Clozapine in tardive dyskinesia

Sustained Treatment Response and Global Improvements With Long-term Valbenazine in Patients With Tardive Dyskinesia

PURPOSE/BACKGROUND

Using data from KINECT® 4, a phase 3, 48-week study of valbenazine, post hoc analyses were conducted to assess long-term outcomes that are relevant to the real-world management of tardive dyskinesia (TD).

METHODS/PROCEDURES

Post hoc analyses of the participants of the KINECT 4 study who completed 48 weeks of open-label valbenazine (40 or 80 mg) treatment were conducted. Valbenazine effects on TD were evaluated using the Abnormal Involuntary Movement Scale (AIMS), Clinical Global Impression of Change-TD (CGI-TD), and Patient Global Impression of Change (PGIC).

FINDINGS/RESULTS

Of 103 participants completing 48 weeks of treatment, 55% experienced clinically meaningful improvement (defined as ≥2-point reduction in AIMS total score [sum of items 1 - 7, evaluated by site raters]) by week 4; at week 48, 97% met this threshold. The percentage of completers who achieved AIMS total score response thresholds of ≥10% to ≥90% increased over time, with 86% of completers reaching ≥50% improvement. Of the 40 (39%) completers with AIMS ≥50% response at week 8, 38 (95%) sustained this response at week 48; 81% of those who did not meet this threshold at week 8 had achieved it by week 48. At week 48, more than 85% of completers achieved CGI-TD and PGIC ratings of "much improved" or "very much improved."

IMPLICATIONS/CONCLUSIONS

The majority of participants who completed 48 weeks of treatment with once-daily valbenazine experienced substantial clinically meaningful and sustained TD improvements. These findings indicate that valbenazine can be a highly effective long-term treatment in patients with TD.

The introduction of clozapine at the Nathan Kline Institute in New York and its long-term consequences

Nathan S. Kline was a pioneer in psychopharmacology in the United States (US). In 1952, Kline started a research unit at Rockland State Hospital, New York. Kline brought clozapine from Switzerland since it was not yet available in the US. At Rockland State Hospital, George Simpson had conducted antipsychotic trials and had developed scales to assess movement disorders. In 1974, Simpson published the first US clozapine trial. In 1978, he published on 1) the effect of clozapine on tardive dyskinesia and 2) high plasma clozapine concentrations in two patients with seizures. His experience of clozapine withdrawal symptoms in his first 2 trials led in the future to more articles in this area. In Philadelphia, Simpson designed a double-blind randomized clinical trial (RCT) with 3 doses (100, 300 and 600 mg/day) which was published in 1999. From the 50 patients started on the RCT, 47 provided repeated plasma clozapine concentrations every other week of the RCT. This rich database of plasma clozapine concentrations under controlled conditions has contributed to many of the advances in clozapine pharmacokinetics in the last 5 years including: 1) obesity can be associated with clozapine poor metabolism (PM) status, 2) a clozapine ultrarapid metabolizer (UM) with a minimum therapeutic dose of 1591 mg/day, 3) a case of clozapine intoxication dropped from the RCT due to pneumonia, 4) cases of increased plasma concentrations during clozapine-induced fever, 5) the possibility that African-Americans may need higher clozapine doses than those of European ancestry, and 6) three indices of non-adherence.

A systematic review on the use of clozapine in treatment of tardive dyskinesia and tardive dystonia in patients with psychiatric disorders

RATIONALE

Though clozapine is recommended for treatment of tardive dyskinesia (TD) relating to the use of antipsychotic medications, studies comprehensively investigating the treatment effect of clozapine on TD are still limited.

OBJECTIVES

This review examines the effectiveness of clozapine as an intervention for tardive dyskinesia and dystonia in patients with all psychiatric conditions. Effectiveness of clozapine, duration to exert the effect and dosage used were also analysed.

METHODS

A search in the PubMed, PsycINFO and clinicaltrials databases was performed, using the search terms "Clozapine" AND "dyskinesia" OR "dystonia". Full-text articles that reported the use of clozapine to treat abnormal involuntary movements and were written in English were included.

RESULTS

A total of 48 studies were identified, of which 13 were clinical trials and 35 were case reports. Significant improvement was seen in 86.7% of patients with schizophrenia spectrum disorders (average dose of clozapine = 355 mg/day) and 93% of patients with other psychiatric disorders (average dose of clozapine = 152.5 mg/day). Patients with other psychiatric diagnoses had faster improvement than the patients with schizophrenia spectrum disorders. Variation in improvements and dosage were also seen in the clinical trials.

CONCLUSION

Results suggested an overall effectiveness of clozapine in the treatment of TD for patients with a range of psychiatric conditions. Different response time and clozapine dosage were seen in patients with different psychiatric conditions, suggesting different treatment protocols are required for different conditions. Most of the studies identified are of inadequate qualities, highlighting the need for high quality studies to provide clearer evidence.

A new era in the diagnosis and treatment of tardive dyskinesia

Tardive dyskinesia (TD) is a heterogeneous, hyperkinetic movement disorder induced by dopamine-receptor blocking agents that presents a unique challenge in the treatment of psychosis. Although acceptance of TD as a serious consequence of antipsychotic treatment was resisted initially, subsequent research by many investigators in psychopharmacology contributed to a rich store of knowledge on many aspects of the disorder. While basic neuroscience investigations continue to deepen our understanding of underlying motor circuitry, past trials of potential treatments of TD focusing on a range of theoretical targets were often inconclusive. Development of newer antipsychotics promised to reduce the risk of TD compared to older drugs, but their improved tolerability unexpectedly enabled an expanding market that paradoxically both increased the absolute number of patients at risk and diminished attention to TD which was relegated to legacy status. Fortunately, development and approval of novel vesicular monoamine transporter inhibitors offered evidence-based symptomatic treatment of TD for the first time and rekindled interest in the disorder. Despite recent progress, many questions remain for future research including the mechanisms underlying TD, genetic predisposition, phenomenological diversity, whether new cases are reversible, how to implement best practices to prevent and treat TD, and whether the development of novel antipsychotics free of the risk of TD is attainable. We owe our patients the aspirational goal of striving for zero prevalence of persistent symptoms of TD in anyone treated for psychosis.

Reducing the Risk of Withdrawal Symptoms and Relapse Following Clozapine Discontinuation-Is It Feasible to Develop Evidence-Based Guidelines?

Clozapine is the only antipsychotic that is effective in treatment-resistant schizophrenia. However, in certain clinical situations, such as the emergence of serious adverse effects, it is necessary to discontinue clozapine. Stopping clozapine treatment poses a particular challenge due to the risk of psychotic relapse, as well as the development of withdrawal symptoms. Despite these challenges for the clinician, there is currently no formal guidance on how to safely to discontinue clozapine. We assessed the feasibility of developing evidence-based recommendations for (1) minimizing the risk of withdrawal symptoms, (2) managing withdrawal phenomena, and (3) commencing alternatives treatment when clozapine is discontinued. We then evaluated the recommendations against the Appraisal of Guidelines for Research and Evaluation (AGREE) II criteria. We produced 19 recommendations. The majority of these recommendation were evidence-based, although the strength of some recommendations was limited by a reliance of studies of medium to low quality. We discuss next steps in the refinement and validation of an evidence-based guideline for stopping clozapine and identify key outstanding questions.

Valbenazine for the Treatment of Adults with Tardive Dyskinesia

PURPOSE OF REVIEW

This a comprehensive review of the literature regarding the use of Valbenazine in treating tardive dyskinesia. A primarily oral movement disorder induced by chronic exposure to certain classes of medications, tardive dyskinesia is often resistant to many therapeutic approaches. This review presents the background, evidence, and indications for the use of Valbenazine as a treatment option for this condition.

RECENT FINDINGS

Tardive dyskinesia is a disorder arising from long-term exposure to medications that blocked dopamine receptors, primarily antipsychotics. It is characterized by abnormal movements of the oral-buccal-lingual structures as well as associated pain and hypertrophy. Simply stopping the use of the dopamine blocking agents effectively alleviates the symptoms but is not always reliable hence the need for another therapeutic approach.Valbenazine is thought to function as a highly selective inhibitor of the VMAT2 vesicular monoamine transporter resulting in decreased availability of dopamine in the presynaptic cleft. This leads to decreased dopaminergic activation of the striatal motor pathway. The FDA approved Valbenazine in 2017 to treat tardive dyskinesia in adults and needs to be evaluated with existing therapeutic approaches.

