Effectiveness of haloperidol, risperidone and olanzapine in the treatment of first-episode non-affective psychosis: results of a randomized, flexible-dose, open-label 1-year follow-up comparison

The aim of this study was to investigate the long-term effectiveness and efficacy of haloperidol, risperidone and olanzapine in first-episode schizophrenia-spectrum disorders. This was a prospective, randomized, open-label study. Data for the present investigation were obtained from a large epidemiological and 3-year longitudinal intervention programme of first-episode psychosis conducted at the University Hospital Marques de Valdecilla, Santander, Spain. One hundred and seventy-four patients were randomly assigned to haloperidol (N?=?56), olanzapine (N?=?55), or risperidone (N?=?63) and followed up for 1 year. The primary effectiveness measure was all causes of treatment discontinuation. Effectiveness analyses were based on intend-to-treat populations. In addition, an analysis based on per protocol populations was conducted in the analysis for clinical efficacy. The treatment discontinuation rate for any cause was higher with haloperidol than with risperidone and olanzapine (χ(2)?=?8.517; p?=?0.014). The difference in discontinuation rate between risperidone and olanzapine was not significant (χ(2)?=?0.063; p?=?0.802). There were no significant advantages of any of the three treatments in reducing the severity of psychopathology. Risperidone and olanzapine demonstrated higher effectiveness relative to haloperidol, but the three antipsychotics were equally effective in reducing the severity of psychopathology. Specific clinical programmes and the use of second-generation antipsychotics may enhance the effectiveness of antipsychotic treatments.     

Minimum effective doses of haloperidol for the treatment of first psychotic episode: a comparative study with risperidone and olanzapine

Minimum doses of haloperidol might show similar efficacy and side-effects compared to atypical antipsychotics. The objectives of this study were to compare the efficacy of minimum doses of haloperidol with standard doses of risperidone and olanzapine on a 6-month open trial in first psychotic episode patients and to examine the effect of compliance on their outcome. Forty-two patients were recruited and started on flexible doses of these drugs. Olanzapine was given with no cost to the patients. Efficacy and side-effects were monitored every 3 months using standardized assessments. Thirty patients completed the study. All treatment groups showed improvement in positive, negative and depressive symptoms. There were no differences in side-effects among them. The haloperidol group required higher doses of anticholinergics. The rate of treatment discontinuation was higher in the risperidone group due to the direct cost. Minimum doses of haloperidol might prove to be a good choice of treatment for patients with a first episode of psychosis.     

Effect of prenatal administration of haloperidol,risperidone, quetiapine and olanzapine on spatial learning and retention in adult rats

The typical antipsychotic haloperidol and atypical antipsychotics olanzapine, quetiapine and risperidone were administered to pregnant Sprague-Dawley dams in the drinking water from Days 8 to 18 of gestation. When the offspring reached adulthood (2 months), spatial learning and short-term retention were examined using the radial arm maze. Results showed that prenatal administration of haloperidol, risperidone and quetiapine impaired learning but only haloperidol and risperidone disrupted short-term retention.     

Atypical antipsychotics versus haloperidol for treatment of delirium in acutely ill patients

Delirium is common in acutely ill patients and can result in substantial morbidity if left untreated. Atypical antipsychotics have been postulated to be safer and more effective than haloperidol for treatment of this condition. To evaluate the role of atypical antipsychotics versus haloperidol for treatment of delirium in hospitalized acutely ill adults, we searched MEDLINE (1977-September 2006) and International Pharmaceutical Abstracts (1997-September 2006) for English-language publications of clinical trials that compared atypical antipsychotics and haloperidol. Four comparative studies were identified: one double-blind, randomized study (risperidone vs haloperidol), one single-blind, randomized study (olanzapine vs haloperidol), and two retrospective studies (olanzapine vs haloperidol and quetiapine vs haloperidol). These studies demonstrated that atypical antipsychotics are as efficacious as haloperidol. In addition, they appear to be associated with a lower frequency of extrapyramidal effects, and thus are safer than haloperidol. However, these conclusions are based on a limited number of studies; larger comparative trials are needed to elucidate the role of atypical antipsychotics for treating delirium in this population.     

