Quality improvement through audit: Zuclopenthixol acetate prescribing, monitoring and patient outcomes in a regional health service.

OBJECTIVE: Prescribers' expectations of Zuclopethixol Acetate's (ZA) efficacy and tolerability are shaped by clinical experience and organisational culture; however, these expectations may not be consistent with current evidence and best practice. METHODS: Quality improvement project (QIP) through a process audit of ZA prescribing, monitoring and patient outcomes (adverse events) in order to identify issues requiring intervention to align with service standards and practices. RESULTS: QIP interventions resulted in a statistically significant shift in psychiatrist oversight, identifying high dose ZA with adverse outcomes and cessation of prescribing/administration within the Emergency Department. Clinically significant changes in patterns of prescribing were observed between pre-post intervention audits. CONCLUSION: Entrenching an evidence-based QIP approach to clinical practice can effect clinically significant patterns of practice change to improve safe prescribing and drug monitoring.

Buprenorphine/naloxone (Suboxone®) withdrawal may facilitate antipsychotic-induced priapism. A case report.

INTRODUCTION: Priapism is defined as a prolonged penile erection in absence of sexual arousal, leading also to serious sexual and urological problems such as erectile dysfunction and penile fibrosis. Amongst many different etiologies, priapism may be caused by a wide range of antipsychotic medications, mainly due to the α1-adrenergic receptor antagonism. On the other hand, only a couple of cases of opioid compounds have been linked to the onset of priapism, with evidence coming only from methadone and buprenorphine. Here we describe the case of a patient treated with antipsychotics who developed priapism four times following rapid discontinuation of buprenorphine/naloxone (Suboxone®). CASE PRESENTATION: S.C. is a 30-year-old Caucasian man suffering from chronic buprenorphine/naloxone (Suboxone®) abuse, borderline personality disorder, antisocial traits, and multiple suicide attempts. During the acute and the first part of post-acute Suboxone® withdrawal, four episodes of priapism developed while he was treated with clotiapine, clozapine, and chlorpromazine. However, after the last episode of priapism, despite he was either on haloperidol or zuclopenthixol and chlorpromazine, no other urological event occurred during the following 6 months of observation. CONCLUSIONS: As opioids may have dampened the patient's sexual function due to chronic consumption, a rapid drug suspension coupled with an antipsychotic therapy might have created the conditions to facilitate the occurrence of close clustered priapism events.

Antipsychotic-Induced Laryngeal Dystonia.

We present the case of a young gentleman with diagnoses of bipolar affective disorder, high body mass index, and obstructive sleep apnoea. He was commenced on zuclopenthixol due to an inadequate response to quetiapine, but this swiftly led to marked physical health deterioration including shortness of breath, back pain, tachycardia, tachypnoea, and hypoxia. He was urgently transferred to hospital where he required intubation and intensive care admission. AFTER excluding other causes, it was felt that commencing zuclopenthixol had induced laryngo-pharyngeal dystonia leading to upper airway compromise and severely impaired respiratory function. He progressively recovered after zuclopenthixol was stopped, and he was transferred back to the psychiatric hospital after eight days. THIS case highlights the potential challenges in diagnosing this rare but potentially fatal reaction to antipsychotics. We review the available literature on other cases including a potential interaction between typical antipsychotics and serotonin-specific reuptake inhibitors. Psychiatrists and emergency physicians should be aware of this condition and be alert in considering the administration of anticholinergics, which could be a simple yet life-saving intervention.

Neuroleptic malignant syndrome following reintroduction of an antipsychotic after overdose.

Neuroleptic malignant syndrome (NMS) is a potentially lethal adverse drug reaction. We report a case of NMS potentially induced by dehydration in a female patient suffering from schizoaffective disorder. We discuss possible aetiologies and triggering factors alongside the existing literature.

Zuclopenthixol dihydrochloride for schizophrenia.

