Loxapine versus thioridazine in the treatment of organic psychosis

Loxapine for schizophrenia

BACKGROUND

Some authors have suggested that loxapine is more effective than typical antipsychotics in reducing the negative symptoms of schizophrenia, that extrapyramidal adverse effects are not usually seen at clinically effective antipsychotic doses and that it should therefore be classed as atypical.

OBJECTIVES

To determine the effects of loxapine compared with placebo, typical and other atypical antipsychotic drugs for schizophrenia and related psychoses.

SEARCH STRATEGY

For this 2007 update, we searched the Cochrane Schizophrenia Group's Register (January 2007).

SELECTION CRITERIA

We included all randomised controlled clinical trials relevant to the care of schizophrenia that compared loxapine to other treatments.

DATA COLLECTION AND ANALYSIS

We independently inspected abstracts ordered papers, re-inspected and quality assessed these. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a fixed effects 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 effects model.

MAIN RESULTS

We were able to include 41 studies in this review. Compared with placebo, loxapine has an antipsychotic effect (Global effect - not improved at six weeks: n=78, 2 RCTs, RR 0.30 CI 0.1 to 0.6 NNT 3 CI 3 to 5). It is as effective as typical drugs in the short term (4 -12 weeks) (Global effect: n=580, 13 RCTs, RR 0.86 CI 0.7 to 1.1; mental state: n=915, 6 RCTs, RR 0.89 CI 0.8 to 1.1). Very limited heterogeneous data suggest that, given intramuscularly (IM), loxapine may be at least as sedating as IM haloperidol and thiothixene. Loxapine is also as effective as atypicals (risperidone, quetiapine) (n=468, 6 RCTs, RR mental state not improved 1.07 CI 0.8 to 1.5). Adverse effect profile is similar to typicals but loxapine may cause more extrapyramidal adverse effects when compared with atypicals (n=340, 4 RCTs, RR 2.18 CI 1.6 to 3.1).

AUTHORS' CONCLUSIONS

Loxapine is an antipsychotic which is not clearly distinct from typical or atypical drugs in terms of its effects on global or mental state. Loxapines profile of adverse effects is similar to that of the older generation of antipsychotic drugs.

Thioridazine for schizophrenia

BACKGROUND

Thioridazine is an antipsychotic that can still be used for schizophrenia although it is associated with the cardiac arrhythmia, torsades de pointe.

OBJECTIVES

To review the effects of thioridazine for people with schizophrenia.

SEARCH STRATEGY

For this 2006 update, we searched the Cochrane Schizophrenia Group's Register (June 2006).

SELECTION CRITERIA

We included all randomised clinical trials comparing thioridazine with other treatments for people with schizophrenia or other psychoses.

DATA COLLECTION AND ANALYSIS

We reliably selected, quality rated and extracted data from relevant studies. For dichotomous data, we estimated relative risks (RR), with the 95% confidence intervals (CI). Where possible, we calculated the number needed to treat/harm statistic (NNT/H) on an intention-to-treat basis.

MAIN RESULTS

This review currently includes 42 RCTs with 3498 participants. When thioridazine was compared with placebo (total n=668, 14 RCTs) we found global state outcomes favoured thioridazine (n=105, 3 RCTs, RR 'no change or worse' by 6 months 0.33 CI 0.2 to 0.5, NNT of 2 CI 2 to 3). Thioridazine is sedating (n=324, 3 RCTs, RR 5.37 CI 3.2 to 9.1, NNH 4 CI 2 to 74). Generally, thioridazine did not cause more movement disorders than placebo.Twenty-seven studies (total n=2598) compared thioridazine with typical antipsychotics. We found no significant difference in global state (n=743, 11 RCTs, RR no short-term change or worse 0.98 CI 0.8 to 1.2) and medium-term assessments (n=142, 3 RCTs, RR 0.99, CI 0.6 to 1.6). We found no significant differences in the number of people leaving the study early 'for any reason' (short-term, n=1587, 19 RCTs, RR 1.07 CI 0.9 to 1.3). Extrapyramidal adverse events lower for those allocated to thioridazine (n=1082, 7 RCTs, RR use of antiparkinsonian drugs 0.45 CI 0.4 to 0.6). Thioridazine did seem associated with cardiac adverse effects (n=74, 1 RCT, RR 'any cardiovascular adverse event' 3.17 CI 1.4 to 7.0, NNH 3 CI 2 to 5). Electrocardiogram changes were significantly more frequent in the thioridazine group (n=254, 2 RCTs, RR 2.38, CI 1.6 to 3.6, NNH 4 CI 3 to 10). Six RCTs (total n=344) randomised thioridazine against atypical antipsychotics. Global state rating did not reveal any short-term difference between thioridazine and remoxipride and sulpiride (n=203, RR not improved or worse 1.00 CI 0.8 to 1.3). Limited data did not highlight differences in adverse event profiles.

AUTHORS' CONCLUSIONS

Although there are shortcomings, there appears to be enough consistency over different outcomes and periods to confirm that thioridazine is an antipsychotic of similar efficacy to other commonly used antipsychotics for people with schizophrenia. Its adverse events profile is similar to that of other drugs, but it may have a lower level of extrapyramidal problems and higher level of ECG changes. We would advocate the use of alternative drugs, but if its use in unavoidable, cardiac monitoring is justified.

