Haloperidol and chlorpromazine: a double-blind cross-over trial and clinical study in children and adolescents

Chlorpromazine versus placebo for schizophrenia

BACKGROUND

Chlorpromazine, formulated in the 1950s, remains a benchmark treatment for people with schizophrenia.

OBJECTIVES

To review the effects of chlorpromazine compared with placebo, for the treatment of schizophrenia.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Trials Register (15 May 2012). We also searched references of all identified studies for further trial citations. We contacted pharmaceutical companies and authors of trials for additional information.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing chlorpromazine with placebo for people with schizophrenia and non-affective serious/chronic mental illness irrespective of mode of diagnosis. Primary outcomes of interest were death, violent behaviours, overall improvement, relapse and satisfaction with care.

DATA COLLECTION AND ANALYSIS

We independently inspected citations and abstracts, ordered papers, re-inspected and quality assessed these. We analysed dichotomous data using risk ratio (RR) and estimated the 95% confidence interval (CI) around this. We excluded continuous data if more than 50% of participants were lost to follow-up. Where continuous data were included, we analysed this data using mean difference (MD) with a 95% confidence interval. We used a fixed-effect model.

MAIN RESULTS

We inspected over 1100 electronic records. The review currently includes 315 excluded studies and 55 included studies. The quality of the evidence is very low. We found chlorpromazine reduced the number of participants experiencing a relapse compared with placebo during six months to two years follow-up (n = 512, 3 RCTs, RR 0.65 CI 0.47 to 0.90), but data were heterogeneous. No difference was found in relapse rates in the short, medium or long term over two years, although data were also heterogeneous. We found chlorpromazine provided a global improvement in a person's symptoms and functioning (n = 1164, 14 RCTs, RR 0.71 CI 0.58 to 0.86). Fewer people allocated to chlorpromazine left trials early ( n = 1831, 27 RCTs, RR 0.64 CI 0.53 to 0.78) compared with placebo. There are many adverse effects. Chlorpromazine is clearly sedating (n = 1627, 23 RCTs, RR 2.79 CI 2.25 to 3.45), it increases a person's chances of experiencing acute movement disorders (n = 942, 5 RCTs, RR 3.47 CI 1.50 to 8.03) and parkinsonism (n = 1468, 15 RCTs, RR 2.11 CI 1.59 to 2.80). Akathisia did not occur more often in the chlorpromazine group than placebo. Chlorpromazine clearly causes a lowering of blood pressure with accompanying dizziness (n = 1488, 18 RCTs, RR 2.38 CI 1.74 to 3.25) and considerable weight gain (n = 165, 5 RCTs, RR 4.92 CI 2.32 to 10.43).

AUTHORS' CONCLUSIONS

The results of this review confirm much that clinicians and recipients of care already know but aim to provide quantification to support clinical impression. Chlorpromazine's global position as a 'benchmark' treatment for psychoses is not threatened by the findings of this review. Chlorpromazine, in common use for half a century, is a well-established but imperfect treatment. Judicious use of this best available evidence should lead to improved evidence-based decision making by clinicians, carers and patients.

Haloperidol versus chlorpromazine for schizophrenia

BACKGROUND

Chlorpromazine and haloperidol are benchmark antipsychotic drugs. Both are said to be equally effective when used at equivalent doses, but have different side-effect profiles.

OBJECTIVES

To compare the effects of haloperidol and chlorpromazine for people with schizophrenia and schizophrenia-like psychoses.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group's register (August 2006). We searched references of all included studies for further trials. We contacted pharmaceutical companies and authors of relevant trials.

SELECTION CRITERIA

We included all randomised controlled trials that compared haloperidol with chlorpromazine for people with schizophrenia and/or schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

Citations and, where possible, abstracts were independently inspected by at least two reviewers, papers ordered, re-inspected and quality assessed. We independently extracted data. For dichotomous data we calculated the relative risk (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) on an intention-to-treat basis using a random-effects model. For continuous data, we calculated weighted mean differences (WMD).

