Controlled, double-blind investigation of the clozapine discontinuation symptoms with conversion to either olanzapine or placebo. The Collaborative Crossover Study Group

Clinical Outcomes after Clozapine Discontinuation in Patients with Schizophrenia: A Systematic Review

INTRODUCTION

Clozapine is the gold standard of treatment for patients with treatment-resistant schizophrenia. However, approximately 60% of those patients do not respond to clozapine; moreover, clinical outcomes after clozapine discontinuation are unclear so far. Therefore, we conducted a systematic review to clarify the outcomes after clozapine discontinuation.

METHODS

A systematic literature search was conducted, using MEDLINE and Embase with the following keywords: (clozapine AND (cessation* OR cease* OR withdraw* OR discontinu* OR halt* OR stop* OR switch*) AND (schizophreni* OR schizoaffective)).

RESULTS

A total of 28 clinical studies from 27 articles were identified and included in this systematic review. Three randomized controlled trials reported worsening of psychiatric symptoms. In 10 single-arm studies, the results of worsening and improving psychiatric symptoms were inconsistent. In one large retrospective cohort study, clozapine rechallenge, olanzapine, and antipsychotic polypharmacy had lower rehospitalization rates compared to no medication after clozapine discontinuation. In the other 14 retrospective studies, the vast majority showed worsening of clinical status after clozapine discontinuation. Among five studies on clinical outcomes after clozapine rechallenge, four reported improvements in clinical status in more than half of patients who rechallenged clozapine. The remaining study reported that the clozapine discontinuation-rechallenge group had a worse remission assessment score than the clozapine discontinuation-no rechallenge group.

DISCUSSION

Clinical outcomes generally worsen after clozapine discontinuation. Clozapine rechallenge and olanzapine may be considered following clozapine discontinuation. The outcomes after clozapine discontinuation in clozapine non-responders remain inconclusive; therefore, well-designed studies are warranted.

The effect of second-generation antipsychotic withdrawal on the occurrence of vacuous chewing movements in animal models: A review

INTRODUCTION

Abrupt discontinuation of antipsychotics is associated with an increased risk of adverse events such as extrapyramidal symptoms in humans. In animal models, vacuous chewing movements may occur after antipsychotic discontinuation. We aim to assess vacuous chewing movements after the discontinuation of second-generation antipsychotics in animal models.

METHODS

PubMed, EMBASE, and Web of Science databases were searched for studies since inception until January 2, 2021. In addition, we manually searched references from included and relevant studies. Studies were included if a behavioral assessment of vacuous chewing movements (VCMs) in animal models was performed after discontinuation of a second-generation antipsychotic (SGA). Findings will be reviewed qualitatively and discussed with regard to clinical implications.

RESULTS

5607 studies were screened and five studies were considered eligible for the qualitative analysis. The five studies reported results of behavioral assessments of VCMs after discontinuation of clozapine, olanzapine, and risperidone. VCMs were not reported to be increased after discontinuation of clozapine and olanzapine. However, VCMs were reported to be increased after discontinuation of higher but not lower dosages of risperidone.

DISCUSSION

These findings, based on a limited series of studies, suggest differences in the occurrence of extrapyramidal symptoms between second-generation antipsychotics. More research is needed to determine the magnitude of differences between antipsychotics and implications for clinical practice in humans.

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.

Clozapine-induced gastroesophageal rumination in 22q11.2 Deletion Syndrome. A case report on gastroesophageal side effects management without renouncing clozapine's effectiveness

Despite entailing more severe and uncommon side effects in 22q11.2DS compared to idiopathic schizophrenia, we strongly believe that clozapine should continue to be considered the gold standard for all treatment-resistant schizophrenia, even in 22qDS.

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.

Maintenance treatment with antipsychotic drugs for schizophrenia

BACKGROUND

The symptoms and signs of schizophrenia have been linked to high levels of dopamine in specific areas of the brain (limbic system). Antipsychotic drugs block the transmission of dopamine in the brain and reduce the acute symptoms of the disorder. An original version of the current review, published in 2012, examined whether antipsychotic drugs are also effective for relapse prevention. This is the updated version of the aforesaid review.

OBJECTIVES

To review the effects of maintaining antipsychotic drugs for people with schizophrenia compared to withdrawing these agents.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials including the registries of clinical trials (12 November 2008, 10 October 2017, 3 July 2018, 11 September 2019).