BACKGROUND: Oral zuclopenthixol dihydrochloride (Clopixol) is an anti-psychotic treatment for people with psychotic symptoms, especially those with schizophrenia. It is associated with neuroleptic malignant syndrome, a prolongation of the QTc interval, extra-pyramidal reactions, venous thromboembolism and may modify insulin and glucose responses. OBJECTIVES: To determine the effects of zuclopenthixol dihydrochloride for treatment of schizophrenia. SEARCH METHODS: We searched the Cochrane Schizophrenia Group's Trials Register (latest search 09 June 2015). There were no language, date, document type, or publication status limitations for inclusion of records in the register. SELECTION CRITERIA: All randomised controlled trials (RCTs) focusing on zuclopenthixol dihydrochloride for schizophrenia. We included trials meeting our inclusion criteria and reporting useable data. DATA COLLECTION AND ANALYSIS: We extracted data independently. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For continuous data, we estimated the mean difference (MD) between groups and its 95% CI. We employed a random-effect model for analyses. We assessed risk of bias for included studies and created 'Summary of findings' tables using GRADE. MAIN RESULTS: We included 20 trials, randomising 1850 participants. Data were reported for 12 comparisons, predominantly for the short term (up to 12 weeks) and inpatient populations. Overall risk of bias for included studies was low to unclear.Data were unavailable for many of our pre-stated outcomes of interest. No data were available, across all comparisons, for death, duration of stay in hospital and general functioning.Zuclopenthixol dihydrochloride versus: 1. placeboMovement disorders (EPSEs) were similar between groups (1 RCT, n = 28, RR 6.07 95% CI 0.86 to 43.04 very low-quality evidence). There was no clear difference in numbers leaving the study early (2 RCTs, n = 100, RR 0.29, 95% CI 0.01 to 6.60, very low-quality evidence). 2. chlorpromazineNo clear differences were found for the outcomes of global state (average CGI-SI endpoint score) (1 RCT, n = 60, MD 0.00, 95% CI -0.49 to 0.49) or movement disorders (EPSEs) (3 RCTs, n = 199, RR 0.94, 95% CI 0.61 to 1.45), both very low-quality evidence. More people left the study early for any reason from the zuclopenthixol group (6 RCTs, n = 766, RR 0.54, 95% CI 0.36 to 0.81, low-quality evidence). 3. chlorprothixeneThere was no clear difference in numbers leaving the study early for any reason (1 RCT, n = 20, RR 1.00, 95% CI 0.34 to 2.93, very low-quality evidence). 4. clozapineNo useable data were presented. 5. haloperidolNo clear differences between treatment groups were found for the outcomes global state score (average CGI endpoint score) (1 RCT, n = 49, MD 0.13, 95% CI -0.30 to 0.55) or leaving the study early (2 RCTs, n = 141, RR 0.99, 95% CI 0.72 to 1.35), both very low-quality evidence. 6. perphenazineThose receiving zuclopenthixol were more likely to require medication in the short term for EPSEs than perphenazine (1 RCT, n = 50, RR 1.90, 95% CI 1.12 to 3.22, very low-quality evidence). Similar numbers left the study early (2 RCTs, n = 104, RR 0.63, 95% CI 0.27 to 1.47, very low-quality evidence). 7. risperidoneThose receiving zuclopenthixol were more likely to require medications for EPSEs than risperidone (1 RCT, n = 98,RR 1.92, 95% CI 1.12 to 3.28, very low quality evidence). There was no clear difference in numbers leaving the study early ( 3 RCTs, n = 154, RR 1.30, 95% CI 0.84 to 2.02) or in mental state (average PANSS total endpoint score) (1 RCT, n = 25, MD -3.20, 95% CI -7.71 to 1.31), both very low-quality evidence). 8. sulpirideNo clear differences were found for global state (average CGI endpoint score) ( 1 RCT, n = 61, RR 1.18, 95% CI 0.49 to 2.85, very low-quality evidence), requiring hypnotics/sedatives (1 RCT, n = 61, RR 0.60, 95% CI 0.27 to 1.32, very low-quality evidence) or leaving the study early (1 RCT, n = 61, RR 2.07 95% CI 0.97 to 4.40, very low-quality evidence). 9. thiothixeneNo clear differences were found for the outcomes of 'global state (average CGI endpoint score) (1 RCT, n = 20, RR 0.50, 95% CI 0.17 to 1.46) or leaving the study early (1 RCT, n = 20, RR 0.57, 95% CI 0.24 to 1.35), both very low-quality evidence). 10. trifluoperazineNo useable data were presented. 11. zuclopenthixol depotThere was no clear difference in numbers leaving the study early (1 RCT, n = 46, RR 1.95, 95% CI 0.36 to 10.58, very low-quality evidence). 12. Zuclopenthixol dihydrochloride (cis z isomer) versus zuclopenthixol (cis z/trans e isomer)There were no clear differences in reported side-effects ( 1 RCT, n = 57, RR 1.34, 95% CI 0.82 to 2.18, very low-quality evidence) and in numbers leaving the study early (4 RCTs, n = 140, RR 2.15, 95% CI 0.49 to 9.41, very low-quality evidence). AUTHORS' CONCLUSIONS: Zuclopenthixol dihydrochloride appears to cause more EPSEs than clozapine, risperidone or perphenazine, but there was no difference in EPSEs when compared to placebo or chlorpromazine. Similar numbers required hypnotics/sedatives when zuclopenthixol dihydrochloride was compared to sulpiride, and similar numbers of reported side-effects were found when its isomers were compared. The other comparisons did not report adverse-effect data.Reported data indicate zuclopenthixol dihydrochloride demonstrates no difference in mental or global states compared to placebo, chlorpromazine, chlorprothixene, clozapine, haloperidol, perphenazine, sulpiride, thiothixene, trifluoperazine, depot and isomers. Zuclopenthixol dihydrochloride, when compared with risperidone, is favoured when assessed using the PANSS in the short term, but not in the medium term.The data extracted from the included studies are mostly equivocal, and very low to low quality, making it difficult to draw firm conclusions. Prescribing practice is unlikely to change based on this meta-analysis. Recommending any particular course of action about side-effect medication other than monitoring, using rating scales and clinical assessment, and prescriptions on a case-by-case basis, is also not possible.There is a need for further studies covering this topic with more antipsychotic comparisons for currently relevant outcomes.