MAIN RESULTS

We found 14 relevant studies, mostly of short duration, poorly reported and conducted in the 1970s (total n=794 participants). Nine of these compared oral formulations of both compounds, and five compared intramuscular formulations. Haloperidol was associated with significantly fewer people leaving the studies early (13 RCTs, n=476, RR 0.26 CI 0.08 to 0.82). The efficacy outcome 'no significant improvement' tended to favour haloperidol, but this difference was not statistically significant (9 RCTs, n=400, RR 0.81 CI 0.64 to 1.04). Movement disorders were more frequent in the haloperidol groups ('at least one extrapyramidal side effect': 6 RCTs, n=37, RR 2.2 CI 1.1 to 4.4, NNH 5 CI 3 to 33), while chlorpromazine was associated with more frequent hypotension (5 RCTs, n=175, RR 0.31 CI 0.11 to 0.88, NNH 7 CI 4 to 25). Similar trends were found when studies comparing intramuscular formulations and studies comparing oral formulations were analysed separately.

AUTHORS' CONCLUSIONS

Given that haloperidol and chlorpromazine are global standard antipsychotic treatments for schizophrenia, it is surprising that less than 800 people have been randomised to a comparison and that incomplete reporting still makes it difficult for anyone to draw clear conclusions on the comparative effects of these drugs. However, it seems that haloperidol causes more movement disorders than chlorpromazine, while chlorpromazine is significantly more likely to lead to hypotonia. We are surprised to have to say that we feel further, large, well designed, conducted and reported studies are required.

Antipsychotic medication for childhood-onset schizophrenia

BACKGROUND

Childhood-onset schizophrenia is schizophrenia with onset prior to the age of 13 years. Although it is rare, people who suffer from schizophrenia at an early age appear to have a clinically severe form of the illness with poor long-term prognosis. Antipsychotic medication is one way of managing this rare but serious mental illness.

OBJECTIVES

To examine the effects of antipsychotic medication for childhood-onset schizophrenia.

SEARCH STRATEGY

We searched the Cochrane Schizophrenia Group Trials Register (November 2006 and February 2007), inspected references of all identified studies for further trials and contacted relevant pharmaceutical companies and authors of trials for additional information.

SELECTION CRITERIA

We included all randomised clinical trials involving children and young people with a diagnosis of childhood onset schizophrenia (i.e. with a diagnosis of schizophrenia before the age of 13) comparing any antipsychotic drug with another antipsychotic or placebo.

DATA COLLECTION AND ANALYSIS

We reliably selected, quality assessed and extracted data from trials. We excluded data where more than 50% of participants in any group were lost to follow up. For homogenous dichotomous data we calculated random effects, relative risk (RR) and its 95% confidence interval (CI) and, where appropriate, number needed to treat (NNT) on an intention-to-treat basis. For normal continuous data we calculated the weighted mean difference (WMD).

MAIN RESULTS

From a total of 2062 citations, we identified six relevant trials. We categorised trials into three comparisons: atypical versus typical, atypical versus atypical and typical versus typical antipsychotic drugs. The only comparison to find any differences between treatment groups was atypical versus typical antipsychotic drugs. A few results from one study favoured the atypical antipsychotic clozapine over haloperidol in treating treatment resistant childhood-onset schizophrenia (n=21, WMD CGAS 17.00 CI 7.74 to 26.26; n=21, WMD Bunney-Hamburg Psychosis Rating Scale -3.60 CI -6.64 to -0.56). Participants on clozapine, however, were three times more likely to have drowsiness (1 RCT, n=21, RR 3.30 CI 1.23 to 8.85, NNH 2 CI 2 to 17) and half of the children receiving clozapine had neutropenia (1 RCT, n=21, RR 12, CI 0.75 to 192.86).