SELECTION CRITERIA

We included all randomised trials comparing maintenance treatment with antipsychotic drugs and placebo for people with schizophrenia or schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data we calculated risk ratios (RR) and their 95% confidence intervals (CIs) on an intention-to-treat basis based on a random-effects model. For continuous data, we calculated mean differences (MD) or standardised mean differences (SMD), again based on a random-effects model.

MAIN RESULTS

The review currently includes 75 randomised controlled trials (RCTs) involving 9145 participants comparing antipsychotic medication with placebo. The trials were published from 1959 to 2017 and their size ranged between 14 and 420 participants. In many studies the methods of randomisation, allocation and blinding were poorly reported. However, restricting the analysis to studies at low risk of bias gave similar results. Although this and other potential sources of bias limited the overall quality, the efficacy of antipsychotic drugs for maintenance treatment in schizophrenia was clear. Antipsychotic drugs were more effective than placebo in preventing relapse at seven to 12 months (primary outcome; drug 24% versus placebo 61%, 30 RCTs, n = 4249, RR 0.38, 95% CI 0.32 to 0.45, number needed to treat for an additional beneficial outcome (NNTB) 3, 95% CI 2 to 3; high-certainty evidence). Hospitalisation was also reduced, however, the baseline risk was lower (drug 7% versus placebo 18%, 21 RCTs, n = 3558, RR 0.43, 95% CI 0.32 to 0.57, NNTB 8, 95% CI 6 to 14; high-certainty evidence). More participants in the placebo group than in the antipsychotic drug group left the studies early due to any reason (at seven to 12 months: drug 36% versus placebo 62%, 24 RCTs, n = 3951, RR 0.56, 95% CI 0.48 to 0.65, NNTB 4, 95% CI 3 to 5; high-certainty evidence) and due to inefficacy of treatment (at seven to 12 months: drug 18% versus placebo 46%, 24 RCTs, n = 3951, RR 0.37, 95% CI 0.31 to 0.44, NNTB 3, 95% CI 3 to 4). Quality of life might be better in drug-treated participants (7 RCTs, n = 1573 SMD -0.32, 95% CI to -0.57 to -0.07; low-certainty evidence); probably the same for social functioning (15 RCTs, n = 3588, SMD -0.43, 95% CI -0.53 to -0.34; moderate-certainty evidence). Underpowered data revealed no evidence of a difference between groups for the outcome 'Death due to suicide' (drug 0.04% versus placebo 0.1%, 19 RCTs, n = 4634, RR 0.60, 95% CI 0.12 to 2.97,low-certainty evidence) and for the number of participants in employment (at 9 to 15 months, drug 39% versus placebo 34%, 3 RCTs, n = 593, RR 1.08, 95% CI 0.82 to 1.41, low certainty evidence). Antipsychotic drugs (as a group and irrespective of duration) were associated with more participants experiencing movement disorders (e.g. at least one movement disorder: drug 14% versus placebo 8%, 29 RCTs, n = 5276, RR 1.52, 95% CI 1.25 to 1.85, number needed to treat for an additional harmful outcome (NNTH) 20, 95% CI 14 to 50), sedation (drug 8% versus placebo 5%, 18 RCTs, n = 4078, RR 1.52, 95% CI 1.24 to 1.86, NNTH 50, 95% CI not significant), and weight gain (drug 9% versus placebo 6%, 19 RCTs, n = 4767, RR 1.69, 95% CI 1.21 to 2.35, NNTH 25, 95% CI 20 to 50).

AUTHORS' CONCLUSIONS

For people with schizophrenia, the evidence suggests that maintenance on antipsychotic drugs prevents relapse to a much greater extent than placebo for approximately up to two years of follow-up. This effect must be weighed against the adverse effects of antipsychotic drugs. Future studies should better clarify the long-term morbidity and mortality associated with these drugs.

Clozapine Combination and Augmentation Strategies in Patients With Schizophrenia -Recommendations From an International Expert Survey Among the Treatment Response and Resistance in Psychosis (TRRIP) Working Group

BACKGROUND

Evidence for the management of inadequate clinical response to clozapine in treatment-resistant schizophrenia is sparse. Accordingly, an international initiative was undertaken with the aim of developing consensus recommendations for treatment strategies for clozapine-refractory patients with schizophrenia.