SUMMARY

The chronic use of dopamine receptor blocking agents, most commonly antipsychotics, can lead to a movement disorder called tardive dyskinesia. Once symptom onset has occurred, these movement abnormalities can persist for years to permanently, depending on the speed and effectiveness of treatment. Valbenazine is a relatively newer option for the treatment of tardive dyskinesia in adults. Compared to other pharmaceutical agents, it is more selective and has limited toxicities making it an effective treatment regimen. However, further research, including additional direct comparison studies, should be conducted to fully evaluate this drug's usefulness.

Dystonia and leveraging oral pharmacotherapy

Dystonia is a clinically diverse disorder, characterized by sustained or intermittent muscle contractions causing abnormal and often repetitive movements and/or postures. Accurate clinical diagnosis is tantamount to effective dystonia management. Current guidelines in the treatments of dystonia, including oral therapy, are prescribed to improve symptoms and to restore functional capacity. Identifying treatable causes from co-existing phenomenologies is relevant to provide the most optimal and disease-specific medications. In other forms of dystonia, genetic factors may affect outcome. Moreover, proper selection of patients, early initiation of medications and customized drug titration are keys to increasing the chances of success when using oral therapies for dystonia. Treatment of dystonia primarily involves agents that target dopamine and acetylcholine receptors. Other drugs used include benzodiazepines, baclofen, antiepileptics, some antipsychotics drugs and antihistamine, with different levels of evidence of effectiveness. Unfortunately, most of the widely used drugs have low levels of evidence and are primarily based on anecdotal experiences. Finally, other adjunctive therapeutic strategies are often necessary to complement oral therapy.

Clozapine discontinuation withdrawal symptoms in schizophrenia

Clozapine is an atypical antipsychotic used in treatment-resistant schizophrenia. Whilst clozapine is highly effective, there are some clinical scenarios, such as the emergence of severe side effects, that necessitate its discontinuation. There is an emerging literature suggesting that discontinuing antipsychotics, in particular clozapine, can cause an array of withdrawal symptoms. We review the evidence for the existence of clozapine-induced withdrawal symptoms, and in particular focus on withdrawal-associated psychosis, cholinergic rebound, catatonia and serotonergic discontinuation symptoms. To date, there has been surprisingly little clinical guidance on how to minimise the likeliness of withdrawal symptoms in patients who are stopped on clozapine abruptly or gradually. We discuss the key outstanding questions in this area and why there is a need for guidance on the management of withdrawal symptoms associated with clozapine discontinuation.

Clozapine and tardive dyskinesia in patients with schizophrenia: A systematic review

BACKGROUND

It is commonly recommended that a switch to clozapine be implemented in the face of tardive dyskinesia, even if current treatment involves another "atypical" agent. However, reports do indicate clozapine carries a liability for tardive dyskinesia.

AIMS

This review sought to evaluate clozapine in relation to tardive dyskinesia in the context of available evidence.

METHODS

Medline, Embase, and PsycINFO databases were searched for studies published in English, using the keywords: clozapine AND tardive dyskinesia OR TD. References from major review articles were searched for additional relevant publications. Studies were included if they investigated: tardive dyskinesia in clozapine-treated patients diagnosed with schizophrenia spectrum disorders, and reported on two or more assessments of tardive dyskinesia severity measured by the Abnormal Involuntary Movement Scale; or clozapine's tardive dyskinesia liability.

RESULTS

In total, 513 unique citations were identified and 29 reports met the inclusion criteria. Thirteen studies suggest clozapine reduces dyskinetic symptoms over time (n=905 clozapine-treated participants); however, the minimum required dose and effect of withdrawal requires further investigation. The majority of reports which address clozapine's liability for tardive dyskinesia are case studies (11 of 14 reports, 79%), and clozapine was only the first-line treatment in one of the remaining three studies reporting treatment-emergent dyskinetic symptoms with clozapine in 12% of patients. No significant between-drug differences were identified comparing clozapine's risk to other atypical antipsychotics.

CONCLUSIONS

Research to date supports switching to clozapine for the purpose of reducing tardive dyskinesia risk and/or treating existing tardive dyskinesia, but prospective randomized controlled trials are necessary if we are to substantiate existing recommendations.

A case report of cholinergic rebound syndrome following abrupt low-dose clozapine discontinuation in a patient with type I bipolar affective disorder

BACKGROUND

Rebound cholinergic syndrome is a rare, but well known unwanted phenomenon occurring after abrupt clozapine discontinuation. There have been previous reported cases of cholinergic rebound in the literature; however, these reports described cholinergic rebound following cessation of high doses of clozapine in patients diagnosed with schizophrenia. Here, we report a case of rebound cholinergic syndrome and catatonia in a male patient three days after abrupt discontinuation of 50 mg of clozapine prescribed for type I bipolar affective disorder.

CASE PRESENTATION

A 66-year old male of Spanish origin, treated for type I bipolar affective disorder for 15 years and for Crohn disease, was brought to the emergency department because of a sudden onset of mutism, dysphagia and trismus. He was described catatonic and presented hypertension, tachycardia and tachypnea. His body temperature was normal and the laboratory tests were unremarkable at presentation. A head CT and an EEG were in the normal range. While reviewing his history, it appeared the he was on clozapine 50 mg a day, first introduced 2 months ago, during a previous hospitalization for a manic episode resistant to other mood stabilizers. For an unknown reason, the patient's psychiatrist stopped clozapine three days before the admission and replaced it by risperidone 5 mg and quetiapine 200 mg daily. A cholinergic rebound syndrome was then evoked. The patient's ability to speak recovered dramatically and fast after the intravenous administration of 2.5 mg of biperiden supporting the diagnosis. Risperidone and quetiapine were also stopped. The patient fully recovered in 20 days after the reintroduction of 50 mg of clozapine and 2.5 mg of biperiden daily.

CONCLUSIONS

This case report underscores that cholinergic rebound syndrome may occur in patients suffering from bipolar affective disorders, being on clozapine as a mood stabilizer. The low dose clozapine does not preclude severe manifestations of the phenomenon. Progressive tapering should therefore be adopted in any case.

Current treatment of tardive dyskinesia

Tardive dyskinesia (TD) is a common, iatrogenic movement disorder affecting many individuals treated with dopamine-receptor blocking agents (DRBAs). Studying treatment of TD can be complex, as the symptoms can be affected by changes in either dosage or type of DRBA, as well as by the variable natural course of the disease. Historically many pharmacological therapies have been studied in TD, finding varying degrees of treatment success. Most recently, the VMAT2 inhibitors valbenazine and deutetrabenazine were rigorously studied in TD in large, phase III clinical trials, and were shown to be beneficial in this population. In this article, we will review various treatments of TD, including manipulation of the offending agent, VMAT2 inhibitors, other non-VMAT2-inhibiting medications, and non-pharmacological approaches.

Antipsychotic reduction and/or cessation and antipsychotics as specific treatments for tardive dyskinesia

BACKGROUND

Since the 1950s antipsychotic medication has been extensively used to treat people with chronic mental illnesses such as schizophrenia. These drugs, however, have also been associated with a wide range of adverse effects, including movement disorders such as tardive dyskinesia (TD) - a problem often seen as repetitive involuntary movements around the mouth and face. Various strategies have been examined to reduce a person's cumulative exposure to antipsychotics. These strategies include dose reduction, intermittent dosing strategies such as drug holidays, and antipsychotic cessation.

OBJECTIVES

To determine whether a reduction or cessation of antipsychotic drugs is associated with a reduction in TD for people with schizophrenia (or other chronic mental illnesses) who have existing TD. Our secondary objective was to determine whether the use of specific antipsychotics for similar groups of people could be a treatment for TD that was already established.

SEARCH METHODS

We updated previous searches of Cochrane Schizophrenia's study-based Register of Trials including the registers of clinical trials (16 July 2015 and 26 April 2017). We searched references of all identified studies for further trial citations. We also contacted authors of trials for additional information.

SELECTION CRITERIA

We included reports if they assessed people with schizophrenia or other chronic mental illnesses who had established antipsychotic-induced TD, and had been randomly allocated to (a) antipsychotic maintenance versus antipsychotic cessation (placebo or no intervention), (b) antipsychotic maintenance versus antipsychotic reduction (including intermittent strategies), (c) specific antipsychotics for the treatment of TD versus placebo or no intervention, and (d) specific antipsychotics versus other antipsychotics or versus any other drugs for the treatment of TD.

