Bioequivalency of generic and brand-named chlorpromazine

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.

Switching from brand-name to generic psychotropic medications: a literature review

Generic medications do not undergo the rigorous approval process required of original medications. Their effectiveness and safety is expected to be equal to that of their more expensive counterparts. However, several case reports and studies describe clinical deterioration and decreased tolerability with generic substitution. Pubmed was searched from January 1, 1974 to March 1, 2010. The MeSH term "generic, drugs" was combined with "anticonvulsants," "mood stabilizers," "lithium," "antidepressants," "antipsychotics," "anxiolytics," and "benzodiazepines." Additional articles were obtained by searching the bibliographies of relevant references. Articles in English, French, or Spanish were considered if they discussed clinical equivalence of generic and brand-name medications, generic substitution, or issues about effectiveness, tolerability, compliance, or economics encountered with generics. Clinical deterioration, adverse effects, and changes in pharmacokinetics are described with generic substitution of several anticonvulsants/mood stabilizers (carbamazepine, valproate, lamotrigine, gabapentin, topiramate, lithium), antidepressants (amitriptyline, nortriptyline, desipramine, fluoxetine, paroxetine, citalopram, sertraline, venlafaxine, mirtazapine, bupropion), antipsychotics (risperidone, clozapine), and anxiolytics (clonazepam, alprazolam). Generics do not always lead to the anticipated monetary savings and also raise compliance issues. Although the review is limited by publication bias and heterogeneity of the studies in the literature, we believe there is enough concern to advise generic switching on an individual basis with close monitoring throughout the transition. Health professionals should be aware of the stakes around generic substitution especially when health economics promote universal use of generics.

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.