ receptors, and most of them also block serotonin 5-HT2A receptors. Apart from these common features, some atypical antipsychotics are also able to block or stimulate other dopamine or serotonin receptors, as well as histaminergic, muscarinergic or adrenergic receptors. As a result of the varying receptor affinities, in switching or discontinuing compounds several possible pitfalls have to be considered, including the occurrence of withdrawal and rebound syndromes. This article reviews the pharmacological background of functional blockade or stimulation of receptors of interest in regard to atypical antipsychotics and the implicated potential withdrawal and rebound phenomena. A MEDLINE search was carried out to identify information on withdrawal or rebound syndromes occurring after discontinuation of atypical antipsychotics. Using the resulting literature, we first discuss the theoretical background to the functional consequences of atypical antipsychotic-induced blockade or stimulation of neurotransmitter receptors and, secondly, we highlight the clinical consequences of this. We then review the available clinical literature on switching between atypical antipsychotics, with respect to the occurrence of withdrawal or rebound symptoms. Finally, we offer practical recommendations based on the reviewed findings. The systematic evaluation of withdrawal or rebound phenomena using randomized controlled trials is still understudied. Knowledge of pharmacological receptor-binding profiles may help clinicians in choosing adequate switching or discontinuation strategies for each agent. Results from large switching trials indicate that switching atypical antipsychotics can be performed in a safe manner. Treatment-emergent adverse events during or after switching are not always considered to be, at least in part, associated with the pre-switch antipsychotic. Further studies are needed to substantiate the evidence gained so far on different switching strategies. The use of concomitant medication, e.g., benzodiazepines or anticholinergic drugs, may help to minimize symptoms arising from the discontinuation or switching of antipsychotic treatment.

A global measure to assess switching antipsychotic medications in the treatment of schizophrenia

OBJECTIVES

It is common practice to switch antipsychotic medications in the treatment of patients with schizophrenia to enhance clinical efficacy and/or reduce drug-related side effects. The conventional Clinical Global Impression (CGI) of severity scale is a well-understood measure to track switching effects but does not differentiate between the severity of clinical symptoms and the impact of side effects..

METHODS

We developed a CGI-switch instrument that contains distinct global severity scales for clinical efficacy, safety and/or tolerability, and a third unified (integrated) CGI severity score to assess these interrelated assessments. An integrated Clinical Global Impression of Change was also created to assess global clinical change relative to the initiation of treatment.

RESULTS

Interrater reliability conducted as part of a rater-training program for a clinical study (Novartis protocol CIL0522D; clinitrials.gov identifier: CT01207414) revealed high interrater agreement (Cronbach's alpha = 0.945). Data were collected from 1066 CGI assessments during the course of the trial. CGI raters easily grasped the utility of the instrument. The distinction made between efficacy and safety/tolerability facilitated serial tracking of each condition during the course of treatment.

CONCLUSION

The modified CGI-switch instrument is a simple, reliable, and practical metric to assess the benefits, if any of switching antipsychotic medications in patients with schizophrenia.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: recommendations from the British Association for Psychopharmacology

These guidelines from the British Association for Psychopharmacology address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting, involving experts in schizophrenia and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from the participants and interested parties, and cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. The practice recommendations presented are based on the available evidence to date, and seek to clarify which interventions are of proven benefit. It is hoped that the recommendations will help to inform clinical decision making for practitioners, and perhaps also serve as a source of information for patients and carers. They are accompanied by a more detailed qualitative review of the available evidence. The strength of supporting evidence for each recommendation is rated.

Antipsychotic switching for people with schizophrenia who have neuroleptic-induced weight or metabolic problems

BACKGROUND

Weight gain is common for people with schizophrenia and this has serious implications for a patient's health and well being. Switching strategies have been recommended as a management option.

OBJECTIVES

To determine the effects of antipsychotic medication switching as a strategy for reducing or preventing weight gain and metabolic problems in people with schizophrenia.

SEARCH STRATEGY

We searched key databases and the Cochrane Schizophrenia Group's trials register (January 2005 and June 2007), reference sections within relevant papers and contacted the first author of each relevant study and other experts to collect further information.

SELECTION CRITERIA

All clinical randomised controlled trials comparing switching of antipsychotic medication as an intervention for antipsychotic induced weight gain and metabolic problems with continuation of medication and/or other weight loss treatments (pharmacological and non pharmacological) in people with schizophrenia or schizophrenia-like illnesses.

DATA COLLECTION AND ANALYSIS

Studies were reliably selected, quality assessed and data extracted. For dichotomous data we calculated risk ratio (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis, based on a fixed-effect model. The primary outcome measures were weight loss, metabolic syndrome, relapse and general mental state.