METHODS

We conducted an online survey among members of the Treatment Response and Resistance in Psychosis (TRRIP) working group. An agreement threshold of ≥75% (responses "agree" + "strongly agree") was set to define a first-round consensus. Questions achieving agreement or disagreement proportions of >50% in the first round, were re-presented to develop second-round final consensus recommendations.

RESULTS

Forty-four (first round) and 49 (second round) of 63 TRRIP members participated. Expert recommendations at ≥75% agreement included raising clozapine plasma levels to ≥350 ng/ml for refractory positive, negative, and mixed symptoms. Where plasma level-guided dose escalation was ineffective for persistent positive symptoms, waiting for a delayed response was recommended. For clozapine-refractory positive symptoms, combination with a second antipsychotic (amisulpride and oral aripiprazole) and augmentation with ECT achieved consensus. For negative symptoms, waiting for a delayed response was recommended, and as an intervention for clozapine-refractory negative symptoms, clozapine augmentation with an antidepressant reached consensus. For clozapine-refractory suicidality, augmentation with antidepressants or mood-stabilizers, and ECT met consensus criteria. For clozapine-refractory aggression, augmentation with a mood-stabilizer or antipsychotic medication achieved consensus. Generally, cognitive-behavioral therapy and psychosocial interventions reached consensus.

CONCLUSIONS

Given the limited evidence from randomized trials of treatment strategies for clozapine-resistant schizophrenia (CRS), this consensus-based series of recommendations provides a framework for decision making to manage this challenging clinical situation.

Antipsychotics and the risk of diabetes: A general data review

Recently, attention has focused on a potential link between schizophrenia and diabetes, with speculation that this potential associationis stronger in patients who are prescribed atypical antipsychotics. Pharmacoepidemiological studies can help to evaluate this potential association. Source data on the incidence of diabetes in patients treated with antipsychotics is available in the FDA MedWatch database, prescription claims databases and other patient registries. These data indicate that antipsychotic drugs may increase the risk of developing diabetes and that there may be an interaction with age. However, current data are insufficient to accurately assess potential differences in the risk of diabetes between users of individual antipsychotic medications. In addition, antipsychotic treatment-emergent diabetes has several distinct features, notably relating to age of onset, gender ratio, rate of deterioration of glycaemic control, and independence from initial treatment emergent weight gain. Nonetheless, guidelines for the control of risk factors for diabetes developed for the general population appear to be applicable to patients with schizophrenia.

Antipsychotic Withdrawal Symptoms: A Systematic Review and Meta-Analysis

OBJECTIVE

Avoiding withdrawal symptoms following antipsychotic discontinuation is an important factor when planning a safe therapy. We performed a systematic review and meta-analysis concerning occurrence of withdrawal symptoms after discontinuation of antipsychotics.

DATA SOURCES

We searched the databases CENTRAL, Pubmed, and EMBASE with no restriction to the beginning of the searched time period and until October 1, 2019 (PROSPERO registration no. CRD42019119148).

STUDY SELECTION

Of the 18,043 screened studies, controlled and cohort trials that assessed withdrawal symptoms after discontinuation of oral antipsychotics were included in the random-effects model. Studies that did not implement placebo substitution were excluded from analyses. The primary outcome was the proportion of individuals with withdrawal symptoms after antipsychotic discontinuation. We compared a control group with continued antipsychotic treatment in the assessment of odds ratio and number needed to harm (NNH).

DATA EXTRACTION

We followed guidelines by the Cochrane Collaboration, PRISMA, and MOOSE.

RESULTS

Five studies with a total of 261 individuals were included. The primary outcome, proportion of individuals with withdrawal symptoms after antipsychotic discontinuation, was 0.53 (95% CI, 0.37-0.70; I² = 82.98%, P < 0.01). An odds ratio of 7.97 (95% CI, 2.39-26.58; I² = 82.7%, P = 0.003) and NNH of 3 was calculated for the occurrence of withdrawal symptoms after antipsychotic discontinuation.

CONCLUSION

Withdrawal symptoms appear to occur frequently after abrupt discontinuation of an oral antipsychotic. The lack of randomized controlled trials with low risk of bias on antipsychotic withdrawal symptoms highlights the need for further research.