DATA COLLECTION AND ANALYSIS

We independently extracted data from these trials and estimated risk ratios (RR) or mean differences (MD), with 95% confidence intervals (CI). We assumed that people who dropped out had no improvement.

MAIN RESULTS

We included 13 RCTs with 711 participants; eight of these studies were newly included in this 2017 update. One trial is ongoing.There was low-quality evidence of a clear difference on no clinically important improvement in TD favouring switch to risperidone compared with antipsychotic cessation (with placebo) (1 RCT, 42 people, RR 0.45 CI 0.23 to 0.89, low-quality evidence). Because evidence was of very low quality for antipsychotic dose reduction versus antipsychotic maintenance (2 RCTs, 17 people, RR 0.42 95% CI 0.17 to 1.04, very low-quality evidence), and for switch to a new antipsychotic versus switch to another new antipsychotic (5 comparisons, 5 RCTs, 140 people, no meta-analysis, effects for all comparisons equivocal), we are uncertain about these effects. There was low-quality evidence of a significant difference on extrapyramidal symptoms: use of antiparkinsonism medication favouring switch to quetiapine compared with switch to haloperidol (1 RCT, 45 people, RR 0.45 CI 0.21 to 0.96, low-quality evidence). There was no evidence of a difference for switch to risperidone or haloperidol compared with antipsychotic cessation (with placebo) (RR 1 RCT, 48 people, RR 2.08 95% CI 0.74 to 5.86, low-quality evidence) and switch to risperidone compared with switch to haloperidol (RR 1 RCT, 37 people, RR 0.68 95% CI 0.34 to 1.35, very low-quality evidence).Trials also reported on secondary outcomes such as other TD symptom outcomes, other adverse events outcomes, mental state, and leaving the study early, but the quality of the evidence for all these outcomes was very low due mainly to small sample sizes, very wide 95% CIs, and risk of bias. No trials reported on social confidence, social inclusion, social networks, or personalised quality of life, outcomes that we designated as being important to patients.

AUTHORS' CONCLUSIONS

Limited data from small studies using antipsychotic reduction or specific antipsychotic drugs as treatments for TD did not provide any convincing evidence of the value of these approaches. There is a need for larger trials of a longer duration to fully investigate this area.

Clozapine Treatment of Olanzapine-induced Tardive Dyskinesia: A Case Report

Tardive dyskinesias (TD) are serious, often irreversible side effects of dopamine blocking agents, most commonly first-generation antipsychotics. No definitive treatment exists, with different interventions showing inconsistent results. We report a case of TD presenting after 12 years of olanzapine therapy in a 66-year-old Hispanic male with paranoid schizophrenia. The TD symptoms were successfully treated within a few weeks by switching to clozapine. Two cases of olanzapine-induced TD treated with clozapine have previously been reported, but in those cases, the symptom onset was quicker, ranging from a few months to a few years after initiation of olanzapine therapy, and the treatment response was relatively slower. Clinicians should carefully monitor for symptoms of TD after prolonged treatment with olanzapine and other antipsychotics. If otherwise indicated for psychiatric treatment, clozapine can be considered a good choice for patients with TD in preventing or reversing the debilitating consequences of this condition.

Drug-induced movement disorders

INTRODUCTION

Drug-induced movement disorders (DIMDs) can be elicited by several kinds of pharmaceutical agents. The major groups of offending drugs include antidepressants, antipsychotics, antiepileptics, antimicrobials, antiarrhythmics, mood stabilisers and gastrointestinal drugs among others.

AREAS COVERED

This paper reviews literature covering each movement disorder induced by commercially available pharmaceuticals. Considering the magnitude of the topic, only the most prominent examples of offending agents were reported in each paragraph paying a special attention to the brief description of the pathomechanism and therapeutic options if available.

EXPERT OPINION

As the treatment of some DIMDs is quite challenging, a preventive approach is preferable. Accordingly, the use of the offending agents should be strictly limited to appropriate indications and they should be applied in as low doses and as short duration as the patient's condition allows. As most of DIMDs are related to an unspecific adverse action of medications in the basal ganglia and the cerebellum, future research should focus on better characterisation of the neurochemical profile of the affected functional systems, in addition to the development of drugs with higher selectivity and better side-effect profile.

Clozapine for treatment-resistant bipolar disorder: a systematic review

OBJECTIVE

To evaluate the efficacy and safety of clozapine for treatment-resistant bipolar disorder (TRBD).

METHODS

A systematic review of randomized controlled studies, open-label prospective studies, and retrospective studies of patients with TRBD was carried out. Interventions included clozapine monotherapy or clozapine combined with other medications. Outcome measures were efficacy and adverse drug reactions (ADRs).

RESULTS

Fifteen clinical trials with a total sample of 1,044 patients met the inclusion criteria. Clozapine monotherapy or clozapine combined with other treatments for TRBD was associated with improvement in: (i) symptoms of mania, depression, rapid cycling, and psychotic symptoms, with many patients with TRBD achieving a remission or response; (ii) the number and duration of hospitalizations, the number of psychotropic co-medications, and the number of hospital visits for somatic reasons for intentional self-harm/overdose; (iii) suicidal ideation and aggressive behavior; and (iv) social functioning. In addition, patients with TRBD showed greater clinical improvement in long-term follow-up when compared with published schizophrenia data. Sedation (12%), constipation (5.0%), sialorrhea (5.2%), weight gain (4%), and body ache/pain (2%) were the commonly reported ADRs; however, these symptoms but did not usually require drug discontinuation. The percentage of severe ADRs reported, such as leukopenia (2%), agranulocytosis (0.3%), and seizure (0.5%), appeared to be lower than those reported in the published schizophrenia literature.

CONCLUSION

The limited current evidence supports the concept that clozapine may be both an effective and a relatively safe medication for TRBD.

Clozapine and tardive movement disorders: a review

BACKGROUND

Tardive syndromes (TS) arise from long term exposure to dopamine receptor blocking agents. Clozapine has been considered to have low risk of causing new onset TS and is considered as a treatment option in patients with TS.

AIM

This review evaluates the usefulness of clozapine in patients with TS and occasional reports of clozapine causing TS.

METHODOLOGY

Electronic searches were carried out using the search engines of PUBMED, Science direct and Google Scholar databases. All reports describing use of clozapine in management of TS, monitoring of TS while on clozapine and onset of TS after initiation of clozapine were identified.

RESULTS

Fifteen trials and 28 case series/case reports describe the use of clozapine in TS. Most of these reports show that clozapine is useful in patients with TS, in the dose range of 200-300 mg/day and the beneficial effect is seen within 4-12 weeks of initiation. One case series and two case reports described clozapine withdrawal emergent dyskinesias suggesting a masking role of clozapine. One trial, three case series and two case reports describe beneficial effects of clozapine on long standing neurological syndromes. There is relatively less literature (2 trials and 15 case series/reports) describing the emergence of TS with clozapine.

CONCLUSION

Evidence of beneficial effects of clozapine in TS is greater than its role in causation/worsening of TS. Hence, clozapine should be considered in symptomatic patients who develop TS while receiving other antipsychotics. Further research on mechanism of TS and clozapine effect on TS is required.

Treatment of neurolept-induced tardive dyskinesia

Tardive dyskinesia (TDK) includes orobuccolingual movements and "piano-playing" movements of the limbs. It is a movement disorder of delayed onset that can occur in the setting of neuroleptic treatment as well as in other diseases and following treatment with other drugs. The specific pathophysiology resulting in TDK is still not completely understood but possible mechanisms include postsynaptic dopamine receptor hypersensitivity, abnormalities of striatal gamma-aminobutyric acid (GABA) neurons, and degeneration of striatal cholinergic interneurons. More recently, the theory of synaptic plasticity has been proposed. Considering these proposed mechanisms of disease, therapeutic interventions have attempted to manipulate dopamine, GABA, acetylcholine, norepinephrine and serotonin pathways and receptors. The data for the effectiveness of each class of drugs and the side effects were considered in turn.