MAIN RESULTS

We included four studies for the review with a total of 636 participants. All except one study had a duration of 26 weeks or less. There was a mean weight loss of 1.94 kg (2 RCT, n = 287, CI -3.9 to 0.08) when switched to aripiprazole or quetiapine from olanzapine. BMI also decreased when switched to quetiapine (1 RCT, n = 129, MD -0.52 CI -1.26 to 0.22) and aripiprazole (1 RCT, n = 173, RR 0.28 CI 0.13 to 0.57) from olanzapine.Fasting blood glucose showed a significant decrease when switched to aripiprazole or quetiapine from olanzapine. (2 RCT, MD -2.53 n = 280 CI -2.94 to -2.11). One RCT also showed a favourable lipid profile when switched to aripiprazole but these measures were reported as percentage changes, rather than means with standard deviation.People are less likely to leave the study early if they remain on olanzapine compared to switching to quetiapine or aripiprazole.There was no significant difference in outcomes of mental state, global state, and adverse events between groups which switched medications and those that remained on previous medication. Three different switching strategies were compared and no strategy was found to be superior to the others for outcomes of weight gain, mental state and global state.

AUTHORS' CONCLUSIONS

Evidence from this review suggests that switching antipsychotic medication to one with lesser potential for causing weight gain or metabolic problems could be an effective way to manage these side effects, but the data were weak due to the limited number of trials in this area and small sample sizes. Poor reporting of data also hindered using some trials and outcomes. There was no difference in mental state, global state and other treatment related adverse events between switching to another medication and continuing on the previous one. When the three switching strategies were compared none of them had an advantage over the others in their effects on the primary outcomes considered in this review. Better designed trials with adequate power would provide more convincing evidence for using medication switching as an intervention strategy.

Benefits of switching women schizophrenic patients to aripiprazole: a case study and brief review of the literature

Hyperprolactinemia, an adverse side-effect of the use of typical and some atypical antipsychotics, has both acute and chronic clinical consequences. When observed in schizophrenic patients, it may be treated by switching the patient to an antipsychotic agent with a lower liability for the induction of hyperprolactinemia. The effects of substituting aripiprazole for other antipsychotic agents on schizophrenic patients with antipsychotic-induced hyperprolactinemia have been previously reported in several studies. Many studies have also noted that aripiprazole can sometimes lead to increases in psychotic symptoms, especially in the period immediately following the switch or when aripiprazole is combined with a dopamine antagonist. Here, we report observations on five female patients who were experiencing symptomatic hyperprolactinemia and psychotic exacerbation while on antipsychotic treatment, yet improved in both conditions after being switched to aripiprazole monotherapy. We also provide a brief review of the existing studies that report the results of switching patients from other antipsychotics to aripiprazole.

Switching from conventional antipsychotics to ziprasidone: a randomized, open-label comparison of regimen strategies

In clinical psychopharmacology, the optimal method of switching from treatment A to treatment B with regard to efficacy and tolerability is an important area of study. We investigated the effects on efficacy and tolerability of switching patients from conventional antipsychotics to ziprasidone. This was a 6-week open-label, randomized study of 54 patients with persistent schizophrenia or schizoaffective disorder. Patients received ziprasidone 40 mg BID for 2 days, with titration up to 80 mg BID thereafter. The switch from conventional antipsychotics to ziprasidone was achieved using one of three discrete schedules: (1) abrupt discontinuation of conventional antipsychotics on day 1; (2) fast taper-50% of conventional antipsychotic dosage on days 1 through 7, followed by discontinuation and (3) slow taper-100% of conventional antipsychotic dosage on days 1 and 2, followed by 50% on days 3 through 7, then discontinuation. We found some evidence that the slow-taper strategy was associated with greater reductions in BPRS total scores early in the study compared to the other two strategies. However, these differences did not remain significant at endpoint, suggesting that there was no overall difference between the strategies.

Switching and combining antipsychotics

Pharmacologic knowledge can inform clinical decision-making, particularly the dosing and switching decisions made with antipsychotics. Of relevance are the pharmacokinetic (what does the body do to the drug) and the pharmacodynamic (what does the drug do to the body) properties of antipsychotics.

The goal of antipsychotic dosing is to achieve sufficient dopa-mine blockade in areas where dopamine excess can lead to psychosis, mania, or aggression. Using positron emission topography, one investigation showed that response rates were considerably higher in patients who achieved >65% striatal dopamine blockade. Conversely, striatal dopamine blockade >80% predicted the emergence of extrapyramidal symptoms (EPS) or akathisia.