Closure beyond clozapine: successfully averting rebound symptoms in a patient with schizoaffective disorder and agranulocytosis

SUMMARY

'Rebound' or 'withdrawal' symptoms are frequently observed after a sudden discontinuation of clozapine. We describe a patient with treatment-resistant schizoaffective disorder who developed agranulocytosis on clozapine but was successfully switched to treatment with olanzapine with no deterioration in her condition. We put forward three possible theories which may have accounted for the lack of rebound symptoms in this patient: the pharmacological profile of olanzapine, the anticholinergic effects of hyoscine hydrobromide, and the possibility that this patient may not be treatment-resistant and so have a reduced risk of rebound psychosis due to displaying a different pathophysiology.

DECLARATION OF INTEREST

None.

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.

Retrospective analysis of risk factors in patients with treatment-emergent diabetes during clinical trials of antipsychotic medications

Aims

In this retrospective analysis, we assessed the short-term risk of treatment-emergent diabetes (TED) among patients with schizophrenia during clinical trials of antipsychotic medications.

Method

From a non-diabetic cohort of patients with schizophrenia (n=5013), the relationship between baseline non-fasting glucose measurement, presence at baseline of risk factors for diabetes, weight gain and therapy assignment on the risk of treatment-emergent diabetes were assessed.

Results

At the baseline assessment, about a third of patients identified with TED during treatment had non-fasting glucose levels over 7.8 mmol/l and two-thirds had multiple diabetes risk factors. Both baseline non-fasting glucose level and the presence of multiple pre-existing diabetes risk factors appeared to have a major impact on the risk of developing diabetes.

Conclusions

Overall, risk factors for diabetes in patients with schizophrenia overlap those in the general population. The results also suggest that many patients identified with TED might have had pre-existing glycaemic abnormalities or a high baseline burden of diabetes risk factors.

Atypical neuroleptic malignant syndrome in patients treated with aripiprazole and clozapine: a case-series study and short review

OBJECTIVES

Neuroleptic malignant syndrome (NMS) requires emergency treatment and can be fatal. Combined aripiprazole and clozapine therapy is rarely used in clinical settings, and NMS related this combination still lacks evaluation. Herein, we present two cases of atypical NMS treated with aripiprazole and clozapine.

METHODS

Case 1 was a schizophrenic male with a history of NMS under treatment with aripiprazole 20 mg. He was hospitalized and maintained with aripiprazole 5 mg and clozapine 225 mg. On the 25th day, atypical NMS occurred with rigidity, elevated creatine kinase, and stupor, which subsided with supportive therapy. He was discharged under treatment with aripiprazole 15 mg and fluoxetine 60 mg. Case 2 was a female with schizoaffective disorder without a history of NMS. She was hospitalized and maintained with clozapine 50 mg and aripirazole 30 mg. On the 11th day, atypical NMS occurred with mild fever, delirium, and rigidity, which subsided under supportive therapy.

RESULTS AND CONCLUSIONS

Our cases highlight the atypical features of NMS in patients being treated with combined ari-piprazole and clozapine. Consciousness change, modest elevation of creatine kinase, and leukocytosis were the most consistent findings; hyperthermia accounts for only some of the cases. This is a reminder of the importance of earlier detection of the soft signs and atypical features of NMS under this combined treatment.

Antipsychotic discontinuation syndromes: a narrative review of the evidence and its integration into Australian mental health nursing textbooks

In light of the high number of people discontinuing antipsychotics each year, it is essential that nurses develop a robust understanding of all aspects of the discontinuation experience. While there is a large body of published work documenting post-discontinuation relapse rates, less is known about other aspects of the discontinuation experience. This paper presents the results of a narrative review of international studies of antipsychotic discontinuation syndromes and their relevance to nursing practice. Four key mental health nursing textbooks used in student nurse education in Australia are examined to assess how this evidence has been incorporated into clinical recommendations. This review finds that the evidence for discontinuation syndromes could be more widely disseminated and applied than it is at present. Strikingly, this evidence has not been incorporated into key mental health nursing textbooks in Australia at all. Slow integration into nursing published work may be influenced by a number of clinical and research uncertainties. We consider the impact of this silence on key nursing roles of psycho-education and adverse event monitoring during antipsychotic discontinuation periods. Further robust research should be conducted into discontinuation syndromes as a matter of urgency. Given the high number of consumers potentially impacted upon by discontinuation syndromes, nurse authors and educators should consider revising key nursing textbooks to include the currently available information about discontinuation syndromes.

