Anticholinergic medication for neuroleptic-induced tardive dyskinesia (Review)

Anticholinergic medication for neuroleptic-induced tardive dyskinesia (Review) Soares-Weiser K, Mobsy C, Holliday E This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published in The Cochrane Library 2012, Issue 12 http://www.thecochranelibrary.com

T A B L E O F C O N T E N T S HEADER....................................... ABSTRACT...................................... PLAIN LANGUAGE SUMMARY.............................. BACKGROUND.................................... OBJECTIVES..................................... METHODS...................................... RESULTS....................................... DISCUSSION..................................... AUTHORS CONCLUSIONS............................... ACKNOWLEDGEMENTS................................ REFERENCES..................................... CHARACTERISTICS OF STUDIES............................. DATA AND ANALYSES.................................. ADDITIONAL TABLES.................................. FEEDBACK...................................... WHAT S NEW..................................... HISTORY....................................... CONTRIBUTIONS OF AUTHORS............................. DECLARATIONS OF INTEREST.............................. SOURCES OF SUPPORT................................. NOTES........................................ INDEX TERMS.................................... 1 1 2 2 3 3 5 6 6 7 7 9 15 15 15 16 16 16 17 17 17 17 i

[Intervention Review] Anticholinergic medication for neuroleptic-induced tardive dyskinesia Karla Soares-Weiser 1, Caroline Mobsy 2, Eleanor Holliday 3 1 Enhance Reviews Ltd, Wantage, UK. 2 West Hobart, Australia. 3 Nottingham, UK Contact address: Caroline Mobsy, 1/46 Summerhill Road, West Hobart, Tasmania, 7000, Australia. cmobsby@utas.edu.au. Editorial group: Cochrane Schizophrenia Group. Publication status and date: Edited (no change to conclusions), published in Issue 12, 2012. Review content assessed as up-to-date: 1 June 2000. Citation: Soares-Weiser K, Mobsy C, Holliday E. Anticholinergic medication for neuroleptic-induced tardive dyskinesia. Cochrane Database of Systematic Reviews 1997, Issue 2. Art. No.: CD000204. DOI: 10.1002/14651858.CD000204. Background A B S T R A C T Neuroleptic medication is used extensively to treat people with chronic mental illnesses. However, it is associated with a wide range of adverse effects, including movement disorders. Because of this, many acutely psychotic patients being treated with neuroleptic medication also receive anticholinergic drugs in order to reduce some of the associated movement side-effects. Objectives To determine whether the use or the withdrawal of anticholinergic drugs (benzhexol or benztropine or biperiden or orphenadrine or procyclidine or scopolamine or trihexylphenidyl) were clinically effective for the treatment of people with both neuroleptic-induced TD and schizophrenia or other chronic mental illnesses. Search methods Electronic searches of Biological Abstracts (1982-2000), Cochrane Schizophrenia Group s Register of trials (2000), EMBASE (1980-2000), LILACS (1982-1996), MEDLINE (1966-2000), PsycLIT (1974-2000), and SCISEARCH (1995) were undertaken. References of all identified studies were searched for further trial citations. Principal authors of trials were contacted. We updated this search August 2012 and added eight new trials to the awaiting classification section. Selection criteria Reports identified in the search were included if they were controlled trials dealing with people with neuroleptic-induced TD and schizophrenia or other chronic mental illness who had been randomly allocated to either an anticholinergic agent or to a placebo (or no intervention). Data collection and analysis No data could be extracted from the seven randomised controlled trials identified. Main results No data were synthesized. The authors have been contacted to provide the relevant information. Two studies were excluded because no data are available and six others are still awaiting further information from the authors. 1