AUTHORS' CONCLUSIONS

There are few relevant trials and, presently, there is little conclusive evidence regarding the effects of antipsychotic medication for those with early onset schizophrenia. Some benefits were identified in using the atypical antipsychotic clozapine compared with haloperidol but the benefits were offset by an increased risk of serious adverse effects. Larger, more robust, trials are required.

Chlorpromazine versus placebo for schizophrenia

BACKGROUND

Chlorpromazine, formulated in the 1950s, remains a benchmark treatment for people with schizophrenia.

OBJECTIVES

To evaluate the effects of chlorpromazine for schizophrenia in comparison with placebo.

SEARCH STRATEGY

We updated previous searches of the Cochrane Schizophrenia Group Register (October 1999), Biological Abstracts (1982-1995), the Cochrane Library (1999, Issue 2), EMBASE (1980-1995), MEDLINE (1966-1995), PsycLIT (1974-1995), and the Cochrane Schizophrenia Group Register (June 2002), by searching The Cochrane Schizophrenia Group Trials Register (January 2007). We searched references of all identified studies for further trial citations. We contacted pharmaceutical companies and authors of trials for additional information.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) comparing chlorpromazine with placebo for people with schizophrenia and non-affective serious/chronic mental illness irrespective of mode of diagnosis. Primary outcomes of interest were death, violent behaviours, overall improvement, relapse and satisfaction with care.

DATA COLLECTION AND ANALYSIS

We independently inspected citations and abstracts, ordered papers, re-inspected and quality assessed these. BT and JR extracted data. CEA and GA independently checked a 10% sample for reliability. We analysed dichotomous data using fixed effects relative risk (RR) and estimated the 95% confidence interval (CI) around this. Where possible we calculated the number needed to treat (NNT) or number needed to harm (NNH) statistics. We excluded continuous data if more than 50% of participants were lost to follow up; where continuous data were included, we analysed this data using fixed effects weighted mean difference (WMD) with a 95% confidence interval.

MAIN RESULTS

We inspected over 1000 electronic records. The review currently includes 302 excluded studies and 50 included studies. We found chlorpromazine reduces relapse over the short (n=74, 2 RCTs, RR 0.29 CI 0.1 to 0.8) and medium term (n=809, 4 RCTs, RR 0.49 CI 0.4 to 0.6) but data are heterogeneous. Longer term homogeneous data also favoured chlorpromazine (n=512, 3 RCTs, RR 0.57 CI 0.5 to 0.7, NNT 4 CI 3 to 5). We found chlorpromazine provided a global improvement in a person's symptoms and functioning (n=1121, 13 RCTs, RR 'no change/not improved' 0.80 CI 0.8 to 0.9, NNT 6 CI 5 to 8). Fewer people allocated to chlorpromazine left trials early (n=1780, 26 RCTs, RR 0.65 CI 0.5 to 0.8, NNT 15 CI 11 to 24) compared with placebo. There are many adverse effects. Chlorpromazine is clearly sedating (n=1404, 19 RCTs, RR 2.63 CI 2.1 to 3.3, NNH 5 CI 4 to 8), it increases a person's chances of experiencing acute movement disorders (n=942, 5 RCTs, RR 3.5 CI 1.5 to 8.0, NNH 32 CI 11 to 154), parkinsonism (n=1265, 12 RCTs, RR 2.01 CI 1.5 to 2.7, NNH 14 CI 9 to 28). Akathisia did not occur more often in the chlorpromazine group than placebo (n=1164, 9 RCTs, RR 0.78 CI 0.5 to 1.1). Chlorpromazine clearly causes a lowering of blood pressure with accompanying dizziness (n=1394, 16 RCTs, RR 2.37 CI 1.7 to 3.2, NNH 11 CI 7 to 21) and considerable weight gain (n=165, 5 RCTs, RR 4.92 CI 2.3 to 10.4, NNH 2 CI 2 to 3).