Effects of drop-out on efficacy estimates in five Cochrane reviews of popular antipsychotics for schizophrenia

OBJECTIVE

Our aim was to find out how Cochrane reviews of five popular or frequently prescribed second-generation antipsychotics in the UK (olanzapine, risperidone, quetiapine, amisulpride and aripiprazole) approached the problem of high drop-out in placebo-controlled trials.

METHOD

We examined the following: (i) whether reviews included data from studies with a level of drop-out exceeding their stated exclusion criterion; (ii) the level of missing data each efficacy outcome in each review relied upon; and (iii) impact of excluding studies with high drop-out.

RESULTS

All reviews included data they stated they would exclude because of unacceptable levels of attrition, four (risperidone, olanzapine, amisulpride, aripiprazole) without clear acknowledgement or justification. Several reviews also excluded data from a number of relatively low-attrition studies because of missing standard deviations.

CONCLUSION

Cochrane reviews of five popular antipsychotics for schizophrenia misrepresented the available evidence on their efficacy. The impact of including high-attrition studies was difficult to quantify because of the exclusion of relevant low-attrition studies. Further analysis of the efficacy of these drugs in studies with acceptable rates of attrition is required. To reduce the problem of high attrition, trialists should gather follow-up data from people who leave the double-blind process early.

Maintenance treatment with antipsychotic drugs for schizophrenia

BACKGROUND

The symptoms and signs of schizophrenia have been firmly linked to high levels of dopamine in specific areas of the brain (limbic system). Antipsychotic drugs block the transmission of dopamine in the brain and reduce the acute symptoms of the disorder. This review examined whether antipsychotic drugs are also effective for relapse prevention.

OBJECTIVES

To review the effects of maintaining antipsychotic drugs for people with schizophrenia compared to withdrawing these agents.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Specialised Register (November 2008), with additional searches of MEDLINE, EMBASE and clinicaltrials.gov (June 2011).

SELECTION CRITERIA

We included all randomised trials comparing maintenance treatment with antipsychotic drugs and placebo for people with schizophrenia or schizophrenia-like psychoses.

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 random-effects model. For continuous data, we calculated mean differences (MD) or standardised mean differences (SMD) again based on a random-effects model.

MAIN RESULTS

The review currently includes 65 randomised controlled trials (RCT(s)) and 6493 participants comparing antipsychotic medication with placebo. The trials were published from 1959 to 2011 and their size ranged between 14 and 420 participants. In many studies the methods of randomisation, allocation and blinding were poorly reported. Although this and other potential sources of bias limited the overall quality, the efficacy of antipsychotic drugs for maintenance treatment in schizophrenia was clear. Antipsychotic drugs were significantly more effective than placebo in preventing relapse at seven to 12 months (primary outcome; drug 27%, placebo 64%, 24 RCT(s), n=2669, RR 0.40 CI 0.33 to 0.49, number needed to treat for an additional beneficial outcome (NNTB 3 CI 2 to 3). Hospitalisation was also reduced, however, the baseline risk was lower (drug 10%, placebo 26%, 16 RCT(s), n=2090, RR 0.38 CI 0.27 to 0.55, NNT 5 CI 4 to 9). More participants in the placebo group than in the antipsychotic drug group left the studies early due to any reason (at 7-12 months: drug 38%, placebo 66%, 18 RCT(s), n=2420, RR 0.55 CI 0.46 to 0.66, NNTB 4 CI 3 to 5) and due to inefficacy of treatment (at 7-12 months: drug 20%, placebo 50%, 18 RCT(s), n=2420, RR 0.36 CI 0.28 to 0.45, NNTB 3 CI 2 to 4). Quality of life was better in drug-treated participants (3 RCT(s), n=527, SMD -0.62 CI -1.15 to -0.09). Conversely, antipsychotic drugs as a group and irrespective of duration, were associated with more participants experiencing movement disorders (e.g. at least one movement disorder: drug 16%, placebo 9%, 22 RCT(s), n=3411, RR 1.55 CI 1.25 to 1.93, NNTH 25 CI 13 to 100), sedation (drug 13%, placebo 9%, 10 RCT(s), n=146, RR 1.50 CI 1.22 to 1.84, number needed to treat for an additional harmful outcome (NNTH) not significant) and weight gain (drug 10%, placebo 6%, 10 RCT(s), n=321, RR 2.07 CI 1.31 to 3.25, NNTH 20 CI 14 to 33). The results of the primary outcome were robust in a number of subgroup, meta-regression and sensitivity analyses, the main exception being that the drug-placebo difference in longer trials was smaller than in shorter trials.