Authors conclusions Based on currently available information, no confident statement can be made about the effectiveness of anticholinergics to treat people with neuroleptic-induced tardive dyskinesia. The same applies for the withdrawal of such medications. Whether the withdrawal of anticholinergics may benefit people with neuroleptic-induced TD, this should be evaluated in a parallel-group, placebo-controlled randomised trial, with adequate sample size and at least 6 weeks of follow up. Note: the eight citations in the awaiting classification section of the review may alter the conclusions of the review once assessed. P L A I N L A N G U A G E S U M M A R Y Anticholinergic medication for neuroleptic-induced tardive dyskinesia Synopsis pending. B A C K G R O U N D Since the 1950s neuroleptic medication has been used extensively to treat people with chronic mental illnesses, such as schizophrenia. These drugs can effectively control symptoms such as abnormal perceptions (hallucinations), disordered thinking and fixed false beliefs (delusions). In addition, maintenance therapy with neuroleptics is associated with a reduced risk of relapses (Schooler 1993). However, neuroleptic medication has been also associated with a wide range of adverse effects, including movement disorders. The appearance of these movement disorders can contribute to poor compliance with neuroleptic treatment (Barnes 1993). Tardive dyskinesia (TD) is one such movement disorder and is characterised by abnormal, repetitive and involuntary movements. TD is a chronic condition of insidious onset, the severity of which spontaneously fluctuates (APA 1992). It occurs in over 20% of those using neuroleptic medication continually for longer than three months. Every year 4-5% of those who continually use these drugs begin to show signs of TD (APA 1992). This disorder can result in considerable social and physical disability (Barnes 1993). Although the most frequent cause of TD is the use of neuroleptic medication it is striking that dose reduction can lead to a temporary exacerbation in symptoms. Conversely, increasing the dose is often associated with a temporary remission. Neuroleptic drugs block certain chemical receptor sites in the brain - one of these is specific for dopamine (Casey 1994). One hypothesis explaining the cause of neuroleptic-induced TD is that chronic blockade of dopamine receptors in specific cells of the brain (neurones from the nigrostriatum) causes an overgrowth of these receptors (Casey 1994). Consequently, interactions between neuroleptic drugs and dopamine receptors in the brain have been proposed as both the mechanisms for their beneficial effects in psychoses as well as the cause of the movement disorder side effects, including TD (Jeste 1982). In addition, there is evidence to suggest that an imbalance between cells that use dopamine and cells that use a chemical called acetylcholine may be a cause of TD (Alphs 1983, Casey 1994). Drugs that reduce the activity of the cholinergic cells (anticholinergic drugs) are widely used to help treat other neuroleptic induced movement disorders such as parkinsonism and dystonia (APA 1992). Many acutely psychotic patients who receive neuroleptic medication also receive anticholinergic drugs in order to reduce some of the movement side-effects associated with neuroleptic medication. The rationale for their use in TD is less clear, as there is suggestion from animal experiments that the chronic administration of anticholinergics could increase the supersensitivity of dopamine receptors and consequently cause TD (Kane 1994). As a result these drugs have not been widely used for the treatment of neuroleptic-induced TD. In addition, anticholinergic drugs can cause many undesirable side-effects, such as dryness of mouth, constipation, blurring of vision, and confusion (APA 1992). Ideally, cessation or reduction of the dose of neuroleptic medication is the preferred management for TD, however in clinical practice this is not always possible. In many individuals such a reduction would lead to relapse. This review focuses on whether the addition or withdrawal of anticholinergic drugs to those already receiving neuroleptic medication is likely to help TD. 2

O B J E C T I V E S 1. To examine if the use of anticholinergic drugs was associated with an improvement in neuroleptic-induced TD in people with schizophrenia or other chronic mental illness. 2. To examine if the withdrawal of anticholinergic drugs was associated with an improvement of the TD symptoms in people with schizophrenia or other chronic mental illness. 3. To examine whether there was a differential effect among the different drugs. M E T H O D S Criteria for considering studies for this review Types of studies We attempted to identify all relevant randomized controlled trials. ii. the number of people per treatment group that did not show any improvement in the symptoms of individuals on any TD scale, as opposed to some improvement; iii. deterioration in the symptoms of individuals, defined as any deleterious change on any TD scale; iv. any adverse effect, other than deterioration of symptoms of TD, as reported in the trials; v. average change in severity of TD during the trial period; and vi. average difference in severity of TD at the end of the trial. B. General mental state changes i. Deterioration in general psychiatric symptoms (such as delusions and hallucinations) defined as any deleterious change on any scale; and ii. average difference in severity of psychiatric symptoms at the end of the trial. C. Acceptability of the treatment Acceptability of the intervention to the participant group as measured by numbers of people dropping out during the trial. When feasible, the outcomes were grouped into time periods - short term (less than 6 weeks), medium term (between 6 weeks and 6 months) and long term (over 6 months). Types of participants People with schizophrenia or schizoaffective disorder or any other chronic mental illnesses, diagnosed by any criteria, irrespective of gender, age or nationality who; i. required the use of neuroleptics for more than three months; ii. developed tardive dyskinesia (diagnosed by any criteria at baseline and at least one other occasion) during neuroleptic treatment; and iii. for whom the dose of neuroleptic medication had been stable for one month or more (the same applies for those free of neuroleptics). Types of interventions i. Anticholinergic drugs (benzhexol, benztropine, biperiden, dexetimide, orphenadrine, procyclidine, scopolamine, trihexylphenidyl) compared to placebo, or no intervention; or ii. the withdrawal of the above anticholinergic drugs compared with the continuation of the treatment. Types of outcome measures Clinical efficacy was defined as an improvement in the symptoms of TD of more than 50%, on any scale, after at least six weeks of intervention. The outcomes of interest were: A. Tardive dyskinesia changes i. The number of people per treatment group that did not show an improvement in the symptoms of individuals of more than 50% on any TD scale; Search methods for identification of studies 1. Electronic searching Relevant randomized trials were identified by searching the following electronic databases: 1.1 Biological Abstracts on Silverplatter WinSPIRS 4.0 (January 1982 to March 2000) was searched using the Cochrane Schizophrenia Group s phrase for randomized controlled trials (see Group search strategy) combined with: [AND (tardive near (dyskine* or diskine*)) or (abnormal near movement* near disorder*) or (involuntar* near movement*))] This downloaded set of reports was handsearched for possible trials and researched, within the bibliographic package ProCite, with the phrase [anticholinergic* or antiparkinsonian* or benzhexol or benztropine or biperiden or dexetimide or orphenadrine or procyclidine or scopolamine or trihexyphenidyl] 1.2 CINAHL on Silverplatter WinSPIRS 4.0 (1982 - April 2000) was searched using the Cochrane Schizophrenia Group s phrase for randomized controlled trials (see Group search strategy) combined with: [AND (explode Movement-Disorders / all topical subheadings / all age subheadings) or (explode Movement-Disorders / all topical subheadings / all age subheadings) or (tardive near (dyskine* or diskine*)) or (abnormal* near movement* near disorder*) or (involuntar* near movement*) This downloaded set of reports was handsearched for possible trials and researched, within the bibliographic package ProCite, with the phrase [anticholinergic* or antiparkinsonian* or benzhexol or benztropine or biperiden or dexetimide or orphenadrine or procyclidine or scopolamine or trihexyphenidyl] 3