AUTHORS' CONCLUSIONS

The results of this review confirm much that clinicians and recipients of care already know but aim to provide quantification to support clinical impression. Chlorpromazine's global position as a 'benchmark' treatment for psychoses is not threatened by the findings of this review. Chlorpromazine, in common use for half a century, is a well established but imperfect treatment. Judicious use of this best available evidence should lead to improved evidence-based decision making by clinicians, carers and patients.

Chlorpromazine versus placebo for schizophrenia

BACKGROUND

Chlorpromazine, formulated in the 1950s, remains a benchmark treatment for people with schizophrenia.

OBJECTIVES

To evaluate the effects of chlorpromazine for schizophrenia in comparison with placebo.

SEARCH STRATEGY

We updated previous searches of the Cochrane Schizophrenia Group Register (October 1999), Biological Abstracts (1982-1995), the Cochrane Library (1999, Issue 2), EMBASE (1980-1995), MEDLINE (1966-1995) and PsycLIT (1974-1995), by searching Cochrane Schizophrenia Group Register (June 2002). References of all identified studies were searched for further trial citations. Pharmaceutical companies and authors of trials were contacted.

SELECTION CRITERIA

All randomised controlled trials (RCTs) comparing chlorpromazine with placebo relevant to people with schizophrenia, and non-affective serious/chronic mental illness irrespective of mode of diagnosis. Primary outcomes of interest were death, violent behaviours, overall improvement, relapse and satisfaction with care.

DATA COLLECTION AND ANALYSIS

Citations and, where possible, abstracts were inspected independently by reviewers, papers ordered, re-inspected and quality assessed. Data were extracted by BT and JR. CA and GA independently checked a 10% sample for reliability. Dichotomous data were analysed using random effects relative risk (RR) and the 95% confidence interval (CI) around this was estimated. Where possible the number needed to treat (NNT) or number needed to harm statistics (NNH) were calculated. Continuous data were excluded if more than 50% of people were lost to follow up, but, where possible, weighted mean difference (WMD) was calculated.

MAIN RESULTS

Over 1000 electronic records were inspected. The review currently mentions 302 papers in its Excluded Studies table and 50 studies in its Included Studies table. Four papers are awaiting translation. Chlorpromazine reduces relapse over six months to two years (n=512, 3 RCTs, RR 0.65 CI 0.5 to 0.9, NNT 3 CI 2.5 to 4) and promotes a global improvement in a person's symptoms and functioning (n=1121, 13 RCTs, RR 0.76 CI 0.7 to 0.9, NNT 7 CI 5 to 10) although the placebo response is also considerable. Fewer people allocated to chlorpromazine leave trials early (n=1755, 25 RCTs, RR 0.77 CI 0.6 to 1.1) but the difference iss not statistically significant. There are many adverse effects. Chlorpromazine is clearly sedating (n=1242, 18 RCTs, RR 2.3 CI 1.7 to 3.1, NNH 6 CI 5 to 8), it increases a person's chances of experiencing acute movement disorders (n=780, 4 RCTs, RR 3.1 CI 1.3 to 7.7, NNH 24 CI 15 to 57), parkinsonism (n=1265, 12 RCTs, RR 2.6 CI 1.2 to 5.4, NNH 10 CI 8 to 16) and, perhaps, fits (n=695, 3 RCTs, RR 2.4 CI 0.4 to 16). Amongst other things it clearly causes a lowering of blood pressure with accompanying dizziness (n=1232, 15 RCTs, RR 1.9 CI 1.4 to 27, NNH 12 CI 8 to 19) and considerable increases in weight (n=165, 5 RCTs, RR 4.4 CI 2.1 to 9, NNH 3 CI 2 to 5).

REVIEWER'S CONCLUSIONS

This review will confirm much that clinicians and recipients of care already know, but provides quantification to support clinical impression. Chlorpromazine's global position as a 'benchmark' treatment for psychoses is not threatened by this review. Chlorpromazine, in common use for half a century, is a well established but imperfect treatment. Judicious use of this best available evidence should lead to improved evidence-based decision making by clinicians, carers and patients.