Clozapine: balancing safety with superior antipsychotic efficacy

Clozapine is often referred to as the gold standard for the treatment of schizophrenia and yet has also been described as the most underutilized treatment for schizophrenia supported by solid evidence-based medicine. In 2008, it was used to treat only 4.4% of patients with schizophrenia in the U.S., which is ~10-20% of those with approved indications for clozapine for which there is no alternative of equal efficacy. Its use is much higher in Scandinavian countries and China. The primary indications for clozapine are: 1) treatment-resistant schizophrenia or schizoaffective disorder, defined as persistent moderate to severe delusions or hallucinations despite two or more clinical trials with other antipsychotic drugs; and, 2) patients with schizophrenia or schizoaffective disorder who are at high risk for suicide. Concerns over a number of safety considerations are responsible for much of the underutilization of clozapine: 1) agranulocytosis; 2) metabolic side effects; and, 3) myocarditis. These side effects can be detected, prevented, minimized and treated, but there will be a very small number of fatalities. Nevertheless, clozapine has been found in two large epidemiologic studies to have the lowest mortality of any antipsychotic drug, mainly due to its very large effect to reduce the risk for suicide. Other reasons for limited use of clozapine include the extra effort entailed in monitoring white blood cell counts to detect granulocytopenia or agranulocytosis and, possibly, minimal efforts to market it now that it is largely generic. Awareness of the benefits and risks of clozapine is essential for increasing the use of this lifesaving agent.

Effects of acute and long-term treatment with neuroleptics on regional telencephalic neurotensin levels in the male rat

By means of radioimmunoassay measurements of regional neurotensin (NT) levels in the forebrain of the male rat it was shown that selective D2 DA receptor antagonists, such as haloperidol and sulpiride, and unselective D1 and D2 antagonists such as thioridazine, flupenthixol clozapine and fluperlapine, can acutely increase NT levels in the striatum and the nucleus accumbens without affecting NT levels in the amygdaloid or anteromedial frontal cortex. Conversely, acute treatment with the D1 DA receptor antagonist Schering 23390 (SCH 23390) produced a selective reduction of striatal NT levels. After long-term treatment clozapine, fluperlapine or SCH 23390, tolerance developed with regard to their ability to modulate striatal and accumbens levels. No tolerance occurred after chronic haloperidol, chlorpromazine and sulpiride. The results indicate that the acute administration of D1 and D2 DA receptor antagonists differentially modifies NT levels in the striatum and nuc. accumbens, and that antipsychotic drugs showing a relative lack of extrapyramidal side effects may be characterised by a failure to maintain increased NT levels in the basal ganglia upon long-term treatment.

Treatment outcomes of patients with tardive dyskinesia and chronic schizophrenia

OBJECTIVE

We compared the response to antipsychotic treatment between patients with and without tardive dyskinesia (TD) and examined the course of TD.

METHOD

This analysis compared 200 patients with DSM-IV-defined schizophrenia and TD and 997 patients without TD, all of whom were randomly assigned to receive one of 4 second-generation antipsychotics. The primary clinical outcome measure was time to all-cause treatment discontinuation, and the primary measure for evaluating the course of TD was change from baseline in Abnormal Involuntary Movement Scale (AIMS) score. Kaplan-Meier survival analysis and Cox proportional hazards regression models were used to compare treatment discontinuation between groups. Changes in Positive and Negative Syndrome Scale (PANSS) and neurocognitive scores were compared using mixed models and analysis of variance. Treatment differences between drugs in AIMS scores and all-cause discontinuation were examined for those with TD at baseline. Percentages of patients meeting criteria for TD postbaseline or showing changes in AIMS scores were evaluated with χ(2) tests. Data were collected from January 2001 to December 2004.

RESULTS

Time to treatment discontinuation for any cause was not significantly different between the TD and non-TD groups (χ(2)(1) = 0.11, P = .743). Changes in PANSS scores were not significantly different (F(1,974) = 0.82, P = .366), but patients with TD showed less improvement in neurocognitive scores (F(1,359) = 6.53, P = .011). Among patients with TD, there were no significant differences between drugs in the decline in AIMS scores (F(3,151) = 0.32, P = .811); 55% met criteria for TD at 2 consecutive visits postbaseline, 76% met criteria for TD at some or all postbaseline visits, 24% did not meet criteria for TD at any subsequent visit, 32% showed a ≥ 50% decrease in AIMS score, and 7% showed a ≥ 50% increase in AIMS score.

CONCLUSIONS

Schizophrenia patients with and without TD were similar in time to discontinuation of treatment for any cause and improvement in psychopathology, but differed in neurocognitive response. There were no significant differences between treatments in the course of TD, with most patients showing either persistence of or fluctuation in observable symptoms.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00014001.

Clozapine-induced tardive dyskinesia in schizophrenic patients taking clozapine as a first-line antipsychotic drug

OBJECTIVE

Clozapine causes few extrapyramidal symptoms and is recommended as a treatment drug for severe tardive dyskinesia (TD). However, several case reports have suggested that clozapine could also cause TD. We investigated whether clozapine used as a first-line antipsychotic drug can cause TD.

METHOD

We identified 101 patients at Yanbian Socio-Mental Hospital and Yanbian Brain Hospital in China who had received clozapine as a primary antipsychotic drug since their first episode of illness and evaluated the prevalence rate, type, and severity of TD using the Extrapyramidal Symptoms Rating Scale (ESRS). The criterion for TD was a score of > or = 3 on one item or 2 on two or more items of the ESRS.

RESULTS

The mean age and duration of illness of the patients were 38.93+/-8.36 and 12.88+/-6.90 years, respectively. The mean duration of clozapine treatment was 12.10+/-6.26 years. The prevalence of TD was 3.96% (4/101). Compared to patients without TD, patients with TD had a long duration of illness and clozapine treatment; all had the orolingual type of TD. TD was relatively mild, with a mean score of 4.75, and tended to accentuate with an activation procedure of rapid pronation and supination of the hands.

CONCLUSIONS

These results suggest that clozapine may cause TD; however, the prevalence is low and the severity is relatively mild, with no or mild self-reported discomfort. Therefore, we recommend that regular examination for TD using the activation procedure should be performed in patients who use clozapine on a long-term basis.

Clozapine versus typical neuroleptic medication for schizophrenia

BACKGROUND

Long-term drug treatment of schizophrenia with typical antipsychotics has limitations: 25 to 33% of patients have illnesses that are treatment-resistant. Clozapine is an antipsychotic drug, which is claimed to have superior efficacy and to cause fewer motor adverse effects than typical drugs for people with treatment-resistant illnesses. Clozapine carries a significant risk of serious blood disorders, which necessitates mandatory weekly blood monitoring at least during the first months of treatment.

OBJECTIVES

To evaluate the effects of clozapine compared with typical antipsychotic drugs in people with schizophrenia.

SEARCH STRATEGY

For the current update of this review (March 2006) we searched the Cochrane Schizophrenia Group Trials Register.

SELECTION CRITERIA

All relevant randomised clinical trials (RCTs).

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis, based on a fixed-effect model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (WMD) again based on a fixed-effect model.

MAIN RESULTS

We have included 42 trials (3950 participants) in this review. Twenty-eight of the included studies are less than 13 weeks in duration, and, overall, trials were at significant risk of bias. We found no significant difference in the effects of clozapine and typical neuroleptic drugs for broad outcomes such as mortality, ability to work or suitability for discharge at the end of the study. Clinical improvements were seen more frequently in those taking clozapine (n=1119, 14 RCTs, RR 0.72 CI 0.7 to 0.8, NNT 6 CI 5 to 8). Also, participants given clozapine had fewer relapses than those on typical antipsychotic drugs (n=1303, RR 0.62 CI 0.5 to 0.8, NNT 21 CI 15 to 49). BPRS scores showed a greater reduction of symptoms in clozapine-treated patients, (n=1145, 16 RCTs, WMD -4.22 CI -5.4 to -3.1), although the data were heterogeneous (Chi(2) 0.0001, I(2) 66%). Short-term data from the SANS negative symptom scores favoured clozapine (n=196, 5 RCTs, WMD -5.92 CI -7.8 to -4.1). We found clozapine to be more acceptable in long-term treatment than conventional antipsychotic drugs (n=982, 16 RCTs, RR 0.60 CI 0.5 to 0.7, NNT 15 CI 12 to 20). Blood problems occurred more frequently in participants receiving clozapine (3.2%) compared with those given typical antipsychotics (0%) (n=1031, 13 RCTs, RR 7.09 CI 2.0 to 25.6). Clozapine participants experienced more drowsiness, hypersalivation, or temperature increase, than those given conventional neuroleptics. However, clozapine patients experienced fewer motor adverse effects (n=1433, 18 RCTs, RR 0.58 CI 0.5 to 0.7, NNT 5 CI 4 to 6).The clinical effects of clozapine were more pronounced in participants resistant to typical neuroleptics in terms of clinical improvement (n=370, 4 RCTs, RR 0.71 CI 0.6 to 0.8, NNT 4 CI 3 to 6) and symptom reduction. Thirty-four per cent of treatment-resistant participants had a clinical improvement with clozapine treatment.