1.3 CCTR/CENTRAL of the Cochrane Library (Issue 2, 2000) was searched using the phrase: [((movement-disorders*:me) or (dyskinesia-drug-induced:me) or (anti-dyskinesia-agents*:me) or (tardive near (dyskine* or dyskine*)) or (neuroleptic near dyskine*) or (abnormal* near movement* near disorder*) or (involuntar* near movement*)) and (anticholinergic* or antiparkinsonian* or benzhexol* or benztroprine or biperiden or dexetimide or orphenadrine or procyclidine or scopolamine or trihexyphenidyl)] 1.4 Cochrane Schizophrenia Group s Register was searched using the phrase: [anticholinergic* or antiparkinsonian* or benzhexol or benztropine or biperiden or dexetimide or orphenadrine or procyclidine or scopolamine or trihexylphenidyl] 1.5 EMBASE on Silverplatter WinSPIRS 4.0 (January 1980 to May 2000) was searched using the Cochrane Schizophrenia Group s phrase for randomized controlled trials (see Group search strategy) combined with: [AND (( tardive-dyskinesia / all subheadings) or ( dyskinesia / all subheadings) or ( motor dysfunction / all subheadings) or (tardive near (dyskines* or diskines*)) or (abnormal* near movement* near disorder*) or involuntar* near movement*))] This downloaded set of reports was handsearched for possible trials and researched, within the bibliographic package ProCite, with the phrase [anticholinergic* or antiparkinsonian* or benzhexol or benztropine or biperiden or dexetimide or orphenadrine or procyclidine or scopolamine or trihexyphenidyl] 1.6 LILACS (January 1982 to September 1996) was searched using the CSG s phrase for randomized controlled trials (see Group search strategy) combined with the phrase: [AND ((tardive or (dyskinesia* or diskinesia*)) or (drug induced movement disorders in thesaurus))] This downloaded set of reports was handsearched for possible trials and researched, within the bibliographic package ProCite, with the phrase [anticholinergic* or antiparkinsonian* or benzhexol or benztropine or biperiden or dexetimide or orphenadrine or procyclidine or scopolamine or trihexylphenidyl] 1.7 MEDLINE on Silverplatter WinSPIRS 4.0 (January 1966 to June 2000) was searched using the Cochrane Schizophrenia Group s phrase for randomized controlled trials (see Group search strategy) combined with: [AND ((explode movement-disorders in MeSH / all subheadings) or (explode anti-dyskinesia-agents in MeSH / all subheadings) or (explode dyskinesia-drug-induced in MeSH / all subheadings) and (explode psychotic-disorders in MeSH / all subheadings) or (explode schizophrenic disorders in MeSH / all subheadings) or (tardive near (dyskine* or diskine*)) or (abnormal* near movement* near disorder*) or (involuntar* near movement*))] This downloaded set of reports was handsearched for possible trials and researched, within the bibliographic package ProCite, with the phrase [anticholinergic* or antiparkinsonian* or benzhexol or benztropine or biperiden or dexetimide or orphenadrine or procyclidine or scopolamine or trihexyphenidyl] 1.8 PsycLIT on Silverplatter WinSPIRS 4.0 (January 1974 to March 2000) was searched using the Cochrane Schizophrenia Group s phrase for randomized controlled trials (see Group search strategy) combined with the phrase: [AND ((explode movement-disorders ) or ( tardive-dyskinesia in DE) or (tardive near (dyskine* or diskine*)) or (abnormal* near movement* near disorder*) or (involuntar* near movement*))] This downloaded set of reports was handsearched for possible trials and researched, within the bibliographic package ProCite, with the phrase [anticholinergic* or antiparkinsonian* or benzhexol or benztropine or biperiden or dexetimide or orphenadrine or procyclidine or scopolamine or trihexyphenidyl] 1.9 SCISEARCH - Science Citation Index Each of the included studies was sought as a citation on the SCISEARCH database. Reports of articles that had cited these studies were inspected in order to identify further trials. 1.10 Cochrane Schizophrenia Group Trials Register The Trials Search Co-ordinator searched the Cochrane Schizophrenia Group s Trials Register (August 2012) [((*Akineton* or *Anticholinergic* or *Antimuscarinic* or *Aparkan* or *Arpicolin* or *Artane* or *Atropine* or *Banflex* or *Benapr* or *Benzatropine* or *Benzhexol* or *Benztropine* or *Biperiden* or *Biorphen* or *Bornaprine* or *Broflex* or *Buscopan or *Cholinergic* or *Cogentin* or *Cycrimine* or *Darifenacin* or *Dicycloverine* or *Diphenhydramine* or *Disipal* or *Elantrine* Or *Ethopropazine* or *Flavoxate* or *Flexon* or *Hyoscine* or *Kemadrin* or *Mephenamin* or *Muscarinic* or *Norflex* or *Oxybutynin* or *Parkin* or *Parsid* or *Orphenadrine* or *Pro-banthine* or *Procyclidine* or *Profenamine* or *Propantheline* or *Propiverine* or *Scopolamine* or *Solifenacin* or *Tolterodine* or *Trihexyphenidyl* or *Trospium*) in title abstract or index terms of REFERENCE)) and ((*dyskinesia* in title abstract or index terms of REFERENCE) and (Tardive dyskinesia in health care conditions of STUDY))] The Cochrane Schizophrenia Group s Trials Register is compiled by systematic searches of major databases, handsearches of journals and conference proceedings (see Group Module). Incoming trials are assigned to existing or new review titles. 2. Reference searching The references of all identified studies were also inspected for more studies. 3. Personal contact The first author of each included study was contacted for information regarding unpublished trials. Data collection and analysis [For definitions of terms used in this, and other sections, please refer to the Glossary.] 4