Frontal D2/3 Receptor Availability in Schizophrenia Patients Before and After Their First Antipsychotic Treatment: Relation to Cognitive Functions and Psychopathology.

BACKGROUND: We have previously reported associations between frontal D2/3 receptor binding potential positive symptoms and cognitive deficits in antipsychotic-naïve schizophrenia patients. Here, we examined the effect of dopamine D2/3 receptor blockade on cognition. Additionally, we explored the relation between frontal D2/3 receptor availability and treatment effect on positive symptoms. METHODS: Twenty-five antipsychotic-naïve first-episode schizophrenia patients were examined with the Positive and Negative Syndrome Scale, tested with the cognitive test battery Cambridge Neuropsychological Test Automated Battery, scanned with single-photon emission computerized tomography using the dopamine D2/3 receptor ligand [(123)I]epidepride, and scanned with MRI. After 3 months of treatment with either risperidone (n=13) or zuclopenthixol (n=9), 22 patients were reexamined. RESULTS: Blockade of extrastriatal dopamine D2/3 receptors was correlated with decreased attentional focus (r = -0.615, P=.003) and planning time (r = -0.436, P=.048). Moreover, baseline frontal dopamine D2/3 binding potential and positive symptom reduction correlated positively (D2/3 receptor binding potential left frontal cortex rho = 0.56, P=.003; D2/3 receptor binding potential right frontal cortex rho = 0.48, P=.016). CONCLUSIONS: Our data support the hypothesis of a negative influence of D2/3 receptor blockade on specific cognitive functions in schizophrenia. This is highly clinically relevant given the well-established association between severity of cognitive disturbances and a poor functional outcome in schizophrenia. Additionally, the findings support associations between frontal D2/3 receptor binding potential at baseline and the effect of antipsychotic treatment on positive symptoms.

Zuclopenthixol versus placebo for schizophrenia.

