Haloperidol decanoate and flupenthixol decanoate in schizophrenia. A long-term double-blind cross-over comparison. Zuclopenthixol decanoate and haloperidol decanoate in chronic schizophrenia: a double-blind multicentre study. Haloperidol decanoate v. fluphenazine decanoate as maintenance therapy in chronic schizophrenic in-patients. Minimal effective dose and relapse--double-blind trial: haloperidol decanoate vs. placebo. Double-blind comparison of haloperidol decanoate and fluphenazine decanoate effectiveness, side-effects, dosage and serum levels during a six months' treatment for relapse prevention. Addition of lithium to haloperidol in non-affective, antipsychotic non-responsive schizophrenia: a double blind, placebo controlled, parallel design clinical trial. A double-blind, controlled clinical trial of haloperidol decanoate and fluphenazine decanoate in the maintenance treatment of schizophrenia. Olanzapine versus haloperidol in the treatment of patients with chronic schizophrenia: results of the Japan multicenter, double-blind olanzapine trial. Does cognitive function improve with quetiapine in comparison to haloperidol?
Thirty-two schizophrenic patients, previously treated with antipsychotics, were treated with haloperidol decanoate and flupenthixol decanoate in a double-blind cross-over study. The drugs were given for 24 weeks each at an individually adapted dose. The last three injections of either drug were given at fixed 4-week intervals. The mean dose over the two treatment periods changed from 131 mg (start) to 151 mg (week 24) in the haloperidol decanoate group and from 56 mg to 66 mg in the flupenthixol decanoate group, the inter-drug ratio being 2.3:1. During the first study period, the patients' condition remained rather stable with both drugs. After crossing-over, the symptoms were further reduced with haloperidol decanoate but increased with flupenthixol decanoate. Side effects of the two drugs were comparable and were generally few and mild. It was concluded that 4-week intramuscular administration of haloperidol decanoate provides appropriate control of schizophrenic symptoms, but that flupenthixol decanoate should be dosed at shorter intervals. Zuclopenthixol decanoate (ZPT-D) and haloperidol decanoate (HAL-D) were compared in the maintenance treatment of chronic schizophrenic patients. All patients were treated with either ZPT-D or HAL-D for at least 3 months and were then randomly allocated to treatment with either ZPT-D (100-600 mg every 4 weeks) or HAL-D (38-200 mg every 4 weeks) for 9 months. Sixty-four patients entered the study. Three patients were only assessed at baseline. Four patients in the HAL-D group were withdrawn because of deterioration. One patient in the ZPT-D group committed suicide. Fifty-six patients completed the trial. The assessment programme comprised Clinical Global Impressions by psychiatrists and nurses, the Brief Psychiatric Rating Scale (BPRS), Montgomery-Asberg Depression Rating Scale (MADRS), UKU Side Effect Scale and Simpson-Angus Scale, Ratings were made at baseline and after 12, 24 and 36 weeks of treatment. The severity of illness scores remained almost constant. The only between-group difference was recorded at month 6 in favour of ZPT-D. The BPRS total scores were reduced significantly in both groups with no between-group differences. The depression scores on the MADRS were very low. Both treatments caused few and mild side effects according to the UKU Side Effect Scale and the Simpson-Angus scale, and there were no significant differences between the groups. Both ZPT-D and HAL-D seem to be effective in the maintenance treatment of chronic schizophrenic patients and cause few side effects. The injections of ZPT-D and HAL-D can be given at 4-week intervals. In a double-blind study of 38 chronic schizophrenic in-patients, haloperidol decanoate was compared with fluphenazine decanoate as maintenance therapy over 60 weeks. Both drugs were given by injection at 4-week intervals. Haloperidol and fluphenazine were assumed to be equipotent; the mean starting dose of the former was 127 mg and of the latter 106 mg. The number of withdrawals over 60 weeks was similar in both groups but relapses, strictly defined, were significantly more frequent in the haloperidol group. When patients were switched to haloperidol, Parkinsonism diminished more quickly than in the fluphenazine group, but after 60 weeks there was no difference in severity in the two drug groups. The higher relapse rate and the quicker reduction in Parkinsonism in the haloperidol group might be due to a misjudgement in equivalent doses of the two drugs. Plasma haloperidol steady state levels were reached in most patients by 8-12 weeks. Plasma neuroleptic and prolactin levels, week-by-week systemic drug availability and Parkinsonism showed less variation between injections with haloperidol than with fluphenazine. Fifty-six chronic schizophrenic patients were randomized into haloperidol decanoate (HD) or placebo groups for 48 weeks of double-blind treatment. The double-blind trial was preceded by a 15-week single-blind run-in period, during which all patients were treated with 60 mg of HD (approximately corresponding to 3.6 mg orally/day) every fourth week (except for the second injection, which was given after 3 weeks). Eight relapses occurred during the run-in period, and seven other patients refused further participation. The remaining 41 patients were then treated double blind, either with HD, 60 mg/4 weeks (18 patients), or with placebo (23 patients). Two patients (11%) in the HD group and 16 (69%) in the placebo group relapsed during the 48-week double-blind period. The plasma concentrations of haloperidol were measured every fourth week in both groups. Steady state was reached after 11 weeks. The mean steady-state level was 6.3 nmol/L. In the placebo group, a 50% decrease in the mean haloperidol plasma concentration was seen 8 weeks after withdrawal of haloperidol. The haloperidol plasma concentration was a predictor of relapse. There was no statistical difference between the treatment groups regarding extrapyramidal symptoms. More biperiden, however, was used in the HD group, while the placebo patients took more sedatives. The results of this study show that the relatively low and fixed dose of 60 mg of HD every fourth week was superior to placebo in preventing relapse in schizophrenia.