The abstract of each reference identified by the search was inspected, independently, by both reviewers, to see if the study was likely to be relevant. For articles that could possible have been RCTs, or in cases of disagreement between the two reviewers, the full article was obtained. In turn, these articles were then inspected, independently, to assess their relevance to this review. Again, where resolving disagreement by discussion was not possible, the article was added to those awaiting assessment and the authors of the study were contacted for clarification. The reviewers independently evaluated the quality of all included trials. A rating was given for each trial based on the three quality categories as described in the Cochrane Collaboration Handbook (Mulrow 1999). Only trials stated to be randomized (category A or B of the Handbook) were included in this review. Data were independently extracted by both reviewers. Again, any disagreement was discussed, the decisions documented and, where necessary, the authors of the studies were contacted for clarification. Justification for excluding references from the review was documented. If insufficient information could be extracted from the publication, a letter was sent to the first author for further clarification. There references were allocated to the Awaiting assessment list. In the absence of specific details, the reviewers assumed that subjects dropped out because they had no improvement in their TD. The results were recalculated without these assumptions in order to test the sensitivity of the results. We expected that many trials would use a crossover design. In order to exclude the potential additive effect in the second or more stages on these trials, only data from the first stage were analysed. Dichotomous outcomes were analysed by calculating odds ratios for each trial with the uncertainty in each result being expressed using confidence intervals. The odds ratios from the individual trials were combined using appropriate methods of meta-analysis. When overall results were significant the number needed to treat to produce (or prevent) one outcome was calculated by combining the overall odds ratio with an estimate of the prevalence of the event in the control groups of the trials. Continuous outcomes were analysed according to their difference in mean treatment effects and its standard deviation. Meta-analytical methods for continuous data assume that the underlying distribution of the measurements is Normal. The ratio of the mean to its standard deviation gives a crude way of assessing skew: if this ratio was less than 1.65 for any group in a trial and this can be resolved by log-transformation, the data then becoming normally distributed. It was proposed to undertake this procedure before including skewed data from any study in the analysis. Heterogeneity in the results of the trials was assessed both by inspection of graphical presentations and by calculating a test of heterogeneity. Two possible reasons for heterogeneity were prespecified: (i) that response differs according to different lengths of follow-up; (ii) that response differs according to the different drugs. These were assessed by looking at separate subgroups of trials [(i) and (ii)]. R E S U L T S Description of studies See: Characteristics of excluded studies; Characteristics of studies awaiting classification. The search strategy generated 71 references, 49 of which were excluded because they did not meet the baseline criteria for tardive dyskinesia or the anticholinergic drugs were used only as a cointervention. From the other 22 references, six were excluded because they were not randomized (Casey 1977, Gerlach 1976, Jus 1974, Lejoyeux 1993, Smith 1979, Wirshing 1989), five randomized studies were excluded because of the lack of placebo control (Bucci 1971, DiMascio 1976, Fann 1976, Lieberman 1988, Silver 1995) and in two other trials, the authors informed that the data were destroyed and no information is available (Friis 1983, Klett 1972). Fourteen studies are in awaiting assessment. Six because data required for this review were not available in the published version (Double 1993, Elie 1972, Gardos 1984, Gerlach 1978, Greil 1984, NDSG 1986 (four references)). The first authors of these papers have been contacted, two of them replied (Dr Gardos, Dr Greil), but we are still awaiting further information. Eight from updating the search in August 2012 (Gerlach 1976a, Gerlach 1977, Konig 1996, Silver 1995a, Silver 1995b, Tamminga 1977, Wirshing 1989a, Zwanikken 1976) Risk of bias in included studies None of the studies could be included in this systematic review (see results). Effects of interventions No data suitable for this review could be extracted from the relevant literature. Although eight randomized controlled trials met the inclusion criteria (Double 1993, Elie 1972, Friis 1983, Gardos 1984, Gerlach 1978, Greil 1984, Klett 1972, NDSG 1986), two were excluded because no data from the published paper were appropriate or usable and the data were no longer available (Friis 1983, Klett 1972) and the other six did not provide the relevant data for this systematic review. Double 1993 used a crossover design, but data about the first segment of the study were not available. The severity of TD was assessed in twenty seven people while they were (i) taking their usual dose of anticholinergics, (ii) on placebo or (iii) when the anticholinergic drug were withdrawal. This study reported no change in TD in any of their pre-specified comparisons. In addition, the types of anticholinergic medication used were not specified. Elie 1972 randomized 36 people to receive ethopropazine, trihexylphenidyl or placebo for two weeks. Measurements of ex- 5