AUTHORS' CONCLUSIONS

Clozapine may be more effective in reducing symptoms of schizophrenia, producing clinically meaningful improvements and postponing relapse, than typical antipsychotic drugs - but data are weak and prone to bias. Participants were more satisfied with clozapine treatment than with typical neuroleptic treatment. The clinical effect of clozapine, however, is, at least in the short term, not reflected in measures of global functioning such as ability to leave the hospital and maintain an occupation. The short-term benefits of clozapine have to be weighed against the risk of adverse effects. Within the context of trials, the potentially dangerous white blood cell decline seems to be more frequent in children and adolescents and in the elderly than in young adults or people of middle-age.The existing trials have largely neglected to assess the views of participants and their families on clozapine. More community-based long-term randomised trials are needed to evaluate the efficacy of clozapine on global and social functioning as trials in special groups such as people with learning disabilities.

Neuroleptic reduction and/or cessation and neuroleptics as specific treatments for tardive dyskinesia

BACKGROUND

Since the 1950s neuroleptic medication has been extensively used to treat people with chronic mental illnesses such as schizophrenia. These drugs, however, have been also associated with a wide range of adverse effects, including movement disorders such as tardive dyskinesia (TD). Various strategies have been examined to reduce a person's cumulative exposure to neuroleptics. These studies include dose reduction, intermittent dosing strategies such as drug holidays, and neuroleptic cessation.

OBJECTIVES

To determine whether a reduction or cessation of neuroleptic drugs is associated with a reduction in TD, for people with schizophrenia (or other chronic mental illnesses) who have existing TD. Our secondary objective was to determine whether the use of specific neuroleptics for similar groups of people could be a treatment for TD that was already established.

SEARCH STRATEGY

We updated previous searches of the Cochrane Schizophrenia Groups Register (1997), Biological Abstracts (1982-1997), EMBASE (1980-1997), LILACS (1982-1996), MEDLINE (1966-1997), PsycLIT (1974-1997), and SCISEARCH (1997) by searching the Cochrane Schizophrenia Groups Register (July 2003). We searched references of all identified studies for further trial citations. We also contacted the principal authors of trials for further unpublished trials.

SELECTION CRITERIA

We included reports if they assessed people with schizophrenia or other chronic mental illnesses who had established neuroleptic-induced TD, and had been randomly allocated to (a) neuroleptic maintenance versus neuroleptic cessation (placebo or no intervention), (b) neuroleptic maintenance versus neuroleptic reduction (including intermittent strategies), and (c) specific neuroleptics for the treatment of TD versus, placebo or intervention. A post hoc decision was made to broaden comparison (c) to include specific neuroleptics versus other neuroleptics for the treatment of TD.

DATA COLLECTION AND ANALYSIS

We (KSW, JR) independently inspected citations and, where possible, abstracts, ordered papers, and re-inspected and quality assessed these and extracted data. We analysed dichotomous data using random effects relative risk (RR) and estimated the 95% confidence interval (CI). Where possible we calculated the number needed to treat (NNT) or number needed to harm statistic (NNH). We excluded continuous data if more than 50% of people were lost to follow up, but, where possible, we calculated the weighted mean difference (WMD). It was assumed that those leaving the study early showed no improvement.

MAIN RESULTS

We included five trials and excluded 102. One small two week study (n=18), reported on the 'masking' effects of molindone and haloperidol on TD, which favoured haloperidol (RR 3.44 CI 1.1 to 5.8). Two (total n=17) studies found no reduction in TD associated with neuroleptic reduction (RR 0.38 CI 0.1 to 1.0). One study (n=20) found no significant differences in oral dyskinesia (RR 2.45 CI 0.3 to 19.7) when neuroleptics were compared as a specific treatment for TD. Dyskinesia was found to be not significantly different (n=32, RR 0.62 CI 0.3 to 1.26) between quetiapine and haloperidol when these neuroleptics were used as specific treatments for TD, although the need for additional neuroleptics was significantly lower in the quetiapine group (n=47, RR 0.49 CI 0.2 to 1.0) than in those given haloperidol.

AUTHORS' CONCLUSIONS

Limited data from small studies using neuroleptic reduction or specific neuroleptic drugs as treatments for TD did not provide any convincing evidence of the value of these approaches. There is a need for larger trials of a longer duration in order to fully investigate this area.

Extrapyramidal symptoms with atypical antipsychotics : incidence, prevention and management

The treatment of schizophrenia changed drastically with the discovery of antipsychotic medications in the 1950s, the release of clozapine in the US in 1989 and the subsequent development of the atypical or novel antipsychotics. These newer medications differ from their conventional counterparts, primarily based on their reduced risk of extrapyramidal symptoms (EPS). EPS can be categorised as acute (dystonia, akathisia and parkinsonism) and tardive (tardive dyskinesia and tardive dystonia) syndromes. They are thought to have a significant impact on subjective tolerability and adherence with antipsychotic therapy in addition to impacting function. Unlike conventional antipsychotic medications, atypical antipsychotics have a significantly diminished risk of inducing acute EPS at recommended dose ranges. These drugs may also have a reduced risk of causing tardive dyskinesia and in some cases may have the ability to suppress pre-existing tardive dyskinesia. This paper reviews the available evidence regarding the incidence of acute EPS and tardive syndromes with atypical antipsychotic therapy. Estimates of incidence are subject to several confounds, including differing methods for detection and diagnosis of EPS, pretreatment effects and issues surrounding the administration of antipsychotic medications. The treatment of acute EPS and tardive dyskinesia now includes atypical antipsychotic therapy itself, although other adjunctive strategies such as antioxidants have also shown promise in preliminary trials. The use of atypical antipsychotics as first line therapy for the treatment of schizophrenia is based largely on their reduced risk of EPS compared with conventional antipsychotics. Nevertheless, EPS with these drugs can occur, particularly when prescribed at high doses. The EPS advantages offered by the atypical antipsychotics must be balanced against other important adverse effects, such as weight gain and diabetes mellitus, now known to be associated with these drugs.

Tardive dyskinesia in the era of typical and atypical antipsychotics. Part 2: Incidence and management strategies in patients with schizophrenia

OBJECTIVE

Tardive dyskinesia (TD), the principal adverse effect of long-term conventional antipsychotic treatment, can be debilitating and, in many cases, persistent. We sought to explore the incidence and management of TD in the era of atypical antipsychotics because it remains an important iatrogenic adverse effect.

METHODS

We conducted a review of TD incidence and management literature from January 1, 1965, to January 31, 2004, using the terms tardive dyskinesia, management, therapy, neuroleptics, antipsychotics, clozapine, olanzapine, risperidone, quetiapine, ziprasidone, and aripiprazole. Additional articles were obtained by searching the bibliographies of relevant references. We considered articles that contributed to the current understanding of both the incidence of TD with atypical antipsychotics and management strategies for TD.

RESULTS

The incidence of TD is significantly lower with atypical, compared with typical, antipsychotics, but cases of de novo TD have been identified. Evidence suggests that atypical antipsychotic therapy ameliorates long-standing TD. This paper outlines management strategies for TD in patients with schizophrenia.

CONCLUSION

The literature supports the recommendation that atypical antipsychotics should be the first antipsychotics used in patients who have experienced TD as a result of treatment with conventional antipsychotic agents. The other management strategies discussed may prove useful in certain patients.

Olanzapine treatment for tardive dyskinesia in schizophrenia patients: a prospective clinical trial with patients randomized to blinded dose reduction periods

BACKGROUND

Tardive dyskinesia (TD) is a potentially persistent and disabling abnormal involuntary movement disorder. The aim of this 8-month study was to determine if olanzapine treatment could lead to a significant and persistent reduction in preexisting TD.