BACKGROUND: Zuclopenthixol is an older antipsychotic that has three distinct formulations (zuclopenthixol dihydrochloride, zuclopenthixol acetate or Acuphase and zuclopenthixol decanoate). Although it has been in common use for many years no previous systematic review of its efficacy compared to placebo in schizophrenia has been undertaken. OBJECTIVES: To evaluate the effectiveness of all formulations of zuclopenthixol when compared with a placebo in schizophrenia. SEARCH METHODS: On 6 November 2013 and 20 October 2015, we searched the Cochrane Schizophrenia Group Trials Register, which is based on regular searches of MEDLINE, EMBASE, CINAHL, BIOSIS, AMED, PubMed, PsycINFO, and registries of clinical trials. We also checked the references of all included studies and contacted authors of included studies for relevant studies and data. SELECTION CRITERIA: We included all randomised controlled trials comparing zuclopenthixol of any form with placebo for treatment of schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted and cross-checked data independently. We identified only a small number of studies so we cross checked all studies. We calculated fixed-effect relative risks (RR) and 95% confidence intervals (CI) for dichotomous data. We analysed by intention-to-treat. Where possible we converted continuous outcomes into dichotomous outcomes. When this was not possible we used mean differences (MD) for continuous variables. We assessed risk of bias for included studies and used GRADE (Grading of Recommendations Assessment, Development and Evaluation) to create a 'Summary of findings' table. MAIN RESULTS: Only two studies, with a total of 65 participants, were eligible for inclusion in the review. Overall the quality of the two studies was low, with small study populations and significant sources of bias, so we were not able to use all the data in our comparisons. . The studies were old from 1968 and 1972, and would be unlikely to pass modern peer review standard. We were only able to find short-term data and only trials randomising zuclopenthixol dihydrochloride. We also hoped to identify data for zuclopenthixol acetate versus placebo and zuclopenthixol decanoate versus placebo comparisons. We were unable to identify any studies that included data on these two fairly widely used drugs.For our primary outcome of interest, clinically significant improvement, we found one study that provided useable data. Global state measured by clinical global impression scale (CGI) improvement showed different ratings when assessed by a psychiatrist or a nurse.The psychiatrist scores failed to achieve statistical significance, however when assessed by nursing staff, the difference favouring zuclopenthixol did reach statistical significance (1 RCT n = 29, RR 2.57 95% CI 1.06 to 6.20, very low quality data). There was also evidence of increased sedation with those treated with zuclopenthixol when compared with placebo (1 RCT n = 29, RR 4.67 95% CI 1.23 to 17.68, very low quality data). 'Leaving the study early' data were equivocal. No useable data were available for outcomes such as relapse, mental state, death, quality of life, service use or economic costs. AUTHORS' CONCLUSIONS: For people with schizophrenia this review shows that zuclopenthixol dihydrochloride may help with the symptoms of schizophrenia. The review provides some trial evidence that, if taking zuclopenthixol dihydrochloride, people may experience some adverse effects and sedation compared with placebo. However this evidence is of very low quality and with some significant sources of bias. There are no data for zuclopenthixol decanoate or zuclopenthixol acetate.For clinicians, the available trial data on the absolute effectiveness of zuclopenthixol dihydrochloride do support its use but the limited nature of the data and significant sources of bias make conclusions hard to draw. Zuclopenthixol in all three forms is a commonly used antipsychotic and it is disappointing that there are so few data regarding its use.

Possible interaction between letrozole and long-acting injectable zuclopenthixol.

Mrs A, a 68-year-old woman with paranoid schizophrenia, was on long-term psychiatric treatment with long-acting intramuscular zuclopenthixol, quetiapine and alprazolam when, in April 2012, she was diagnosed with right breast infiltrating ductal carcinoma. After starting treatment with letrozole on 4 July, Mrs A progressively developed extrapyramidal symptoms and these were particularly evident after each zuclopenthixol administration. On 9 January, both quetiapine and alprazolam were stopped due to excessive lethargy. After the administration of the last dose of zuclopenthixol on 26 January, she presented with sedation, sialorrhea, festinant gait, axial dystonia and dysphagia, all of which were severe. The introduction of letrozole was the only change that had been made to her pharmacotherapeutic regimen in that period. The rest of the findings on neurological examination were normal. Renal function was adequate. Slow symptom onset and progressive worsening until full-blown clinical presentation after 6 months, and the dramatic improvement in the clinical picture achieved 2 days after treatment with biperiden, suggests a long-term insidious interaction leading to zuclopenthixol accumulation. To the best of our knowledge, this is the first report of a possible interaction between letrozole and zuclopenthixol. We consider that it warrants further investigation. In the meanwhile, physicians should be aware of the occurrence of this potentially serious drug-drug interaction.

Treatment of aggressive behavior problems in boys with intellectual disabilities using zuclopenthixol.