trapyramidal and diskinetic symptoms were conducted, but no specific information was given for those who had TD at the baseline. Gardos 1984 compared the impact of the following interventions on TD: (i) placebo (ii) benztropine (intravenous - IV and oral) or (iii) brief neuroleptic withdrawal. Thirty six people were randomized (4:1 for the intervention procedure) to receive either benztropine (IV or oral) or placebo for the maximum of 2 weeks (personal communication). The authors concluded that the IV benztropine was associated with an inconsistent effect on TD and that the oral benztropine were more effective than the IV delivery. Some descriptive data (mean and SD) for the Dyskinesia Rating Scale (DRS) and for the Brief Psychiatric Rating Scale (BPRS) were provided and shown in Table 1. Gerlach 1978 also used a crossover design. Sixteen individuals were randomly allocated to use haloperidol or haloperidol + biperiden for four weeks (phase 2 and 3 of the study), however, no data were provided regarding the number of people allocated in each comparison. In addition, the published paper does not made it clear whether people were randomized for withdrawal of biperiden. Greil 1984 evaluated the withdrawal of biperiden in ten people with TD, using a crossover design. Some descriptive statistics (mean and SD) for the AIMS and for a local scale, for the end of a six week trial, were provided. However, the number of people in each comparison before the crossover was not specified. The authors described an important decrease in the severity of the TD symptoms in 9 people with the discontinuation of biperiden. The Nordic Dyskinesia Study Group (NDSG 1986) also used a crossover design. Thirty-three people were allocated to use: (i) chlorprothixene, (ii) perphenazine, (iii) haloperidol or (iv) haloperidol + biperiden for periods of 6 months (with 6 weeks of washout between the periods). No information was given about the first period, although they reported a moderate suppression of the TD symptoms. For the purpose of this review only three of the seven centres, where people were randomized to receive haloperidol or haloperidol + biperiden, would be included. The first authors of these papers have been contacted and we await further information. D I S C U S S I O N Currently, no statement can be made about the utility of anticholinergic drugs for the treatment of neuroleptic-induced TD. A U T H O R S C O N C L U S I O N S Implications for practice Based on the currently available data, this systematic review can provide no reliable conclusions about the use of anticholinergics (benzhexol, benztropine, biperiden, orphenadrine, procyclidine, scopolamine or trihexylphenidyl) for the treatment of neurolepticinduced TD. In addition, there is no evidence to support the suggestion that the withdrawal of these medications may benefit people with TD. In the absence of evidence one way or another, the clinician must balance the possible benefits against the potential adverse effects of the treatment. Implications for research Anticholinergics have been widely used in modern psychiatry for the treatment of extrapyramidal side effects (EPS). There is some suggestion that they may exacerbate the TD symptoms; however, the link between the use of anticholinergic and the emergence of TD may be only an epiphenomena, since people who develop EPS are thought to be more likely to receive anticholinergic and also to develop TD (APA 1992). Nevertheless, based on this systematic review, there are no data to support or discourage the use of these medications as a treatment for TD. Some suggestions to deal with the methodological problems of such trials are made: A. Sample size calculation: None of the trials awaiting assessment explained how they calculated their sample size. Several methods can be used, such as (i) the difference in the proportion of people on anticholinergics as opposed to placebo, who have a prespecified degree of symptom reduction, and (ii) the difference between the average severity of symptoms in the two groups (Taylor 1988). If, in this case, the first method was used and the prespecified degree of symptom change was 50%, a clinically important difference, the trialists may feel that there is likely to be, at best, a moderate percentage of people achieving this change. If they hoped that at least 10% more people in the anticholinergic group would achieve this improvement than in the placebo group, a trial involving in the range of 500-600 people (power = 90%; alpha = 0.5%) or, 450-500 people for a 80% power (alpha = 0.5%) would have to be undertaken. The second method of sample size calculation assumes that the average difference in the effect of the interventions comes from normally distributed results. This is not the case with trials identified so far therefore this method of sample size calculation is not applicable. The same power calculations apply for anticholinergic drugs withdrawal. B. Planning a randomized controlled trial: From the theoretical background, there is some evidence to suggest that withdrawal of anticholinergics may benefit people with neuroleptic-induced TD. If such a trial is planned, the following design elements are recommended: 6