METHODS

Eligible schizophrenia patients met restricted Research Diagnosis criteria of TD requiring, in part, a rating of at least moderate severity (score > or = 3) in one or more of seven body regions on the Abnormal Involuntary Movement Scale (AIMS). Patients received olanzapine, 5-20 mg/day, for 8 months. During this period, they underwent one to two dose reduction periods under blinded conditions. Concurrent changes in TD, psychopathology, parkinsonism and akathisia were assessed with the AIMS, the Positive and Negative Syndrome Scale (PANSS), and the Simpson-Angus and Barnes Akathisia Scales, respectively.

RESULTS

A significant reduction in mean AIMS total score was demonstrated at endpoint (n = 92; p < 0.001) as well as at each visit (p < 0.001) and as early as Week 1 on olanzapine. Approximately 70% of patients no longer met the restricted Research Diagnostic criteria for persistent TD (RD-TD) after 8 months of treatment. No statistically significant rebound worsening of TD was found during either blinded drug reduction period. Significant improvement in psychopathology (p = 0.001) and parkinsonism (p < 0.001) was observed.

CONCLUSIONS

Improvement in the severity of preexisting TD was achieved with olanzapine and persisted throughout the 8-month study and during each dose reduction period. Overall improvement in clinical status suggests that olanzapine may be effective for the long-term management of schizophrenia patients with preexisting TD.

Classification and treatment of tardive syndromes

BACKGROUND

Tardive syndromes are a group of delayed-onset abnormal involuntary movement disorders induced by a dopamine receptor blocking agent. There are several phenomenologically distinct types of TS.

REVIEW SUMMARY

The term tardive dyskinesia has been used to refer to the TS that presents with rapid, repetitive, stereotypic movements mostly involving the oral, buccal, and lingual areas. Tardive dystonia can be focal, segmental, or generalized. It commonly affects the face and neck followed by the arms and trunk. It usually results in retrocollis when it involves the neck and trunk arching backwards when it involves the trunk. Tardive akathisia is characterized by a feeling of inner restlessness and jitteriness with an inability to sit or stand still. Other tardive syndromes include tardive tics, myoclonus, tremor, and withdrawal-emergent syndrome. It remains unclear whether tardive parkinsonism truly exists. The only way to prevent TS is to avoid its etiologic agents. Chronic use of dopamine receptor blocking agents should be limited as much as possible to patients with chronic psychoses. In general, for mild TS, reducing the neuroleptic dose, switching to an atypical agent, or discontinuing antipsychotic treatment altogether in the hope of facilitating remission is recommended. For moderate to severe TS, tetrabenazine or reserpine may be the most effective agent. Neuroleptics should be resumed to treat TD in the absence of active psychosis only as a last resort for persistent, disabling, and treatment-resistant TD.

CONCLUSIONS

The severity of the TS and the absolute need for antipsychotic therapy often dictate the treatment approach for this disorder.

Tardive dyskinesias and antipsychotics: a review

Currently, tardive dyskinesia (TD) remains an important clinical problem. The average prevalence is estimated at 30%. The appearance of antipsychotics has opened new paths. The extrapyramidal profile of these molecules is more favorable than that of conventional neuroleptics. In order to assess their prophylactic as well as curative potential, we reviewed the literature concerning four of these atypical antipsychotics: clozapine, risperidone olanzapine and amisulpride. Clozapine seems to induce fewer cases of TD than the conventional neuroleptics, and has a specific therapeutic effect. However, the risk of agranulocytosis reduces the possibility of utilisation. Risperidone appears to be an effective therapy, but several authors report cases of TD during treatment. Furthermore, larger studies and longer follow-ups are necessary to confirm the efficiency of olanzapine and amisulpride. Further studies and observations are still necessary before drawing any conclusion for these new atypical antipsychotic actions. They are doubtlessly promising, but we cannot ignore the notion of risk-benefit; regular monitoring and listening to the subjective experience of the patients must remain uppermost in the choice of therapy.

Effects of newer antipsychotics on extrapyramidal function

Following acceptance of clozapine as a superior antipsychotic agent with low risk of adverse extrapyramidal syndromes (EPS), such as dystonia, parkinsonism, akathisia or tardive dyskinesia, several novel antipsychotic drugs have been developed with properties modelled on those of clozapine. Though generally considered 'atypical' in their relatively low risk of inducing EPS, these agents vary considerably in their pharmacology and impact on neurological functioning. Although few comparative data are available, the atypical antipsychotics can be tentatively ranked by EPS risk (excluding akathisia and neuroleptic malignant syndrome) in the following order: clozapine < quetiapine < olanzapine = ziprasidone. At higher doses, risperidone is ranked with a higher EPS risk than olanzapine and ziprasidone, but its risk of EPS is lower with lower doses. In general, this ranking is inversely related to antidopaminergic (D2 receptor) potency. The high antiserotonergic (5-HT2A receptor) potency of risperidone, clozapine, ziprasidone and olanzapine, but not quetiapine, as well as the antimuscarinic activity of olanzapine and clozapine may also limit EPS. For the treatment of psychotic reactions to dopamine agonist therapy in Parkinson's disease, clozapine is both effective and relatively well tolerated; quetiapine may be tolerated, olanzapine is not well tolerated, risperidone is poorly tolerated, and amisulpride and ziprasidone have not been well evaluated. Clozapine, perhaps because of its anticholinergic activity, can reduce parkinsonian tremor. It is useful for ongoing psychosis with tardive dyskinesia, especially for dystonic features. No atypical antipsychotic is clearly effective for motor abnormalities in Huntington's disease or Tourette's syndrome, and the effect of these drugs on other neurological disorders have been well evaluated in only small numbers of patients. In summary, with the exception of clozapine, and perhaps quetiapine, atypical antipsychotics have brought only relative avoidance of EPS, strongly encouraging continued searches for novel antipsychotic agents.

Clinical research on antipsychotics in bipolar disorder

Antipsychotics are commonly used in bipolar disorder, both for acute mania and in maintenance treatment. The authors review available clinical research concerning the use of both conventional and atypical antipsychotics in bipolar disorder and present recommendations for a number of key clinical situations based on this review. They also consider a number of important related questions, including whether there is evidence for an increased risk of tardive dyskinesia (TD) in patients with bipolar disorder, the potential role for antipsychotics in the treatment of bipolar depression, the role of antipsychotics in maintenance treatment of bipolar disorder, the potential for antipsychotics to induce depression in bipolar illness, and whether antipsychotics can be considered mood stabilizers with a place as monotherapy for bipolar mania. They conclude that standard treatment for acute mania should begin with a mood stabilizer, with benzodiazepines used as an adjunct for mild agitation or insomnia and antipsychotics used as an adjunct for highly agitated, psychotic, or severely manic patients. They also conclude that atypical antipsychotics are preferable to conventional antispychotics because of their more favorable side effect profile and reduced risk of tardive dyskinesia. They review the evidence for using atypical antipsychotics as first-line monotherapy for mania and conclude that more evidence concerning the risk of TD and their efficacy as maintenance treatment in bipolar disorder is needed before a conclusion can be made. Should the eventual risk of TD associated with atypical antipsychotics be found to be minimal and their efficacy in maintenance treatment found to be high, they could eventually be considered first line monotherapy for bipolar disorder. They conclude that treatment with an antipsychotic during bipolar depression should be limited to those patients who have psychosis and that atypical antipsychotics are preferred over conventional antipsychotics in this situation, not only because of their reduced risk of side effects but also because theoretically they may have antidepressant efficacy due to their effects on the serotonin system. The clinical research findings summarized in the article are, for the most part, supported by a recently published guideline based on a consensus of clinical experts.

Clozapine versus typical neuroleptic medication for schizophrenia

BACKGROUND

Long-term drug treatment of schizophrenia with conventional antipsychotics has limitations: 25-33% of patients have illnesses that are treatment-resistant. Clozapine is an atypical antipsychotic drug, which is claimed to have superior efficacy and to cause fewer motor adverse effects than typical drugs for people with treatment-resistant illnesses. Clozapine carries a significant risk of serious blood disorders, which necessitates mandatory weekly blood monitoring at least during the first months of treatment.

OBJECTIVES

To evaluate the effects of clozapine for schizophrenia in comparison to typical antipsychotic drugs.