(ABSTRACT TRUNCATED AT 250 WORDS) In this present study 31 schizophrenic patients were treated for six months for relapse prevention under double-blind conditions with either haloperidol decanoate (22) or fluphenazine decanoate (9). In respect of the prophylactic action, both depot neuroleptics proved to be equal during the comparatively short period of observation. In both groups a psychotic relapse occurred that could not be managed by increasing the depot dosage. No side-effects worth mentioning appeared in either group of patients; patients under haloperidol decanoate, however, only required half the quantity of anti-parkinson medication as compared with patients treated with fluphenazine decanoate, and also displayed extrapyramidal motor symptoms (EPMS) to a lesser degree. Patients received a mean monthly injection of 80 mg of Haloperidol, reaching steady-state serum levels of about 3 ng/ml in the third injection interval. Fluphenazine serum levels known so far for seven patients amount to 0.8 ng/ml after fluphenazine injections of 21 mg every 14 days. This double-blind placebo controlled, parallel design clinical trial compared the therapeutic effects of the addition of lithium or placebo to haloperidol in 21 seriously ill state hospital patients with DSM-III-R schizophrenia, who did not have concurrent affective disorders and who had not responded to previous trials of conventional antipsychotic medication. During a baseline period of 6 weeks, patients were switched to a stable dose of haloperidol (mean +/- SD dose = 13.6 +/- 8.1 mg/day). Patients were then randomized to receive either lithium or placebo in addition to haloperidol for 8 weeks (mean +/- SD lithium level = 0.98 +/- 0.13 mEq/l). Symptoms and side effects were assessed weekly. Improvement in symptoms correlated with the non-blind adjustment of antipsychotic dose, but not with lithium or placebo treatment. Side effects ratings did not differ between the two groups, but one patient developed a reversible delirium associated with combined lithium/haloperidol treatment. For these long-term, severely ill patients, combined treatment afforded no advantage over treatment with haloperidol alone. nan This randomized double-blind trial was conducted to test the efficacy and safety of olanzapine in Japanese patients with schizophrenia. Importantly, this study also represents the first large clinical trial of olanzapine conducted in an Asian population. Patients (n = 182) were randomly assigned to treatment with olanzapine or haloperidol over a period of 8 weeks. The primary analyses included: (i) a test of non-inferiority of olanzapine compared with haloperidol in efficacy using the Final Global Improvement Rating (FGIR); and (ii) comparison between the treatment groups in extrapyramidal symptom severity using the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). Olanzapine was comparable to haloperidol in efficacy in treating positive symptoms and significantly superior in treating negative symptoms. Extrapyramidal symptom severity was significantly improved for olanzapine-treated patients versus haloperidol-treated patients. Olanzapine was shown to be more effective and better tolerated than haloperidol in the treatment of Japanese patients suffering from chronic schizophrenia. Recent evidence suggests that schizophrenia patients taking atypical antipsychotic medications may perform better on some tests of cognitive function than those treated with older antipsychotics. The current study compared the effects of quetiapine and haloperidol on measures of executive function, memory and attention. Subjects were 58 stable outpatients with schizophrenia (DSM III-R) who received a battery of cognitive tests as part of a randomized, double-blind, multi-site clinical efficacy study conducted by AstraZeneca Pharmaceuticals. Cognitive assessments were conducted prior to randomization when patients were receiving < or =30 mg haloperidol or equivalent (mean: 9.2mg/day haloperidol equivalents), and again after 24 weeks of fixed-dose treatment with either quetiapine 600 or 300 mg/day or haloperidol 12 mg/day. Analyses of covariance with planned comparisons were used to compare scores on cognitive measures at the end of 24 weeks by treatment group with baseline cognitive function scores used as covariates. Patients receiving quetiapine 600 mg/day improved to a greater extent than patients receiving haloperidol on overall cognitive function (p<0.02). Specific differences were found for executive function (Verbal Fluency Test, p<0.04), attention (Stroop Color Word Test, p<.03) and verbal memory (Paragraph Recall Test, p<0.02). Treatment group differences were not solely due to benztropine use, medication side effects, or changes in symptomatology. Treatment with quetiapine at higher doses (600 mg/day) relative to haloperidol appears to have a positive impact on important domains of cognitive performance that have been found to predict role function and community outcomes in patients with schizophrenia.
Haloperidol decanoate may have a substantial effect in improving the symptoms and behaviour associated with schizophrenia in comparison to placebo, but data are remarkably sparse. 
There are no discernible differences between the depot form of haloperidol and its oral equivalent. For those needing and willing to take the drug, the means of administration is then a matter of individual choice and clinical judgement. As there are no clear differences between haloperidol decanoate and other depots, the choice of depot medication could also be individually tailored and patient preference exercised.
Well-conducted and reported randomised trials are needed comparing haloperidol decanoate with other depots but the comparison of haloperidol decanoate to oral antipsychotics is a priority.