(i) parallel-group, placebo-controlled design has benefits over crossover designs because TD has a chronic, unstable course; (ii) trials should extend for at least 6 weeks; and (iii) sample size should be sufficiently large to avoid incorrect conclusions about the effectiveness of the intervention. C. Quality of reporting of randomized controlled trials: This review should have been able to combine the data from over 200 patients from 8 separate randomized controlled trials if the reporting of data had been clear. Begg 1996, presented guidelines which have been adopted by several leading journals (CONSORT - Consolidated Standards of Reporting Trials). This group developed a checklist of 21 items that include descriptions of the randomization procedure (allocation concealment), the mechanisms of blinding/masking, number of people lost during the follow up and some details about the analysis made. Such descriptions would help people to evaluate the validity of trials, and certainly would benefit the assessment of trials to be included in this systematic review. Note: the eight citations in the awaiting classification section of the review may alter the conclusions of the review once assessed. A C K N O W L E D G E M E N T S The authors wish to thanks Dr Gardos, Dr Greil and Dr Klett for their support with more information regarding their trials. Kirsten Mason and Leanne Roberts helped in the collection of the papers. R E F E R E N C E S References to studies excluded from this review Bucci 1971 {published data only} Bucci L. The dyskinesias: a new approach. Diseases of the Nervous System 1971;32(5):324 7. Casey 1977 {published data only} Casey DE, Denney D. Pharmacological characterization of tardive dyskinesia. Psychopharmacology 1977;54:1 8. DiMascio 1976 {published data only} DiMascio A, Bernardo DL, Greenblatt DJ, Marder JE. A controlled trial of amantadine in drug-induced extrapyramidal disorders. Archives of General Psychiatry 1976;33:599 602. Fann 1976 {published data only} Fann WE, Lake CR. Amantadine versus trihexyphenidyl in the treatment of neuroleptic-induced parkinsonism. American Journal of Psychiatry 1976;133(8):940 3. Friis 1983 {published data only} Friis T, Christensen R, Gerlach J. Sodium valproate and biperiden in neuroleptic-induced akathisia, parkinsonism and hyperkinesia. Acta Psychiatrica Scandinavica 1983;67 (3):178 87. Gerlach 1976 {published data only} Gerlach J. The relationship betwen parkisonism and tardive dyskinesia. American Journal of Psychiatry 1977;134(7): 781 4. Gerlach J, Thorsen K. The movement pattern of oral tardive dyskinesia in relation to anticholinergic and antidopaminergic treatment. Internal Pharmacopsychiatry 1976;11(1):1 7. Jus 1974 {published data only} Jus K, Jus A, Gautier J, Villeneuve A, Pires P, Pineau R, Villeneuve R. Studies on the action of certain pharmacological agents on tardive dyskinesia and on the rabbit syndrome. Internal Journal of Clinical Pharmacology 1974;9(2):138 45. Klett 1972 {published data only} Klett CJ, Caffey E. Evaluating the long-term need for antiparkinson drugs by chronic schizophrenics. Archives of General Psychiatry 1972;26:374 9. Lejoyeux 1993 {published data only} Lejoyeux M, Gorwood P, Stalla-Bourdillon A, Ades J. Not available [Traduction et utilisation de l echelle de Simpson et Angus de symptomes extra pyramidaux]. L Encephale 1993;19:17 21. Lieberman 1988 {published data only} Lieberman J, Pollack S, Lesser M, Kane J. Pharmacologic characterization of tardive dyskinesia. Journal of Clinical Psychopharmacology 1988;8(4):254 60. Silver 1995 {published data only} Silver H, Geraisy N, Schwartz M. No difference in the effect of biperiden and amantadine on Parkisonian- and tardive dyskinesia-type involuntary movements: a double-blind crossover, placebo-controlled study in medicated chronic schizophrenic patients. Journal of Clinical Psychiatry 1995; 56(4):167 70. Smith 1979 {published data only} Smith JS, Kiloh LG. Six-month evaluation of thiopropazate hydrochloride in tardive dyskinesia. Journal of Neurology, Neurosurgery and Psychiatry 1979;42:576 9. Wirshing 1989 {published data only} Wirshing WC, Freidenberg DL, Cummings JL, Bartzokis G. Effects of anticholinergic agents on patients with tardive dyskinesia and concomitant drug-induced parkinsonism. Journal of Clinical Psychopharmacology 1989;9(6):407 11. References to studies awaiting assessment 7