OBJECTIVE: Disruptive or challenging behavior problems pose a threat to children and adolescents with intellectual disabilities and their caregivers. Psychopharmacological treatment is mostly studied with new-generation antipsychotics and has been criticized for adverse side effects. This study examined the effect of the classic antipsychotic zuclopenthixol. METHODS: A total of 39 boys (ages 8.0-17.11 years) with learning disabilities were included and examined for a response to zuclopenthixol during a 6 week period of open label treatment. Doses started low and were adapted individually. From responders, zuclopenthixol was randomly withdrawn for 12 weeks. Responses to withdrawal were observed by external raters using the Modified Overt Aggression Scale. RESULTS: Of all patients included into the study, 15 were not randomized because of insufficient therapeutic effect, adverse event, or noncompliance. Kaplan-Meier estimations showed less aggressive behavior problems for the continuing subgroup (n=9) than in the placebo group (n=15). Individual doses stayed <10 mg/day. CONCLUSIONS: Zuclopenthixol proved to be effective in reducing challenging behavior in boys even at low doses.

Effects of zuclopenthixol on aggressive disruptive behavior in adults with mental retardation--a 2-year follow-up on a withdrawal study.

INTRODUCTION: People with mental retardation often display aggressive behavior against themselves or others making care within institutions or foster families difficult. Due to a lack of viable alternatives, antipsychotics of the first and second generations are often used for long-term treatment despite the fact that only data about short-term treatment exist. METHODS: A short-time withdrawal trial of 12 weeks (n = 39) was extended at open label to 2 years. 31 patients received zuclopenthixol after the end of the withdrawal and were examined using the same instruments as in the withdrawal period (DAS, MOAS, CGI). RESULTS: Patients still treated with zuclopenthixol after 2 years (n = 21) benefitted, compared to the drop-outs (n = 10). Analyses of time trends revealed an early effect of zuclopenthixol which could not be enhanced afterwards. DISCUSSION: Zuclopenthixol proved to be safe and effective to keep a lower rate of aggressive behavior in adults with mental retardation also over a longer period of time.

Neuroleptic malignant syndrome in adolescents: four probable cases in the Western Cape.

BACKGROUND: Neuroleptic malignant syndrome (NMS) is a rare side-effect of neuroleptic medication. Most NMS reports have been on adults, and the incidence in children and adolescents is unknown. OBJECTIVE: This report reviews cases of NMS to highlight possible risk factors for the development of NMS in adolescents. METHOD: Four cases of probable NMS in adolescents diagnosed in the Western Cape between February 2009 and March 2010 are presented. RESULTS: Risk factors in the development of the syndrome in adolescents in the Western Cape may be male gender, polypharmacy, the use of zuclopenthixol acetate (clopixol acuphase), a previous history of extra-pyramidal side-effects or NMS, and a history of substance misuse - in particular methamphetamine. CONCLUSION: Caution must be applied in the apparent overuse of intramuscular antipsychotics, and especially zuclopenthixol acetate (clopixol acuphase), in neuroleptic-naïve and agitated psychotic adolescents where the short-term use of benzodiazepines is more appropriate.

Stereotyped paroxysmal psychiatric symptoms during oculogyric crisis or 'cognitive dystonia': a case report.

Oculogyric crisis (OGC) is an acute dystonia which can occur after initiation of antipsychotic treatment. Stereotypic paroxysmal psychiatric symptoms have been described along with OGC that resolve spontaneously when the later remits. We report a case of tardive OGC associated with zuclopenthixol in which there were associated paroxysmal auditory pseudohallucinations.

An unusual presentation of cortical venous thrombosis and its association with typical antipsychotics.

A 41-year-old patient with schizophrenia was admitted to hospital following episodes of unexplained collapse attacks and on and off episodes of frontal headaches for 3 months. After three such episodes of loss of consciousness in 2 weeks duration and subsequent spontaneous recovery, his evaluation which included MRI scan of head revealed extensive cortical venous thrombosis. He was on zuclopenthixol (thioxanthene group) for several months for schizophrenia and was under regular psychiatric evaluation. He was treated for simple lower respiratory infection a week prior to admission. Other causes for any clotting disorders including vasculitic and thrombophilic screen were negative. There was no evidence of focal neurology on examination. Systemic examination was otherwise unremarkable. He was treated initially with unfractionated heparin and subsequently changed to warfarin with target international normalised ratio between two and three for at least 6 months and psychiatrist was advised to stop zuclopenthixol.