There is, however, considerable intra-individual variability in achieving the desired 60% to 80% striatal dopamine blockade. Such variability is likely due to inter-individual differences in the absorption, distribution, metabolism and elimination of medications. At the same time, antipsychotics themselves differ in their general pharmacokinetic profiles. For example, ziprasidone absorption is ~50% less when ingested on an empty stomach than when taken with a meal; the degree of absorption depends on the caloric content, while the fat content is not relevant.

FDG-PET and MRI imaging of the effects of sertindole and haloperidol in the prefrontal lobe in schizophrenia

Sertindole, a 2nd generation antipsychotic with low movement disorder side effects, was compared with haloperidol in a 6-week crossover study. Fifteen patients with schizophrenia (mean age=42.6, range=22-59, 11 men and 4 women) received sertindole (12-24 mg) or haloperidol (4-16 mg) for 6 weeks and then received a FDG-PET scan and an anatomical MRI. Patients were then crossed to the other treatment and received a second set of scans at week 12. Dose was adjusted by a physician blind to the medication type. Brodmann areas were identified stereotaxically using individual MRI templates applied to the coregistered FDG-PET image. Sertindole administration was associated with higher dorsolateral prefrontal cortex metabolic rates than haloperidol and lower orbitofrontal metabolic rates than haloperidol. This effect was greatest for gray matter of the dorsolateral Brodmann areas 8, 9, 10, 44, 45, and 46. Patients were further contrasted with an approximately age and sex-matched group of 33 unmedicated patients with schizophrenia and with a group of 55 normal volunteers. Sertindole administration was associated with greater change toward normal values and away from the values found in the unmedicated comparison group for dorsolateral prefrontal cortex gray matter and white matter underlying medial prefrontal and cingulate cortex. These results are consistent with the low motor side-effect profile of sertindole, greater improvement on prefrontal cognitive tasks with sertindole than haloperidol, and with the tendency of 2nd generation antipsychotic drugs to have greater frontal activation than haloperidol.

Efficacy and tolerability of switching to ziprasidone from olanzapine, risperidone or haloperidol: an international, multicenter study

To compare the effectiveness of a switch from haloperidol (N=99), olanzapine (N=82), or risperidone (N=104) to 12 weeks of treatment with 80-160 mg/day ziprasidone in patients with stable schizophrenia or schizoaffective disorder. Stable outpatients with persistent symptoms or troublesome side effects were switched using one of three 1-week taper/switch strategies as determined by the investigator. Efficacy was assessed using the Brief Psychiatric Rating Scale score, Clinical Global Impression, Positive and Negative Symptom Scale, Montgomery-Asberg Depression Rating Scale, and the Global Assessment of Functioning Scale, and tolerability by using standard measures of weight change, extrapyramidal symptoms, and laboratory findings. Suboptimal efficacy was the primary reason for switching. The preferred switch strategy was immediate discontinuation, and the preferred dosing regimen was 120 mg/day. Completer rates were 68, 60, and 86% in the haloperidol, risperidone, and olanzapine pre-switch groups, respectively. At week 12, a switch to ziprasidone resulted in statistically significant improvement from baseline on the Brief Psychiatric Rating Scale score, Clinical Global Impression-Improvement, Positive and Negative Symptom Scale, and Global Assessment of Functioning scales, reduction in extrapyramidal symptoms and a neutral impact on metabolic parameters. Switch from olanzapine and risperidone resulted in weight reduction and from haloperidol in some weight increase. In conclusion, oral ziprasidone of 80-160 mg/day with food was a clinically valuable treatment option for stable patients with schizophrenia or schizoaffective disorder experiencing suboptimal efficacy or poor tolerability with haloperidol, olanzapine, or risperidone.

Antipsychotic Drug Treatment for Patients with Schizophrenia: Theoretical Background, Clinical Considerations and Patient Preferences

The cornerstone in treatment of psychosis is antipsychotic drugs. Treatment options have increased over the years; newer antipsychotic drugs with a proposed increased efficacy regarding negative and cognitive symptoms, but also a shift in side-effects from neurological side-effects to metabolic side-effects have arisen as the new challenge. The basis of successful pharmacological treatment is a fundamental understanding of the mechanisms of action, the desired effects and side-effects of antipsychotic drugs, a good relationship with the patient and a thorough monitoring of the patient before and during treatment. The clinically relevant aspects of antipsychotic drug treatment are reviewed; mechanism of antipsychotic drug action, clinical considerations in treatment, switching antipsychotic drugs, polypharmacy, safety and patient preference.

