***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Patients with first-episode schizophrenia appear to respond to lower doses of neuroleptics , and to be more sensitive to developing extrapyramidal side-effects . The authors therefore compared in such patients the efficacy and extrapyramidal tolerability of comparatively low dosages of the atypical neuroleptic risperidone and of the conventional neuroleptic haloperidol . Risperidone was hypothesized to have better extrapyramidal tolerability and efficacy in treating negative symptoms . Patients were r and omly assigned under double-blind conditions to receive risperidone ( n=143 ) or haloperidol ( n=146 ) for 8 wk . The primary efficacy criterion was the estimated difference in the mean change in the Positive and Negative Symptom Scale ( PANSS ) negative score between treatment groups ; secondary efficacy criteria were changes on the PANSS total score and other PANSS subscores , and several other measures of psychopathology and general functioning . The primary tolerability criterion was the difference in baseline-adjusted occurrence rates of extrapyramidal side-effects measured with the Simpson-Angus Scale ( SAS ) compared between treatment groups . The main hypothesis was that risperidone would be superior in terms of improving negative symptoms and lowering the risk of extrapyramidal symptoms . Secondary tolerability criteria were the other extrapyramidal symptoms , measured with the Hillside Akathisia Scale ( HAS ) and the Abnormal Involuntary Movement Scale ( AIMS ) . The average mean daily doses were 3.8 mg ( s.d.=1.5 ) for risperidone and 3.7 mg ( s.d.=1.5 ) for haloperidol . There were similar , significant improvements in both treatment groups in the primary and secondary efficacy criteria . At week 8 nearly all scores of extrapyramidal side-effects indicated a significantly higher prevalence of extrapyramidal side-effects with haloperidol than with risperidone [ SAS : risperidone 36.5 % of patients ; haloperidol 51.5 % of patients ; likelihood ratio test , chi2(1)=7.8 , p=0.005 ] . There were significantly fewer drop-outs  [ risperidone n=55 , drop-out rate=38.5 % ; haloperidol n=79 , drop-out rate=54.1 % , chi2(1)=7.1 , p=0.009 ] and a longer non-discontinuation time  [ risperidone : average of 50.8 d to drop-out ; haloperidol : average of 44.0 d to drop-out ; log rank test , chi2(1)=6.4 , p=0.011 ] in the risperidone group . Risperidone and haloperidol appear to be equally effective in treating negative and other symptoms of first-episode schizophrenia .  Risperidone has better extrapyramidal tolerability and treatment retention rate than the equivalent dose of haloperidol in these patients OBJECTIVE Potency equivalents for anti-psychotic drugs are required to guide clinical dosing and for design ing and interpreting research studies . Available dosing guidelines are limited by the methods and data from which they were generated . METHOD With a two-step Delphi method , the authors surveyed a diverse group of international clinical and research experts , seeking consensus regarding antipsychotic dosing . The authors determined median clinical dosing equivalents and recommended starting , target range , and maximum doses for 61 drugs , adjusted for selected clinical circumstances . RESULTS Participants ( N=43 ) from 18 countries provided dosing recommendations regarding treatment of psychotic disorders for 37 oral agents and 14 short-acting and 10 long-acting parenteral agents . With olanzapine 20 mg/day as reference , estimated clinical equivalency ratios of oral agents ranged from 0.025 for sulpiride to 10.0 for trifluperidol . Seventeen patient and treatment characteristics , including age , hepatic and renal function , illness stage and severity , sex , and diagnosis , were associated with dosing modifications . CONCLUSIONS In the absence of adequate prospect i ve , r and omized drug-drug comparisons , the present findings provide broad , international , expert consensus-based recommendations for most clinical ly employed antipsychotic drugs . They can support clinical practice , trial design , and interpretation of comparative antipsychotic trials An international , multicenter , double-blind study was conducted in 183 patients with a first psychotic episode ( provisional schizophreniform disorder or schizophrenia ; DSM-III-R ) treated with flexible doses of risperidone or haloperidol for 6 weeks . At endpoint , 63 percent of risperidone-treated patients and 56 percent of haloperidol-treated patients were clinical ly improved ( > or = 50 % reduction in Positive and Negative Syndrome Scale total scores ) . Risperidone was better tolerated than haloperidol : the severity of extrapyramidal symptoms was significantly lower in the risperidone-treated patients ; significantly fewer risperidone-treated