Prescription persistence and safety of antipsychotic medication: a national registry-based 3-year follow-up.

PURPOSE: Long-term persistence of use, lack of co-prescribed anticholinergic antiparkinson drugs and low mortality may indicate effectiveness and safety of antipsychotic drugs. We aimed to assess 3-year prescription persistence, concomitant use of anticholinergics and mortality related to the use of all antipsychotic agents available in Norway. METHODS: Data were drawn from the Norwegian Prescription Database on the sales of antipsychotic and anticholinergic antiparkinson agents in 2004 to a total of 52,427 patients. The primary study group was a subgroup of 34,494 patients who were prescribed only one antipsychotic agent in 2004. The patients were re-investigated in 2007. For each of the 13 antipsychotic agents studied, assumed prescription persistence was assessed in light of use of anticholinergic antiparkinson agents in 2004, and casualty rates were noted. RESULTS: The highest persistence was demonstrated for zuclopenthixol (69.8%) and clozapine (88.4%). Zuclopenthixol was often co-prescribed with anticholinergics (22.2%), in contrast to clozapine (3.6%). Ziprasidone was associated with a low mortality (OR = 0.08), while chlorprotixene and haloperidol were associated with a high mortality (OR = 1.34 and 3.97, respectively) compared to levomepromazine. CONCLUSIONS: Clozapine demonstrated a high degree of continuity of prescription and a low level of concomitant use of anticholinergics. Zuclopenthixol also demonstrated a high degree of continuity of prescription, despite a considerable degree of co-prescribed anticholinergics. We did not find that any antipsychotic other than ziprasidone was associated with a low mortality. The use of haloperidol seemed to confer a mortality risk three times that of any of the other antipsychotic agents included.

Severe laryngeal dystonia in a patient receiving zuclopenthixol "Acuphase" and fluoxetine.

OBJECTIVE: Prescribers are warned to be vigilant for potential cytochrome P450 mediated drug interactions; guidelines separately highlight risks of toxicity associated with zuclopenthixol acuphase. We previously examined potential cytochrome P450 interactions with zuclopenthixol and here describe dangerous side effects in a patient receiving zuclopenthixol acuphase and the selective serotonin reuptake inhibitor fluoxetine at high dose. METHOD: We present the case of a patient established on fluoxetine 80 mg/day who subsequently received injected zuclopenthixol acuphase 100 mg. RESULTS: Following zuclopenthixol acuphase administration, dangerous extra-pyramidal side effects were observed, including severe laryngeal dystonia necessitating emergency medical treatment. CONCLUSIONS: Our observations of symptoms of zuclopenthixol toxicity are consistent with a cytochrome P450 2D6/3A4 interaction with fluoxetine. Previous evidence demonstrating this interaction included only patients taking fluoxetine up to 60 mg/day. This case extends the evidence base. In patients taking high dose fluoxetine, we advise marked reductions in the prescribed dose of zuclopenthixol acuphase.

Metabolic syndrome with different antipsychotics: a multicentre cross-sectional study.

OBJECTIVE: High prevalence of metabolic syndrome (MS) and related metabolic disturbances in patients with schizophrenia and bipolar affective disorder have been in main focus of interest in recent years since the introduction of second-generation antipsychotics. This study aims to examine these questions: 1) Is there a relation between antipsychotic treatment and MS prevalence? 2) Which antipsychotic users have higher MS prevalence? 3) Do patients on antipsychotic polytherapy have higher rates of MS than patients on antipsychotic monotherapy? 4) Which metabolic parameters are considerably disturbed on which antipsychotic users? METHODS: 242 Patients with schizophrenia, schizoaffective disorder and bipolar disorder without any other psychiatric comorbidity according to DSM-IV and using the same antipsychotic(s) and/or mood stabilizers at least for the last 6 months included to the final assessment. RESULTS: The sample was divided into 7 drug groups. The MS prevalence was highest in the combined antipsychotic (AA) group (48.1%) according to ATP III criteria. According to IDF criteria clozapine (C) group had the highest MS prevalence (74%). CONCLUSIONS: When metabolic parameters evaluated overall, metabolic risk with antipsychotics is found to be highest in clozapine group, followed by combined AP group. Olanzapine and risperidone have intermediate risk while zuclopentixole has lowest.