Antipsychotic medication versus placebo for people with both schizophrenia and learning disability

BACKGROUND

Antipsychotic medication is the standard treatment for people with learning disability and schizophrenia.

OBJECTIVES

To determine the effects of any antipsychotic medication compared with placebo for treating people with a dual diagnosis of learning disability and schizophrenia.

SEARCH STRATEGY

For this update we searched the Cochrane Schizophrenia Group's Register of trials (July 2004), relevant reference lists and sought unpublished data from pharmaceutical companies.

SELECTION CRITERIA

We included all randomised clinical trials of longer than one month's duration, involving people with both schizophrenia and learning disability (a measured IQ of 70 or less) that evaluated antipsychotic medication versus placebo.

DATA COLLECTION AND ANALYSIS

We reliably selected and assessed studies for methodological quality. Two reviewers, working independently, extracted data. We would have analysed dichotomous data on an intention-to-treat basis and presented continuous data with 65% completion rate. For dichotomous outcomes, our intention was to estimate a fixed effect relative risk (RR) with the 95% confidence interval (CI) together with the number needed to treat/harm (NNT/H).

MAIN RESULTS

We found only one relevant randomised trial using our search method and this had to be excluded. This study included four people with a dual diagnosis of schizophrenia and learning disability, but results were only available for two of the participants. It was unclear as to which groups the other two people were allocated. In order to display the data, we would have had to have made too many assumptions about these two people and any results would be uninformative and potentially misleading.

REVIEWERS' CONCLUSIONS

Using the methods described we found no randomised controlled trial evidence to guide the use of antipsychotic medication for people with both learning disability and schizophrenia. Until the urgent need for randomised controlled trials is met, clinical practice will continue to be guided by extrapolation of evidence from randomised controlled trials involving people with schizophrenia, but without learning disability, and non-randomised trials of those with learning disability and schizophrenia.

Loxapine for schizophrenia

BACKGROUND

Loxapine is a drug with D2/D3 receptor antagonist activity and a higher affinity for D3 than D2. Some authors have suggested that loxapine is more effective than typical antipsychotics in reducing the negative symptoms of schizophrenia, that extrapyramidal side-effects are not usually seen at clinically effective antipsychotic doses and that it should therefore be classed as atypical.

OBJECTIVES

To determine the effects of loxapine compared with placebo, typical and other atypical antipsychotic drugs for schizophrenia and related psychoses.

SEARCH STRATEGY

Electronic searches of Biological Abstracts (1980-1999), The Cochrane Library (Issue 1, 1999), The Cochrane Schizophrenia Group's Register (January 1999), EMBASE (1980-1999), MEDLINE (1966-1999), LILACS (1982-1996), PSYNDEX (1977-1995) and PsycLIT (1974-1999) were undertaken. In addition, pharmaceutical databases on the Dialog Corporation Datastar and Dialog services were searched. References of all identified studies were searched for further trials. Pharmaceutical companies and authors of trials were contacted.

SELECTION CRITERIA

All randomised controlled clinical trials relevant to the care of schizophrenia that compared loxapine to other treatments.

DATA COLLECTION AND ANALYSIS

Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were independently extracted but excluded if loss to follow up was greater than 50%. For homogeneous dichotomous data the risk ratio (RR), 95% confidence interval (CI) and, where appropriate, the number needed to treat (NNT) were calculated on an intention-to-treat basis. For continuous data, weighted mean differences were calculated (WMD). All data were inspected for heterogeneity.

MAIN RESULTS

Compared to placebo, loxapine is antipsychotic (Global effect - not improved at 6 weeks, n=66, RR 0.6 CI 0.4-0.9 NNT 4 CI 2-62) with similar adverse effect profile to typical drugs. Is as effective as typical drugs in the short term (4-12 weeks) (Global effect - not improved, n=411, RR 0.89 CI 0.7-1.2). Very limited heterogeneous data suggest that, given intramuscularly (IM), loxapine may be at least as sedating as IM haloperidol and thiothixene.

REVIEWER'S CONCLUSIONS

Loxapine is antipsychotic but its effects are under researched. It is not clearly different from typical drugs in either its positive or adverse effects.

Antipsychotic medication for those with both schizophrenia and learning disability

BACKGROUND

Antipsychotic medication is the standard treatment for people with learning disability and schizophrenia.

OBJECTIVES

To determine the efficacy of any antipsychotic medication for treating people with a dual diagnosis of learning disability and schizophrenia.

SEARCH STRATEGY

Electronic searching of Biological Abstracts, the Cochrane Schizophrenia Group's Register of trials, the Cochrane Library, EMBASE, PsycLIT and MEDLINE. Unpublished data were sought from pharmaceutical companies. Both authors independently selected the relevant studies from the reports identified in this way.

SELECTION CRITERIA

1. All randomised controlled trials of antipsychotic medication, regardless of dosage, versus a placebo control, of longer than one month's duration. 2. Anyone over 18 years of age with both learning disability and schizophrenia. Learning disability was defined as a measured IQ of 70 or less. Any mode of diagnosis of schizophrenia was acceptable.