AUTHORS' CONCLUSIONS

The results clearly demonstrate the superiority of antipsychotic drugs compared to placebo in preventing relapse. This effect must be weighed against the side effects of antipsychotic drugs. Future studies should focus on outcomes of social participation and clarify the long-term morbidity and mortality associated with these drugs.

An Unusual Cause of Delirium in a Psychiatric Patient: Abrupt Clozapine Discontinuation

Rapid clinical deteriorations have been reported after abrupt discontinuation of clozapine. A 42-year-old psychiatric patient presented with ingestion of hand-disinfectant solutions causing transient impairment of his conscious level. His clozapine therapy was discontinued for a short period of time and he developed delirium with normal results of investigations for underlying organic causes. His delirium resolved rapidly after the reintroduction of clozapine. The withdrawal effects of abrupt discontinuation of clozapine are discussed in this article.

Dropout rates in randomized clinical trials of antipsychotics: a meta-analysis comparing first- and second-generation drugs and an examination of the role of trial design features

Dropout is often used as an outcome measure in clinical trials of antipsychotic medication. Previous research is inconclusive regarding (a) differences in dropout rates between first- and second-generation antipsychotic medications and (b) how trial design features reduce dropout. Meta-analysis of randomized controlled trials (RCTs) of antipsychotic medication was conducted to compare dropout rates for first- and second-generation antipsychotic drugs and to examine how a broad range of design features effect dropout. Ninety-three RCTs that met inclusion criteria were located (n = 26 686). Meta-analytic random effects models showed that dropout was higher for first- than second-generation drugs (odds ratio = 1.49, 95% confidence interval: 1.31-1.66). This advantage persisted after removing study arms with excessively high dosages, in flexible dose studies, studies of patients with symptom exacerbation, nonresponder patients, inpatients, and outpatients. Mixed effects models for meta-analysis were used to identify design features that effected dropout and develop formulae to derive expected dropout rates based on trial design features, and these assigned a pivotal role to duration. Collectively, dropout rates are lower for second- than first-generation antipsychotic drugs and appear to be partly explained by trial design features thus providing direction for future trial design.

Olanzapine withdrawal/discontinuation-induced hyperthermia in rats

In female rats olanzapine (4 mg/kg b.i.d., i.p.) induced acute hypothermia, followed by very rapid full tolerance. With more prolonged treatment (over > 10 days) the hypothermic effect of olanzapine was reinstated. Subsequent withdrawal after 18 days of treatment induced very rapid onset (within 1 day) hyperthermia, which was time limited, dissipating completely over 3-4 days. These findings are similar to previous findings with clozapine [Goudie A Smith J Robertson A Cavanagh C (1999). Clozapine as a drug of dependence. Psychopharmacology; 142: 369-374.]. Although the mechanism(s) involved in the secondary hypothermic effect of olanzapine are, at present, unclear; the withdrawal hyperthermia observed represents the first report of a clear discontinuation effect of olanzapine. Such discontinuation effects are probably observed with many antipsychotic drugs. Since they have been suggested to facilitate relapse to psychosis and to interfere with subsequent clinical responses to antipsychotics, they merit further detailed analysis in both clinical and preclinical studies.

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

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

Does antipsychotic withdrawal provoke psychosis? Review of the literature on rapid onset psychosis (supersensitivity psychosis) and withdrawal-related relapse

OBJECTIVE

To examine the evidence that discontinuation of long-term antipsychotic medication, including clozapine, may provoke a psychotic episode.

METHOD

Databases were searched and citations scrutinised.