SEARCH STRATEGY

Publications in all languages were searched from the following databases: Biological Abstracts (1982-1999), The Cochrane Library CENTRAL (Issue 2, 1999), Cochrane Schizophrenia Group's Specialised Register (1999), EMbase (1980-1999), ISI Citation Index, LILACS (1982-1999), MEDLINE (1966-1999), and PsycLIT (1974-1999). Reference list screening of included papers was performed. Authors of recent trials and the manufacturer of clozapine contacted.

SELECTION CRITERIA

All randomised controlled trials comparing clozapine with typical antipsychotic drugs were included by independent assessment by at least two reviewers.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by at least two reviewers. Authors of trials published since 1980 were contacted for additional and missing data. Odds ratios (OR) and 95% confidence intervals (CI) of homogeneous dichotomous data were calculated with the Peto method. A random effects model was used for heterogeneous dichotomous data. Where possible the numbers needed to treat (NNT) or needed to harm (NNH) were also calculated. Weighted or standardised means were calculated for continuous data.

MAIN RESULTS

Currently the review includes 31 studies, 26 of which are less than 13 weeks in duration. These studies include 2589 participants, most of whom were men (74%). The average age was 38 years. There was no difference in the effects of clozapine and typical neuroleptic drugs for broad outcomes such as mortality, ability to work or suitability for discharge at end of the study. Clinical improvement was seen more frequently in those taking clozapine (random effects OR 0.4 CI 0.2-0.6, NNT 6) both in the short and the long term. Also, in the short term, participants on clozapine had fewer relapses than those on typical antipsychotic drugs (OR 0.6 CI 0.4-0.8, NNT 20 CI 17-38), and this may be true for long-term treatment as well. Symptom assessment scales showed a greater reduction of symptoms in clozapine-treated patients. Clozapine treatment was more acceptable than low-potency antipsychotics such as chlorpromazine (OR 0.6 CI 0.4-0.9) but did not differ from acceptability of high-potency neuroleptics such as haloperidol (random effects OR 0.8 CI 0.4-1.5). Clozapine was more acceptable in long-term treatment than conventional antipsychotic drugs (random effects OR 0.4 CI 0.2-0.7, NNT 6 CI 3-111). Patients were more satisfied with clozapine treatment (OR 0.5 CI 0.3-0.8, NNT 12 CI 7-37), but they experienced more hypersalivation, temperature increase, and drowsiness than those given conventional neuroleptics. However, clozapine patients experience fewer motor side effects and less dry mouth. The clinical efficacy of clozapine was more pronounced in participants resistant to typical neuroleptics in terms of clinical improvement (random effects OR 0.2 CI 0.1-0.5, NNT 5 CI 4-7) and symptom reduction. Thirty-two percent of treatment resistant people had a clinical improvement with clozapine treatment.

REVIEWER'S CONCLUSIONS

This systematic review confirms that clozapine is convincingly more effective than typical antipsychotic drugs in reducing symptoms of schizophrenia, producing clinically meaningful improvements and postponing relapse. Patients were more satisfied with clozapine treatment than with typical neuroleptic treatment. (ABSTRACT TRUNCATED

Neuroleptic reduction and/or cessation and neuroleptics as specific treatments for tardive dyskinesia

BACKGROUND

Since the 1950s neuroleptic medication has been extensively used to treat people with chronic mental illnesses, such as schizophrenia. These drugs, however, have been also associated with a wide range of adverse effects, including movement disorders such as tardive dyskinesia (TD). Various strategies have been examined to reduce a person's cumulative exposure to neuroleptics. These studies include dose reduction, intermittent dosing strategies, such as drug holidays, and neuroleptic cessation.

OBJECTIVES

To determine whether, for those people with both schizophrenia (or other chronic mental illnesses) and tardive dyskinesia (TD), a reduction or cessation of neuroleptic drugs was associated with reduction in TD symptoms. A secondary objective was to determine whether the use of specific neuroleptics for similar groups of people could be a treatment for already established TD.

SEARCH STRATEGY

Electronic searches of Biological Abstracts (1982-1997), Cochrane Schizophrenia Group's Register of trials (1997), EMBASE (1980-1997), LILACS (1982-1996), MEDLINE (1966-1997), PsycLIT (1974-1997), and SCISEARCH (1997) were undertaken. References of all identified studies were searched for further trial citations. Principal authors of trials were contacted.

SELECTION CRITERIA

Reports were included if they assessed the treatment of neuroleptic-induced tardive dyskinesia in people with schizophrenia or other chronic mental illnesses and already established TD, who had been randomly allocated to (a) neuroleptic cessation (placebo or no intervention) versus neuroleptic maintenance; b. neuroleptic reduction (including intermittent strategies) versus neuroleptic maintenance; or c. specific neuroleptics for the treatment of TD versus placebo or no intervention.

DATA COLLECTION AND ANALYSIS

The reviewers extracted the data independently and the Odds Ratio (95% CI) or the average difference (95% CI) were estimated. The reviewers assumed that people who dropped out had no improvement.

MAIN RESULTS

Two trials were able to be included in this review. Sixty two were excluded and 16 are awaiting assessment. Seven trials are still pending classification. No randomised controlled trial-derived data were available to clarify the role of neuroleptics as treatments for TD. This includes the atypical antipsychotics including clozapine. Despite neuroleptic cessation being a frequently first-line recommendation, there were no RCT-derived data to support this. Two studies ( approximately approximately Cookson 1987 approximately approximately , approximately approximately Kane 1983 approximately approximately ) found a reduction in TD associated with neuroleptic reduction.

REVIEWER'S CONCLUSIONS

The lack of evidence to support the efficacy of neuroleptic cessation as a treatment for TD, combined with the accumulating evidence of an increased risk of relapse should antipsychotic drugs be reduced, makes this intervention a hazardous treatment for TD. Dose reduction may offer some benefit as a treatment for TD compared to standard levels of neuroleptic use. There is a need to evaluate the utility of clozapine and the 'atypical' antipsychotics as treatments for established TD.

New strategies for old problems: tardive dyskinesia (TD). Review and report on severe TD cases treated with clozapine, with 12, 8 and 5 years of video follow-up

Tardive dyskinesia (TD) is the most feared and troublesome extrapyramidal side-effect of prolonged neuroleptic (NL) treatment. We present a review of TD. Its pathophysiology remains elusive, although extrapyramidal symptoms (EPS) increase the liability for TD. Nowadays, therefore, avoidance of all EPS remains the best preventive strategy, as it is not possible to predict which liable patients will develop TD, or of what type or severity. TD frequently includes dystonic features, and is more disabling when these dystonias are present. Clozapine (CLZ) has been reported to be effective in suppressing nearly 60% of TD syndromes, specially those with dystonic features. Based on the few reports in the literature on CLZ and TD by the early 1980s, we started to videotape the first severe TD patient treated with CLZ in 1984. We present the first three case reports of severe TD, with prominent disabling dystonic features, treated with CLZ and videotaped since pretreatment and then periodically for 12, 8 and 5 years of follow-up, respectively. The patients' current diagnosis, gender and age are: Case 1, DSM-IV Schizophrenia Residual Type, male, 39 years; Case 2, DSM-IV Polysubstance Related Disorder, Borderline Personality Disorder, female, 28 years; Case 3, DSM-IV Schizoaffective Disorder, male, 40 years. Two of them presented with a recurrence of TD because of CLZ interruption within the first 2 months of treatment, with no further breakthrough to date. The first two cases have complete remission of TD; the third case is still improving after 5 years of CLZ treatment, with only minor dystonic features persisting that constitute no impairment for work or daily routines at present. All patients, independent of their psychiatric primary diagnosis, have shown significant and progressive improvement in both motor and psychosocial aspects. None of them has been rehospitalized. Long-term treatment and follow-up is required to avoid TD recurrence and to assure full assessment of treatment effectiveness. Ideally, periodic video recording with standardized examination is advisable for long-term follow-up and outcome assessment. At present, CLZ could be regarded as the drug of choice for patients with TD, specially for those with disabling and or dystonic features and who require ongoing NL therapy. The use of novel antipsychotic agents for TD treatment and prevention, with their low EPS liability, is promising, but has yet to be tested.

