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Cochrane Database of Systematic Reviews

Zuclopenthixol versus placebo for schizophrenia

Overview of attention for article published in Cochrane database of systematic reviews, December 2015
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  • In the top 25% of all research outputs scored by Altmetric
  • High Attention Score compared to outputs of the same age (83rd percentile)
  • Average Attention Score compared to outputs of the same age and source

Mentioned by

15 tweeters
1 Facebook page


2 Dimensions

Readers on

160 Mendeley
Zuclopenthixol versus placebo for schizophrenia
Published in
Cochrane database of systematic reviews, December 2015
DOI 10.1002/14651858.cd010598.pub2
Pubmed ID

Michael Lacey, Mahesh B Jayaram


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. To evaluate the effectiveness of all formulations of zuclopenthixol when compared with a placebo in schizophrenia. 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. We included all randomised controlled trials comparing zuclopenthixol of any form with placebo for treatment of schizophrenia or schizophrenia-like psychoses. 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. 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. 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.

Twitter Demographics

The data shown below were collected from the profiles of 15 tweeters who shared this research output. Click here to find out more about how the information was compiled.

Mendeley readers

The data shown below were compiled from readership statistics for 160 Mendeley readers of this research output. Click here to see the associated Mendeley record.

Geographical breakdown

Country Count As %
Spain 1 <1%
Unknown 159 99%

Demographic breakdown

Readers by professional status Count As %
Student > Master 30 19%
Student > Bachelor 21 13%
Student > Ph. D. Student 17 11%
Researcher 12 8%
Student > Doctoral Student 10 6%
Other 19 12%
Unknown 51 32%
Readers by discipline Count As %
Medicine and Dentistry 40 25%
Nursing and Health Professions 20 13%
Psychology 20 13%
Pharmacology, Toxicology and Pharmaceutical Science 6 4%
Computer Science 3 2%
Other 18 11%
Unknown 53 33%

Attention Score in Context

This research output has an Altmetric Attention Score of 9. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 29 April 2016.
All research outputs
of 16,187,495 outputs
Outputs from Cochrane database of systematic reviews
of 11,424 outputs
Outputs of similar age
of 369,420 outputs
Outputs of similar age from Cochrane database of systematic reviews
of 222 outputs
Altmetric has tracked 16,187,495 research outputs across all sources so far. Compared to these this one has done well and is in the 84th percentile: it's in the top 25% of all research outputs ever tracked by Altmetric.
So far Altmetric has tracked 11,424 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 24.0. This one has gotten more attention than average, scoring higher than 54% of its peers.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 369,420 tracked outputs that were published within six weeks on either side of this one in any source. This one has done well, scoring higher than 83% of its contemporaries.
We're also able to compare this research output to 222 others from the same source and published within six weeks on either side of this one. This one is in the 38th percentile – i.e., 38% of its contemporaries scored the same or lower than it.