DATA COLLECTION AND ANALYSIS

The two reviewers independently attempted to select and then extract data but it was not possible to do this with the single study that met the inclusion criteria.

MAIN RESULTS

Only one relevant randomised trial was found by the searches. This study included four people with a dual diagnosis of schizophrenia and learning disability, but results were available for only two. The groups to which the other two people were allocated were unclear. In order to display the data, too many assumptions would have to have been made about these other two people and any results would be uninformative and potentially misleading.

REVIEWER'S CONCLUSIONS

Using the methods described the reviewers found no randomised controlled trial evidence to guide the use of antipsychotic medication for those with both learning disability and schizophrenia. Until the urgent need for randomised controlled trials is met clinical practice will continue to be guided by extrapolation of evidence from randomised controlled trials involving people with schizophrenia but without learning disability and non-randomised trials of those with learning disability and schizophrenia.

Thioridazine for dementia

BACKGROUND

Neuroleptic drugs are controversial treatments in dementia, with evidence accumulating that they may hasten clinical decline. Despite these concerns, they are commonly prescribed for elderly and demented patients. Thioridazine, a phenothiazine neuroleptic, is one of the most commonly prescribed. It has often been a preferred agent because it is thought to produce relatively less frequent motor side effects. The drug has significant sedative effects, and it is thought that these are the main mechanism of action in calming and controlling the patient. However, pharmacologically, it also has marked anticholinergic properties that could potentially have a detrimental effect on cognitive function.

OBJECTIVES

To determine the evidence on which the use of thioridazine in dementia is based in terms of: 1) efficacy in controlling symptoms 2) cognitive outcome for the patient 3) safety

SEARCH STRATEGY

The Cochrane Controlled Trials Register and other electronic databases were searched using the terms 'thioridazine', 'melleril', 'dementia' and 'old age'. In addition, Novartis, the pharmaceutical company that developed and markets thioridazine, was approached and asked to release any published or unpublished data they had on file.

SELECTION CRITERIA

Unconfounded, single-blind or double-blind, randomised trials were identified in which treatment with thioridazine was administered for more than one dose and compared to an alternative intervention in patients with dementia of any aetiology. Trials in which allocation to treatment or comparator were not truly random, or in which treatment allocation was not concealed were reviewed but are not included in the data analysis.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by the reviewers (VC, CAK and RJH). For continuous and ordinal variables, the main outcome measures of interest were the final assessment score and the change in score from baseline to the final assessment. The assessment scores were provided by behavioural rating scales, clinical global impression scales, functional assessment scales, psychometric test scores, and frequency and severity of adverse events. Data were pooled where appropriate or possible, and the Peto odds ratio (95%CI) or the weighted mean difference (95%CI) estimated. Where possible, intention to treat data were used.

MAIN RESULTS

The meta-analysis showed that, compared with placebo, thioridazine reduced anxiety symptoms as evidenced by changes on the Hamilton Anxiety Scale. However, there was no significant effect on clinical global change, and a non-significant trend for higher adverse effects with thioridazine. Compared to diazepam, thioridazine was superior in terms of some anxiety symptoms, with similar adverse effects. Global clinical evaluation scales mostly did not favour either treatment. Compared to chlormethiazole, thioridazine was significantly inferior when assessed on some items of the CAPE and the Crichton Geriatric Behavioural Rating Scales. Thioridazine was also associated with significantly more dizziness. No superiority for thioridazine was shown in comparisons with etoperidone, loxapine or zuclopenthixol.

REVIEWER'S CONCLUSIONS

Very limited data are available to support the use of thioridazine in the treatment of dementia. If thioridazine were not currently in widespread clinical use, there would be inadequate evidence to support its introduction. The only positive effect of thioridazine when compared to placebo is the reduction of anxiety. When compared to placebo, other neuroleptics, and other sedatives it has equal or higher rates of adverse effects. Clinicians should be aware that there is no evidence to support the use of thioridazine in dementia, and its use may expose patients to excess side effects.

Effectiveness of antipsychotic medication in people with intellectual disability and schizophrenia: a systematic review

The aim of the present study was to determine the efficacy of any antipsychotic medication for treating people with a dual diagnosis of intellectual disability and schizophrenia. The authors performed an electronic search of Biological Abstracts, the Cochrane Schizophrenia Group's Register of trials, the Cochrane Library, EMBASE, PsycLIT and MEDLINE. Unpublished data were sought from pharmaceutical companies. Both authors independently selected the relevant studies from the reports identified in this way. Only one relevant randomized trial was found by the searches (Foote 1958). This study included four people with a dual diagnosis of schizophrenia and intellectual disability, but results were only available for two subjects. The groups to which the other two people were allocated were unclear. Using the methods described, the reviewers found no trial evidence to guide the use of antipsychotic medication for those with both intellectual disability and schizophrenia. Until the urgent need for randomized controlled trials is met, clinical practice will continue to be guided by evidence from trials involving people with schizophrenia but without intellectual disability.