The emerging role of clozapine in the treatment of movement disorders

Clozapine, the only commercially available atypical neuroleptic, is approved for the treatment of schizophrenic patients who are unresponsive to or intolerant of typical neuroleptics. It has an unusual pharmacologic profile compared with standard neuroleptics, and it follows that clinical response to this drug is also different. It has shattered the notion that a drug must be capable of inducing or worsening parkinsonism to be a potent antipsychotic. Based on these findings, it is being used increasingly by neurologists for psychiatric and nonpsychiatric problems in patients with movement disorders. The most common use for clozapine among neurologists is in the management of drug-induced psychosis in Parkinson's disease (PD). This problem has been a source of increased morbidity and mortality in PD because of a lack of adequate therapeutic intervention. At this time, because of success in numerous open trials, with improvement of > 80% of patients, clozapine therapy for psychosis in PD is becoming the standard of care. It also appears to be of value in the management of some motor features of PD, including tremors and dyskinesia and possibly even sensory symptoms such as akathisia and pain. The literature also suggests that clozapine may be of potential benefit in hyperkinetic movement disorders including essential tremor, Huntington's disease, and tardive dyskinesia. We review the current data concerning the use of clozapine in patients with these movement disorders and others.

Changing antipsychotic medication: guidelines on the transition to treatment with risperidone. The Consensus Study Group on Risperidone Dosing

When treating patients with psychoses, clinicians must often consider changing their treatment from one antipsychotic agent to another. The transition may be necessary because the patient experiences serious side effects or because the existing therapy no longer controls the patient's symptoms. A principal problem in changing antipsychotic agents is the potential for withdrawal symptoms resulting from discontinuation of the existing therapy. These syndromes can manifest as reemergence or worsening of psychosis, rebound or unmasked dyskinesia, and cholinergic-rebound symptoms. Withdrawal signs and symptoms may include insomnia, nausea, vomiting, anxiety, and agitation. When switching a patient to the new antipsychotic agent risperidone, the clinician can keep withdrawal symptoms to a minimum by considering the patient's clinical history and current status. For some patients, abrupt withdrawal of the current antipsychotic may be possible. For others, the dose of the previous medication must be gradually reduced before risperidone is initiated. In many cases, the transition is best made by overlapping the existing therapy and risperidone.

Clozapine versus typical antipsychotics. A retro- and prospective study of extrapyramidal side effects

Schizophrenic patients in long-term neuroleptic monotherapy with clozapine (n = 100) and perphenazine, flupenthixol or zuclopentixol (controls, n = 100) were evaluated for extrapyramidal side effects (EPS) (blind) as well as other side effects and mental condition (non-blind). In both groups the patients had received neuroleptic treatment for a total of 14 years (median) and the present antipsychotic (clozapine or control drug) for 5 years. Thus the clozapine-treated patients had previously received traditional neuroleptics for 9 years (median). The study was both retrospective (0.3-19 years for clozapine, 0.3-24 years for control drug, by means of chart information) and prospective (1 year, with video-controlled evaluation of EPS). There was a significantly lower prevalence of tardive dyskinesia (TD) in clozapine treated patients than control patients, although prior to this treatment there were more TD patients in the clozapine group (P < 0.05). This lower level of TD in the clozapine group was related to a lower induction of new cases (P < 0.001) and a tendency towards greater disappearance of TD in the clozapine than in the control group (P = 0.07). Clozapine treated patients without TD had started clozapine and ceased traditional neuroleptics at an earlier age than those with TD. Parkinsonian signs were seen in 33% of the clozapine patients versus 61% of the control patients, mainly as hypokinesia; tremor in 3% versus 11% and rigidity in 0 versus 19%. Psychic akathisia was found in 14% versus 40% and motor akathisia in 7% versus 29% of the patients, all differences significantly in favor of clozapine. Clozapine treated patients also had less neuroleptic-induced emotional indifference and depression, but more autonomic side effects than controls.

High frequency oral movements induced by long-term administration of amperozide but not FG5803 in rats

Long-term studies of antipsychotic-induced oral movements may serve as a rat model of acute and tardive movement disorders. Vacuous chewing movements (VCM), tongue protrusions (TP), and jaw tremors (TR) were studied in rats during acute and chronic administration of two potential antipsychotics, amperozide and FG5803. Comparisons were made with haloperidol and vehicle. Single intraperitoneal injections of amperozide (0.2, 1, or 5 mg/kg) or FG5803 (1.2, 6, or 30 mg/kg) were without effect on oral behaviors. During long-term drug administration, withdrawal and readministration, endpoint analysis was focused on changes in supranormal oral movements. The maximal mean control frequencies found at 29 sessions during 14 months experiment +2 standard deviations were used to define the upper limit of the normal range. FG5803 (1.2, 6, or 30 mg/kg per day) administered via the drinking water for 12 months, did not produce significant deviations from this normal range with respect to VCM, TP, or TR, and this drug was not studied further. Rats receiving amperozide (0.2, 1, or 5 mg/kg per day) showed dose-related increases in oral movements over the year. The changes began after 3 months of treatment with amperozide 1 and 5 mg/kg per day, but became statistically significant only during the second half of the treatment year. Amperozide 0.2 mg/kg per day did not produce significant changes in oral movements during administration for a year, but drug withdrawal resulted in a significant rise in TP behavior. Haloperidol (1 mg/kg per day) produced increases in supranormal oral movements which tended to level out after 9 months. In all groups with significant elevations (i.e. haloperidol and amperozide 1 and 5 mg/kg per day), there was a persistence of such movements during a month of drug withdrawal. During treatment with amperozide (1 or 5 mg/kg per day), some rats developed a high frequency chewing behavior up to 175 VCMs/min. It is concluded that long-term treatment with amperozide, but not FG5803, produced a tardive pattern of supranormal oral movements. The importance of these findings for the clinical future of amperozide is difficult to predict, due to the unexpected finding of high-frequency chewing, which has not been noticed before during extensive studies of classical neuroleptics.

Clozapine withdrawal effects and receptor profiles of typical and atypical neuroleptics

Withdrawal effects of neuroleptics have not received much attention. Clozapine withdrawal phenomena have been attributed to psychosis arising from D2 supersensitivity, which is unlikely since it has minimal action on D2 receptors. The time course and clinical features of this phenomenon suggest that cholinergic overdrive and gamma-aminobutyric acid (GABA) supersensitivity occurs after withdrawal, since it is strongly anticholinergic and has a GABAergic action. Recently, a number of patients showed marked decompensation when they were switched from clozapine to risperidone, especially when they were rapidly tapered off clozapine. This was probably more due to withdrawal effects than the primary psychosis or a lack of efficacy of risperidone. A slow withdrawal schedule would facilitate homeostatic mechanisms; anticholinergics would be useful in clozapine withdrawal. This area has not received any attention from researchers, nor are there any guidelines for clinicians. This will be particularly important with the widespread use of atypical agents in the future.

Rebound insomnia after abrupt clozapine withdrawal

Rebound insomnia has been reported upon discontinuation of benzodiazepines. We describe the first case of a sleep polygraphically documented rebound insomnia with an unusual somatic fatigue syndrome after long-term use of clozapine in a 30-year-old schizophrenic male. The withdrawal symptoms occurred the first day after drug discontinuation and could be stopped by readministering clozapine. In our opinion, the sudden occurrence of the withdrawal symptoms cannot be explained by a dopaminergic hypersensitivity or a cholinergic rebound, but indicates an involvement of GABAergic and perhaps antiglutamatergic properties of clozapine.

Clozapine for tardive dyskinesia in adolescents

Thousands of adolescents use neuroleptic drugs over extended periods of time for a wide range of mental disorders. One of the most severe adverse effects of neuroleptic drugs is tardive dyskinesia (TD), for which no successful treatment is currently available. Clozapine is a known atypical neuroleptic drug with few extrapyramidal side effects. It has been suggested that clozapine may be beneficial for the treatment of tardive dyskinesia in adolescents. However, the efficacy of the drug in adolescents is unknown. This report describes the beneficial effect of clozapine on tardive dyskinesia in two adolescents with schizophrenia.

Clozapine treatment of schizophrenia: implications for forensic psychiatry

Clozapine, a new antipsychotic medication, is now the first-line treatment for neuroleptic refractory schizophrenia. Preliminary observations on its efficacy in treating schizophrenic patients with co-morbid substance abuse and, particularly, schizophrenic patients with persistent aggressive behaviour suggests that clozapine may provide a useful treatment option in forensic patient populations. Potential applications of clozapine and management considerations that are relevant to the forensic setting are discussed.