Double 1993 {published data only} Double DB, Warren GC, Evans M, Rowlands MP. Efficacy of maintenance use of anticholinergic agents. Acta Psychiatrica Scandinavica 1993;88:381 4. Elie R, Morin L, Tetreault L. Effects of ethopropazine and of trihexyphenidyl on several parameters of the neuroleptic syndrome [Effects de l ethopropazine et du trihexylphenidyle sur quelques parametres du syndrome neuroleptique]. L Encephale 1972;61(1):32 52. Elie 1972 {published data only} Elie R, Morin L, Tetreault M. Effects of ethopropazine and of trihexyphenidyl on several parameters of the neuroleptic syndrome. Encephale 1972;61(1):32 52. Gardos 1984 {published data only} Gardos G, Cole JO, Rapkin RM, LaBrie RA, Baquelod E, Moore P, et al.anticholinergic challenge and neuroleptic withdrawal. Changes in dyskinesia and symptom measures. Archives of General Psychiatry 1984;41:1030 5. Gerlach 1976a {published data only} Gerlach J, Thorsen K. The movement pattern of oral tardive dyskinesia in relation to anticholinergic and antidopaminergic treatment. International Pharmacopsychiatry 1976;11(1):1 7. Gerlach 1977 {published data only} Gerlach J. The relationship between parkinsonism and tardive dyskinesia. American Journal of Psychiatry 1977;134 (7):781 4. Gerlach 1978 {published data only} Gerlach J, Simmelsgaard H. Tardive dyskinesia during and following treatment with haloperidol, haloperidol and biperiden, thioridazine and clozapine. Psychopharmacology 1978;59:105 12. Greil 1984 {published data only} Greil W, Haag H, Rossnagl G, Ruther E. Effect of anticholinergics on tardive dyskinesia. A controlled discontinuation study. British Journal of Psychiatry 1984; 145:304 10. Konig 1996 {published data only} Konig P, Chwatal K, Havelec L, Riedl F, Schubert H, Schultes H. Amantadine versus biperiden - a double-blind study of treatment efficacy in neuroleptic extrapyramidal movement disorders. Neuropsychobiology 1996;33(2):80 4. [MEDLINE: 8927233] NDSG 1986 {published data only} Gerlach J. Tardive dyskinesia: pathophysiological mechanisms and clinical trials. L Encephale 1988;XIV: 227 32. Gerlach J, Ahfors UG, Amthor KF. Effect of different neuroleptics in tardive dyskinesia and parkinsonism. A video-controlled multicenter study with chlorprothixene, perphenazine, haloperidol and haloperidol and biperiden. Psychopharmacology 1986;90(4):423 9. Nordik Dyskinesia Study Group. Effect of different neuroleptics in tardive dyskinesia and parkinsonism. Psychopharmacology 1986;90:423 9. Povlsen UJ, Noring U, Meidahl B, Korsgaard S, Waehrens J, Gerlach J. Not available [Neuroleptikas virkning pa tardive dyskinesier]. Ugeskr Laeger 1987;149(25):1682 5. Silver 1995a {published data only} Silver H, Geraisy N, Schwartz M. No difference in the effect of biperiden and amantadine on parkinsonian - and tardive dyskinesia-type involuntary movements: A double-blind crossover, placebo-controlled study in medicated chronic schizophrenic patients. Journal of Clinical Psychiatry 1995; 56(4):167 70. Silver 1995b {published data only} Silver H, Geraisy N, Schwartz M. No difference in the effect of biperiden and amantadine on parkinsonian- and tardive dyskinesia-type involuntary movements: A doubleblind crossover, PLACEBO-controlled study in medicated chronic schizophrenic patients. Journal of Clinical Psychiatry 1995;56(9):435. Tamminga 1977 {published data only} Tamminga CA, Smith RC, Ericksen SE, Chang S, Davis JM. Cholinergic influences in tardive dyskinesia. American Journal of Psychiatry 1977;134(7):769 74. Wirshing 1989a {published data only} Wirshing WC, Freidenberg DL, Cummings JL, Bartzokis G. Effect of anticholinergic agents on patients with tardive dyskinesia and concomitant drug-induced parkinsonism. Journal of Clinical Psychopharmacology 1989;9(6):407 11. [MEDLINE: 2574192] Zwanikken 1976 {published data only} Zwanikken GJ, Oei TT, Kimya S, Amery W. Safety and efficacy of prolonged treatment with Tremblex (dexetimide), an antiparkinsonian agent. A controlled study. Acta Psychiatrica Belgica 1976;76(3):467 79. [MEDLINE: 1020682] Additional references Alphs 1983 Alphs LD, Davis JM. Cholinergic treatments for tardive dyskinesia. Modern Problems in Pharmacopsychiatry 1983; 21:168 186. APA 1992 American Psychiatric Association. Tardive dyskinesia: a task force report of the American Psychiatric Association. Washington DC: American Psychiatric Association, 1992. Barnes 1993 Barnes TRE, Edwards JG. The side-effects of antipsychotic drugs. I. CNS and neuromuscular effects. In: Barnes TRE editor(s). Antipsychotic drugs and their side-effects. London: Harcourt Brace & Company, 1993. 8

Begg 1996 Begg C, Cho M, Eastwood S, Horton R, Moher D, Olkin I, Pitkin R, Rennie D, Schulz KF, Simel D, Stroup DF. Improving the quality of reporting of randomized controlled trials: the CONSORT statement. JAMA 1996;276(8): 637 9. Casey 1994 Casey DE. Tardive dyskinesia: pathophysiology. In: Bloom FE, Kupfer DJ editor(s). Psychopharmacology. The Fourth Generation of Progress. New York: Raven Press, 1994. Jeste 1982 Jeste DV, Wyatt RJ. Understanding and treating tardive dyskinesia. New York: The Guilford Press, 1982. Kane 1994 Kane JM. Tardive dyskinesia: epidemiological and clinical presentation. In: Bloom FE, Kupfer DJ editor(s). Psychopharmacology. The Fourth Generation of Progress. New York: Raven Press, 1994. Mulrow 1999 Mulrow CD, Oxman AD. Cochrane Collaboration Handbook [updated September 1999]. Cochrane Database of Systematic Reviews. Oxford: Update Software; 1996. Updated quarterly, 1991, issue 2. [DOI: ATD020600] Schooler 1993 Schooler NR, Keith SJ. Clinical research for the treatment of schizophrenia. Psychopharmacology Bulletin 1993;29: 431 46. Taylor 1988 Taylor DW. The calculation of sample size and power in the planning of randomized clinical trials. Millcroft Seminar 1988:1 29. Indicates the major publication for the study 9