RESULTS

Evidence for a rapid onset psychosis (supersensitivity psychosis) following clozapine withdrawal was found and weaker evidence that this might occur with some other antipsychotic drugs. Some cases were reported in people without a psychiatric history. It appears that the psychosis may be a feature of drug withdrawal rather than the re-emergence of an underlying illness, at least in some patients. Meta-analyses of withdrawal studies have suggested that antipsychotic discontinuation may also increase the risk of relapse over and above the risk because of the underlying disorder, but not all individual studies show this effect. Mechanisms may relate to brain adaptations to long-term drug use but data are sparse.

CONCLUSION

These effects require further urgent research. Interventions to reduce morbidity after drug withdrawal need to be developed.

Combating psychosis in Parkinson's disease patients: the use of antipsychotic drugs

Parkinson's disease (PD) patients commonly experience psychotic symptoms, with the most frequent manifestation being visual hallucinations. In PD, psychosis is predominantly drug induced and an important issue for clinicians to address as it increases the risk of nursing home placement as well as mortality. This review summarises the current knowledge regarding the clinical manifestations, pathophysiology and risk factors for drug-induced psychosis in patients with PD and focuses on treatment, especially with regard to the atypical antipsychotics.

Effect of anticholinergics in preventing acute deterioration in patients undergoing abrupt clozapine withdrawal

BACKGROUND

The most serious adverse effect of clozapine, agranulocytosis, was described for the first time in Finland in 1975. It caused the immediate withdrawal of clozapine from the market and immediate discontinuation of this medication in all patients. It is now known that abrupt withdrawal of clozapine may cause a rapid deterioration in psychotic symptoms.

OBJECTIVE

The aim of this retrospective study was to investigate the effect of abrupt clozapine withdrawal on psychiatric patients, and to examine whether anticholinergic drugs are effective in preventing acute deterioration.

MATERIALS AND METHODS

We reviewed the hospital case records from Pitkäniemi Psychiatric Hospital, Tampere, Finland, of the 28 patients with schizophrenia who had been receiving clozapine and from whom it was abruptly withdrawn due to the withdrawal of the drug from the market in the summer of 1975. We assessed the incidence of deterioration and whether or not patients in whom this occurred were receiving anticholinergic drugs.

RESULTS

We found a rapid deterioration after clozapine withdrawal in almost half (46.4%; n = 13) of the patients. Patients receiving anticholinergic drugs (such as antiparkinsonians, tricyclic antidepressants and antipsychotics with anticholinergic properties) were significantly less likely to deteriorate than those not receiving these drugs (21.4% vs 71.4%, p = 0.008). The condition of the patients who deteriorated was poor for up to 1 month after discontinuation, but had improved slightly by the end of 1975.

CONCLUSION

Anticholinergic medication should be considered for preventing possible symptom deterioration when clozapine is abruptly discontinued.

An analysis of the effect of funding source in randomized clinical trials of second generation antipsychotics for the treatment of schizophrenia

OBJECTIVE

The effect of funding source on the outcome of randomized controlled trials has been investigated in several medical disciplines; however, psychiatry has been largely excluded from such analyses. In this article, randomized controlled trials of second generation antipsychotics in schizophrenia are reviewed and analyzed with respect to funding source (industry vs. non-industry funding).

METHOD

A literature search was conducted for randomized, double-blind trials in which at least one of the tested treatments was a second generation antipsychotic. In each study, design quality and study outcome were assessed quantitatively according to rating scales. Mean quality and outcome scores were compared in the industry-funded studies and non-industry-funded studies. An analysis of the primary author's affiliation with industry was similarly performed.

RESULTS

Results of industry-funded studies significantly favored second generation over first generation antipsychotics when compared to non-industry-funded studies. Non-industry-funded studies showed a trend toward higher quality than industry-funded studies; however, the difference between the two was not significant. Also, within the industry-funded studies, outcomes of trials involving first authors employed by industry sponsors demonstrated a trend toward second generation over first generation antipsychotics to a greater degree than did trials involving first authors employed outside the industry (p=0.05).

CONCLUSIONS

While the retrospective design of the study limits the strength of the findings, the data suggest that industry bias may occur in randomized controlled trials in schizophrenia. There appears to be several sources by which bias may enter clinical research, including trial design, control of data analysis and multiplicity/redundancy of trials.

Switching atypical antipsychotics: a review

BACKGROUND

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

OBJECTIVE

To review the data on switching and atypical antipsychotics.