Immediate versus gradual suspension of previous treatments during switch to aripiprazole: results of a randomized, open label study

The aim of the present work was to investigate possible differences in terms of efficacy and tolerability between different switching options to aripiprazole. 77 subjects were randomly assigned to (1) administration of aripiprazole (10 mg) with simultaneous discontinuation of current antipsychotic; (2) administration of aripiprazole (10 mg) and tapering off current antipsychotic over 4 weeks with half dose after the first 2 weeks; (3) administration of aripiprazole (10 mg) and tapering off current antipsychotic over 6 weeks with half dose after the first 2 weeks. Efficacy assessments included CGI-S, CGI-I, BPRS and SANS. Safety assessments included SAS, BAS and AIMS. Severity of symptoms significantly decreased from baseline over the 12 weeks of treatment. Patients switched to aripiprazole with immediate discontinuation of the previous antipsychotic showed an increase of symptoms' severity at week 1. However, severity of side effects did not overall change significantly during the 12-weeks follow-up. Previous treatment's tapering off strategy for switching patients to aripiprazole could be preferable as compared to abrupt discontinuation, in order to prevent early worsening of symptoms and premature discontinuation of treatment, though this results has to be considered with caution given the limitations of the study.

The risks and benefits of switching antipsychotics: a case study approach

PURPOSE

Progression of metabolic illness in a patient with schizophrenia who was stabilized on an atypical antipsychotic is described using a case study framework. Risks and benefits of staying on current treatment versus switching to another agent and switching strategies are described.

CONCLUSIONS

Switching an antipsychotic with more favorable side effects may improve metabolic parameters if other weight loss strategies have failed. Switching or stopping medications too quickly may exacerbate psychiatric symptoms. There is little evidence to support which is the best switching strategy.

PRACTICE IMPLICATIONS

The psychiatric mental health nurse practitioner carries a significant responsibility of discussing risks and benefits of switching and closely monitoring the patient during a switch of medications. Ensuring that the patient decides and agrees upon the treatment plan will improve the overall outcome.

Does switching to a new antipsychotic improve outcomes? Data from the CATIE Trial

PURPOSE

Previous analysis of data from CATIE showed that patients randomly assigned to switch to a new medication were more likely to discontinue study drug than those who stayed on the medication they had been taking prior to randomization. This study addresses additional outcomes measures evaluating symptoms, neurocognition, quality of life, neurological side effects, weight, and health costs. First, considering patients randomized to olanzapine or risperidone, outcomes among patients who had been on the drug to which they were randomized prior to CATIE (N=129 "stayers") were compared to outcomes of those who switched to either of these two drugs (N=269 "switchers"). A second set of analyses considered patients on baseline monotherapy with olanzapine (N=297); risperidone (N=252) or quetiapine (n=87) and compared those randomly assigned to stay on each of these medications with those assigned to switch to any of the other five phase 1 medications in CATIE. In mixed models of each outcome the independent variable of primary interest represented stay vs. switch, with multivariate adjustment for potential confounding factors.

RESULTS

With one exception, there were no significant differences between stayers and switchers on any outcome measure in either set of analyses. The exception was that, in the second set of analyses, patients who stayed on olanzapine showed greater weight gain than those who switched from olanzapine to other drugs.

CONCLUSION

Switching to a new medication yielded no advantage over staying on the previous medication. Staying on olanzapine was associated with greater weight gain.

Commentary on strategies for switching antipsychotics

Both the new generation of antipsychotics and the more traditional antipsychotic drugs produce an important and meaningful improvement in patients with schizophrenia, but most patients are neither cured nor free of symptoms. As a consequence, it is common to switch from one drug to another in the hope of obtaining a better response. All antipsychotic drugs produce some side effects, so switching can also be a tolerance issue. There are reports in the literature on the tactics of switching: abrupt discontinuation, cross tapering, starting a patient on a new drug while continuing with the old drug until the new drug has reached a steady state, or some variation on these tactics. In this issue, Ganguli et al. have carried out a randomized switching study, the data from which indicates the tactics that might be optimal. We put this paper into context, provide a critique and describe indications for switching.