C H A R A C T E R I S T I C S O F S T U D I E S Characteristics of excluded studies [ordered by study ID] Study Bucci 1971 Casey 1977 DiMascio 1976 Fann 1976 Friis 1983 Gerlach 1976 Jus 1974 Klett 1972 Lejoyeux 1993 Lieberman 1988 Reason for exclusion Randomised. Procyclidine vs isocarboxazid. No placebo control. Not randomised, controlled clinical study. Benztropine vs deanol. No placebo control. Randomised. Benztropine vs amantadine. No TD measure at baseline. No placebo control. Not stable dose of neuroleptics. Randomised. Amantadine vs trihylphenidyl. No placebo control. Randomised Valproate vs biperiden vs placebo. Two period crossover - no data about allocation in first period. Dr Gerlach (author) contacted and replied promptly. Data were destroyed and no more information is available Not randomised, controlled clinical trial. AMTP vs biperiden. No placebo control. Not randomised, controlled clinical trial. Benztropine vs diazepam vs diphenylhydantoin vs DL tryptophan. No placebo control. Randomised. Benztropine withdrawal vs maintenance. No information about those with TD symptoms at baseline. Dr Klett (author) contacted and replied promptly. Data were destroyed and no more information is available Not randomised, controlled clinical trial. Trihexylphenidyl vs no intervention. Randomised. Benztropine vs haloperidol vs bromocriptine vs physostigmine. No placebo control. 10

(Continued) Silver 1995 Smith 1979 Wirshing 1989 Randomised. Amantadine vs biperiden. No placebo control. Not randomized, controlled clinical trial. Benztropine vs no intervention. Not randomised, controlled clinical trial. Trihexylphenidyl vs placebo. AMTP = alpha-methyl-paratyrosine TD = tardive dyskinesia Characteristics of studies awaiting assessment [ordered by study ID] Double 1993 Attempted to contact author to see if there is any usable data available Elie 1972 Attempted to contact author to see if there is any usable data available 11

Gardos 1984 Attempted to contact author to see if there is any usable data available Gerlach 1976a To be assessed. Gerlach 1977 To be assessed. Gerlach 1978 Attempted to contact author to see if there is any usable data available 12

Greil 1984 Attempted to contact author to see if there is any usable data available Konig 1996 To be assessed. NDSG 1986 Attempted to contact author to see if there is any usable data available Silver 1995a To be assessed. 13

Silver 1995b To be assessed. Tamminga 1977 To be assessed. Wirshing 1989a To be assessed. Zwanikken 1976 To be assessed. 14

D A T A A N D A N A L Y S E S Comparison 1. Anticholinergic drugs vs placebo Outcome or subgroup title No. of studies No. of participants Statistical method Effect size 1 No data available Other data No numeric data Comparison 2. Anticholinergic withdrawal vs maintanence Outcome or subgroup title No. of studies No. of participants Statistical method Effect size 1 No data available Other data No numeric data A D D I T I O N A L T A B L E S Table 1. Changes with oral benztropine or placebo Benztropine Placebo Dyskinesia Rating Scale -2.90 (4.5) -0.81 (3.7) Brief Psychiatric Rating Scale 0.59 (6.2) 0.97 (1.0) F E E D B A C K Crossover studies Summary Category: A general comment regarding the use and interpretation of data obtained from crossover studies. The statistical questions remain unanswered and thus only data from the first treatment period can legitimately be used. However this data is rarely presented in reports of such trials leading to their exclusion from the systematic review. The author of the comment mentions that the chronic and unstable nature of TD should not disfavour a crossover trial design as suggested by the reviewers. The review would be enhanced if the authors made some recommendations on the characteristics of a crossover study that would allow its inclusion in a systematic review such as this one. 15

Reply In the TD reviews data were pooled from the first period where it was possible to do so. When impossible the results were reported without pooling. Most of the crossover trials lasted less than six weeks. Recently we have analysed data from studies using placebo and found 37.3% improved their TD symptoms. We suggest that future RCTs investigating the treatment of TD should utilise a parallel group design. Contributors Comment received from Jon Deeks, Oxford, UK, August 1997. Reply from Karla Soares, Barcelona, Spain, December 1997. W H A T S N E W Last assessed as up-to-date: 1 June 2000. Date Event Description 6 August 2012 Amended Update search of Cochrane Schizophrenia Group s Trial Register (see Search methods for identification of studies), 8 studies added to Studies awaiting classification. 4 August 2010 Amended Contact details updated. H I S T O R Y Protocol first published: Issue 2, 1996 Review first published: Issue 3, 1997 Date Event Description 14 April 2010 Amended Contact details updated. 25 April 2008 Amended Converted to new review format. 14 February 1997 New citation required and conclusions have changed Substantive amendment 16

C O N T R I B U T I O N S O F A U T H O R S Karla Soares - protocol writing, searching, trial selection, data extraction and assimilation, report writing. John McGrath - protocol writing, searching, trial selection, data extraction and assimilation, report writing. D E C L A R A T I O N S O F None. I N T E R E S T S O U R C E S O F S U P P O R T Internal sources CAPES - Ministry of Education, Brazil. Queensland Health, Australia. Universidade Federal de Sao Paulo, Brazil. External sources No sources of support supplied N O T E S Cochrane schizophrenia Group internal peer review complete (see Module). External peer review scheduled. I N D E X T E R M S Medical Subject Headings (MeSH) Antipsychotic Agents [adverse effects]; Cholinergic Antagonists [ therapeutic use]; Dyskinesia, Drug-Induced [ drug therapy; etiology] MeSH check words Humans 17