patients required antiparkinsonian medication ; and significantly fewer discontinued treatment because of adverse events . A post hoc analysis revealed that low doses of these antipsychotics were efficacious in some patients . Furthermore , the severity of extrapyramidal symptoms and the use of antiparkinsonian medications were significantly lower in patients receiving low doses ( maximum , < or = 6 mg/day ) than high doses ( maximum , > 6 mg/day ) of risperidone or haloperidol . These findings are consistent with the suggestion that patients with a first psychotic episode may require low doses of antipsychotic medications . Studies design ed specifically to compare low and high doses of antipsychotics are warranted to help optimize treatment for these patients OBJECTIVE This multicenter , double-blind , placebo-controlled study evaluated the efficacy and safety of three doses of sertindole ( 12 , 20 , and 24 mg/day ) and haloperidol ( 4 , 8 , and 16 mg/day ) in the treatment of psychotic symptoms for 497 hospitalized patients with schizophrenia . METHOD The patients were r and omly assigned to one of the medication groups and received treatment for 8 weeks . Changes in Positive and Negative Syndrome Scale , Scale for the Assessment of Negative Symptoms , Brief Psychiatric Rating Scale , and Clinical Global Impression scores were used as evaluations of treatment efficacy . Three rating scales were used to assess extrapyramidal symptoms as well as the occurrence of adverse events and the use of medications related to extrapyramidal symptoms . RESULTS Both sertindole and haloperidol were comparably effective in the treatment of psychosis , and all dose levels were significantly more effective than placebo . For the treatment of negative symptoms , only sertindole , 20 mg/day , was significantly more effective than placebo . For all extrapyramidal symptom measures , sertindole was clinical ly and statistically indistinguishable from placebo , and rates of extrapyramidal symptoms were not dose related . All dose levels of haloperidol produced significantly more extrapyramidal symptoms than placebo or sertindole .  Adverse events associated with sertindole treatment were mild in severity . CONCLUSIONS Sertindole is a new antipsychotic agent effective for the treatment of both the positive and negative symptoms of schizophrenia , with motor side effects that are indistinguishable from those associated with placebo The mechanism of action of a relatively new antipsychotic drug-Risperidone differs from conventional antipsychotics like Haloperidol . We compared low dosages of Risperidone with near equivalent dosages of Haloperidol in first episode drug naive Acute and Transient Psychotic disorder . A single blind r and omised four-week study protocol was employed . Highly significant and comparable efficacy as assessed by Brief Psychiatric Rating Scale and Global Assessment of Functioning Scale was seen at the end of the Study protocol in both the groups . Risperidone had significantly , an early onset of action on some of the positive as well as negative symptoms with less incidence of Extrapyramidal Symptoms in comparison to Haloperidol . We conclude that Risperidone may represent a potential useful first line agent in the treatment of Acute and Transient Psychotic Disorder BACKGROUND Studies on the effects of antipsychotics on cognitive deficits in  schizophrenia  mostly suggest a superior effect of atypical over typical compounds , although findings are inconsistent and effect sizes small . Several method ological issues , such as heterogeneous patient sample s , incomparable drug doses , effects of prior medication , construct validity , and retest effects on neuropsychological tasks , confound most results and the comparability between studies . Consequently , the conclusion concerning effects of antipsychotics on cognition is still equivocal . OBJECTIVE The present r and omized clinical trial examined the effects on cognition of comparatively low doses of a typical antipsychotic ( zuclopenthixol ) and an atypical antipsychotic ( risperidone ) in a homogeneous group of drug-naive first-episode schizophrenic patients in a longitudinal setting . METHODS First-episode schizophrenic patients who had never previously been exposed to antipsychotic treatment ( N=25 ) were r and omly allocated to treatment with flexible doses of zuclopenthixol or risperidone in an open-label design . Cognitive functions were examined both when patients were drug-naive , and after 13 weeks of treatment . A comprehensive neuropsychological battery was used in order to optimize construct validity , and principal components of cognitive functions were extrapolated in order to reduce type I errors . A healthy control group was tested at baseline and after 13 weeks , in order to