METHODS

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

RESULTS

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

CONCLUSION

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

Clozapine withdrawal symptoms in a Parkinson's disease patient

Abrupt clozapine withdrawal can cause rebound psychosis and severe somatic symptoms in psychiatric patients. We report on the case of an advanced Parkinson's disease patient who developed myoclonus, tremor, rigidity, hyperreflexia, and stupor after abrupt clozapine withdrawal. The patient's symptoms resolved with treatment with cyproheptadine. This clinical picture suggests serotonergic rebound as an explanation for the patient's symptoms, although other pharmacological mechanisms are possible. Clozapine should be gradually withdrawn over a period of 1 to 2 weeks when possible, and abruptly discontinued only when necessary.

Olanzapine as alternative therapy for patients with haloperidol-induced extrapyramidal symptoms: results of a multicenter, collaborative trial in Latin America

Conventional antipsychotic agents can induce extrapyramidal symptoms (EPS) that may be alleviated by switching patients to novel agents such as olanzapine. Patients with schizophrenia and related disorders (ICD-10) who were taking haloperidol (N = 94; mean dose = 12.7 mg/day) and had EPS (Simpson-Angus Scale [SAS] > 3) were directly switched to 6 weeks of open-label olanzapine treatment (mean dose = 11.4 mg/day). There were significant mean improvements (p <0.001 for all measurements) from baseline to endpoint on the SAS (-9.69+/-5.33; percentage change, 87.2%), the Barnes Akathisia Scale (-1.00+/-1.19; percentage change, 82.5%), and the Abnormal Involuntary Movement Scale (-1.48+/-2.89; percentage change, 81.1%), and anticholinergic use decreased from 47.9% to 12.8% (mean baseline to endpoint change: -1.52+/-1.91-mg equivalents of benztropine; p < 0.001). Significant mean baseline to endpoint improvements (p < 0.001 for all measurements) were observed on the Positive and Negative Syndrome Scale (PANSS; -25.28+/-18.67; percentage change, 30.3%), the PANSS-extracted Brief Psychiatric Rating Scale (0-6 scale, -13.41+/-10.16; percentage change, 54.4%), and the Clinical Global Impressions Severity scale (-1.16+/-1.19; percentage change, 26.4%). Spontaneously reported treatment- emergent adverse events with a greater than 5% incidence were somnolence (16.0%), increased appetite (14.9%), weight gain (11.7%), headache (8.5%), anxiety (7.4%), dizziness (6.4%), and insomnia (5.3%). Criteria for a successful switch were met by 90.5% of patients. Psychotic symptom exacerbation was experienced by 30.9% of patients at any time during the study and by 11.7% of patients at endpoint. Results suggest that a direct switch to olanzapine is a therapeutic option when patients with haloperidol-induced EPS are unable to tolerate a more gradual switch.

Possible serotonin syndrome associated with clomipramine after withdrawal of clozapine

OBJECTIVE

To report on the possible development of serotonin syndrome in a patient receiving clomipramine after clozapine was withdrawn from the treatment regimen.

CASE REPORT

A 44-year-old white man with a 23-year history of undifferentiated schizophrenia and obsessive-compulsive behavior had been treated with clozapine and clomipramine for several years. He tolerated both agents together well, with the exception of experiencing chronic constipation. Clomipramine was tapered and reduced to 50 mg over a period of 10 days. A worsening of ritualistic behavior was noted, and the clomipramine dosage was increased to 150 mg/d over 14 days. Simultaneously with the clomipramine dosage increase, clozapine was tapered and stopped ever a period of 19 days. The day after clozapine was stopped, while he was still receiving clomipramine 150 mg/d, he began behaving oddly, started sweating profusely, shivering, and became tremulous, agitated, and confused. He was diagnosed with possible serotonin syndrome; his symptoms resolved after clomipramine was stopped but before clozapine was restarted eight days later.

DISCUSSION

There are similarities in symptoms between serotonin syndrome and clozapine withdrawal. This article discusses the reasons why this case may represent serotonin syndrome rather than clozapine withdrawal and the possible pharmacologic mechanisms involved.

CONCLUSIONS

Clinicians should be aware that removing a serotonin-2a (S-HT2a) antagonist 1mm a treatment regimen including an agent that increases serotonin in the synaptic cleft may worsen clozapine withdrawal or potentially result in serious adverse drug reactions, such as serotonin syndrome.