Time-dependent cognitive deficits associated with first and second generation antipsychotics: cholinergic dysregulation as a potential mechanism

Although cognitive dysfunction is considered one of the more debilitating symptoms of schizophrenia, there is a fundamental gap in our knowledge of how the primary pharmacologic treatments of this disease, first- and second-generation antipsychotics (FGAs and SGAs, respectively), affect cognition, particularly over extended periods of time. Moreover, it has been known for decades that chronic treatment with FGAs can lead to imbalances in cholinergic function in the striatum that result in movement disorders; however, there is a growing body of evidence to suggest that both FGAs and SGAs can lead to cholinergic alterations in brain areas more traditionally considered as memory-related, such as cortical and hippocampal regions. Data from our laboratories in rodents indicate that some SGAs (if administered for sufficient periods of time) can be associated with impairments in memory-related task performance as well as alterations in the cholinergic enzyme choline acetyltransferase, the vesicular acetylcholine transporter, and nicotinic (alpha(7)) and muscarinic (M(2)) acetylcholine receptors. Given the well documented importance of central cholinergic function to information processing and cognitive function, it is important that the mechanisms for such chronic antipsychotic effects be identified. In this review, two potential mechanisms for long-term antipsychotic-related cholinergic alterations in the central nervous system are discussed: 1) antipsychotic antagonist activity at dopaminergic-D(2) receptors on cholinergic neurons and 2) antipsychotic effects on neurotrophins that support cholinergic neurons, such as nerve growth factor and brain derived growth factor. Novel strategies to optimize the therapeutics of schizophrenia and maintain cognitive function via adjunctive cholinergic compounds and antipsychotic crossover approaches are also discussed.

Interventions to reduce weight gain in schizophrenia

BACKGROUND

Weight gain is common for people with schizophrenia and this has serious implications for health and well being.

OBJECTIVES

To determine the effects of both pharmacological (excluding medication switching) and non pharmacological strategies for reducing or preventing weight gain in people with schizophrenia.

SEARCH STRATEGY

We searched key databases and the Cochrane Schizophrenia Group's trials register (April 2006), reference sections within relevant papers, hand searched key journals, and contacted the first author of each relevant study and other experts to collect further information.

SELECTION CRITERIA

We included all clinical randomised controlled trials comparing any pharmacological or non pharmacological intervention for weight gain (diet and exercise counselling) with standard care or other treatments for people with schizophrenia or schizophrenia-like illnesses.

DATA COLLECTION AND ANALYSIS

We reliably selected, quality assessed and extracted data from studies. As weight is a continuous outcome measurement, weighted mean differences (WMD) of the change from baseline were calculated. The primary outcome measure was weight loss.

MAIN RESULTS

Twenty-three randomised controlled trials met the inclusion criteria for this review. Five trials assessed a cognitive/behavioural intervention and eighteen assessed a pharmacological adjunct. In terms of prevention, two cognitive/behavioural trials showed significant treatment effect (mean weight change) at end of treatment (n=104, 2 RCTs, WMD -3.38 kg CI -4.2 to -2.0). Pharmacological adjunct treatments were significant with a modest prevention of weight gain (n=274, 6 RCTs, WMD - 1.16 kg CI -1.9 to -0.4). In terms of treatments for weight loss, we found significantly greater weight reduction in the cognitive behavioural intervention group (n=129, 3 RCTs, WMD -1.69 kg CI -2.8 to -0.6) compared with standard care.

AUTHORS' CONCLUSIONS

Modest weight loss can be achieved with selective pharmacological and non pharmacological interventions. However, interpretation is limited by the small number of studies, small sample size, short study duration and by variability of the interventions themselves, their intensity and duration. Future studies adequately powered, with longer treatment duration and rigorous methodology will be needed in further evaluating the efficacy and safety of weight loss interventions for moderating weight gain. At this stage, there is insufficient evidence to support the general use of pharmacological interventions for weight management in people with schizophrenia.

Using aripiprazole to resolve antipsychotic-induced symptomatic hyperprolactinemia: a pilot study

OBJECTIVE

To assess the effectiveness of substituting aripiprazole for other antipsychotic drugs taken by stable schizophrenic patients suffering from antipsychotic agent-induced symptomatic hyperprolactinemia.

METHODS

Seven female schizophrenic patients with symptomatic hyperprolactinemia (167.6+/-58.0 microg/L) were recruited to take part in an 8-week open label trial of aripiprazole (10-20 mg/day) as a replacement for amisulpride or risperidone. Efficacy was assessed via PANSS and CGI-I scores. Serum prolactin levels were measured at baseline, week 4, and week 8. Data were collected from November, 2004 to May, 2005.

RESULTS

At the end of weeks 4, serum prolactin levels were normalized (8.8+/-5.5 microg/L) and hyperprolactinemic symptoms were resolved in all patients. However, aripiprazole treatment was discontinued within 6 weeks for 2 of the 7 subjects due to aggravated auditory hallucinations.

CONCLUSION

Results from this admittedly small-scale open-label study indicate that switching to aripiprazole may be useful for resolving antipsychotic-induced hyperprolactinemia and associated symptoms.