examine retest effects . The cognitive domains studied were executive functions , selective attention , and reaction time . RESULTS The patients showed considerable cognitive deficits when drug-naive . There were few differential effects of risperidone and zuclopenthixol on cognitive deficits , except for a differential significance , respectively , tendency towards improved reaction and movement times in the risperidone group , and a lack of such in the zuclopenthixol group . These differences were no longer significant after covarying for extrapyramidal side effects and anticholinergic medication that were more prevalent in the zuclopenthixol group and the increases after medication were comparable with retest effects in controls . CONCLUSION The study underscores the importance of examining impact of factors , such as clinical improvement , extrapyramidal side effects , anticholinergic medication and retest effects in longitudinal efficacy studies . This study does not support efficacy of either risperidone or zuclopenthixol on cognitive functions in drug-naive schizophrenia patients after 3 months of medication , because neither could be distinguished from retest effects of the healthy control group OBJECTIVE R and omized controlled drug trials have demonstrated that antipsychotic medication is effective to rapidly improve psychotic symptomatology in first-episode psychosis . However , these results may not be generalizable to routine clinical practice . We evaluated the effectiveness , tolerability , and safety of olanza-pine , risperidone , and haloperidol in individuals with first-episode nonaffective psychosis who are representative of clinical practice and who are treated in routine clinical setting s. METHOD 172 patients participated in a practical clinical trial and were r and omly assigned to haloperidol ( N = 56 ) , risperidone ( N = 61 ) , and olanzapine ( N = 55 ) . The mean modal daily doses were 5.4 mg/day for halo-peridol , 4 mg/day for risperidone , and 15.3 mg/day for olanzapine ;  98.3 % of subjects were drug naive at baseline . Data from clinical measures of treatment response and tolerability and safety data from the 6-week acute phase of a large epidemiologic and longitudinal ( February 2001 to February 2005 ) intervention program of first-episode psychosis ( schizophrenia spectrum disorders , DSM-IV criteria ) are reported . RESULTS All 3 treatments showed similar effectiveness in reducing the severity of general , negative , and positive symptomatology after 6 weeks of treatment , as reported by mean change in total Clinical Global Impressions-Severity of Illness scale , Brief Psychiatric Rating Scale ( BPRS ) , Scale for the Assessment of Positive Symptoms , and Scale for the Assessment of Negative Symptoms scores between baseline and 6 weeks . The proportion of study subjects responding , defined as 40 % or greater BPRS total score improvement from baseline , was 57.1 % ( N = 32 of 56 ) haloperidol , 52.5 % ( N = 32 of 61 ) risperidone , and 63.6 % ( N = 35 of 55 ) olanzapine , with no statistical differences among groups . The frequency of extrapyramidal symptoms ( chi(2 ) = 24.519 ; p < .001 ) and concomitant anticholinergic medication use ( chi(2 ) = 57.842 ; p < .0001 ) was greater with haloperidol than olanzapine or risperidone . Olanzapine-treated patients had significantly more weight gain compared with the haloperidol and risperidone groups ( p < .001 ) . CONCLUSION Relatively low doses of haloperidol , risperidone , and olanzapine are equally effective for the acute treatment of first-episode nonaffective  psychosis  under usual conditions of real clinical practice OBJECTIVE This study examined the treatment response of patients with first-episode schizophrenia and schizoaffective disorder and potential predictors of response . METHOD First-episode patients were assessed on measures of psychopathology , cognition , social functioning , and biological parameters and treated according to a st and ardized algorithm . R 
    Output:
    
Olanzapine was superior to haloperidol and risperidone for reduction of negative symptoms .
Several second-generation antipsychotics were superior to haloperidol in terms of all-cause discontinuation .
Olanzapine was associated with at least one use of drugs to treat parkinsonian symptoms and quetiapine with less akathisia than haloperidol , aripiprazole , risperidone , and olanzapine , but , again , evidence was very low to low quality .
Molindone was superior to risperidone , haloperidol , and olanzapine in terms of weight gain , and superior to risperidone in terms of increase in prolactin release .
INTERPREATION Haloperidol seems to be a suboptimum treatment option for acute treatment of first-episode schizophrenia , but we found little difference between second-generation antipsychotics .