Time to all-cause treatment discontinuation of olanzapine compared to other antipsychotics in the treatment of schizophrenia: A systematic review and meta-analysis

Objective: This comprehensive review and meta-analysis compared the effectiveness of olanzapine and other antipsychotics in schizophrenia treatment, defining effectiveness as time to all-cause medication discontinuation (primary) and as all-cause treatment discontinuation rates. This study examined randomized clinical trials (RCTs) and observational non-interventional studies. Experimental procedures: Schizophrenia studies that compared olanzapine with individual first- (FGAs) and/or second-generation antipsychotics (SGAs) were included in the meta-analyses. Hazard ratios (HR), risk ratios (RR), and their associated 95% confidence intervals were extracted for RCTs and observational studies. Sensitivity analyses assessed the impact of sources of funding, dose of olanzapine, and allocation concealment method on final results. Results: There were 60 RCTs (N=33,360) and 27 observational studies (N=202,591) included. On time to all-cause medication discontinuation, olanzapine was significantly better than aripiprazole, quetiapine, risperidone, ziprasidone and perphenazine for RCTs and better than amisulpride, risperidone, haloperidol, and perphenazine for observational studies. There were no significant differences between olanzapine and clozapine in RCTs or observational studies. All-cause discontinuation rates in RCTs were significantly lower for olanzapine compared to all comparators except amisulpride and clozapine. In observational studies, olanzapine was less effective than clozapine. Industry-sponsored studies favored olanzapine when compared to haloperidol and perphenazine; higher dose of olanzapine favored quetiapine and perphenazine when compared to olanzapine; method of allocation concealment did not generally affect the results. Conclusion: Using a global measure of medication effectiveness (time to all-cause medication discontinuation), olanzapine appears to be more effective – in both RCTs and observational studies – than most SGAs and FGAs, except for clozapine.     

Olanzapine: an atypical antipsychotic for schizophrenia

Olanzapine is a serotonin-dopamine receptor antagonist primarily used in the treatment of psychotic illnesses. It has been shown in numerous large trials to be as equally effective as haloperidol in the acute treatment and maintenance treatment of schizophrenia. However, olanzapine was shown to be more effective than haloperidol in the treatment of negative symptoms and to cause significantly fewer extrapyramidal symptoms. Furthermore, early reports suggest that olanzapine produces less tardive dyskinesia than haloperidol, though longer follow-up data are needed. Current studies have failed to demonstrate the efficacy of olanzapine in the treatment of refractory schizophrenia. One comparison trial of olanzapine versus risperidone has indicated similar efficacy. Clinical trials in acute mania have found olanzapine to be more effective than placebo. However, there is no role for olanzapine monotherapy in bipolar disorder given current studies. Although olanzapine has shown a low rate of extrapyramidal symptoms, it is not without adverse effects. Clinically significant weight gain has been noted with olanzapine in each of the large clinical trials. The degree of weight gain is similar to clozapine and probably greater than that observed with risperidone. The long-term medical consequence of atypical antipsychotic-induced weight gain is not known at this time. While generally considered first-line drugs from an efficacy and adverse effect standpoint, pharmacoeconomic studies are needed to justify the large acquisition cost of olanzapine compared to typical agents.     

Olanzapine: an atypical antipsychotic for schizophrenia

Olanzapine is a serotonin-dopamine receptor antagonist primarily used in the treatment of psychotic illnesses. It has been shown in numerous large trials to be as equally effective as haloperidol in the acute treatment and maintenance treatment of schizophrenia. However, olanzapine was shown to be more effective than haloperidol in the treatment of negative symptoms and to cause significantly fewer extrapyramidal symptoms. Furthermore, early reports suggest that olanzapine produces less tardive dyskinesia than haloperidol, though longer follow-up data are needed. Current studies have failed to demonstrate the efficacy of olanzapine in the treatment of refractory schizophrenia. One comparison trial of olanzapine versus risperidone has indicated similar efficacy. Clinical trials in acute mania have found olanzapine to be more effective than placebo. However, there is no role for olanzapine monotherapy in bipolar disorder given current studies. Although olanzapine has shown a low rate of extrapyramidal symptoms, it is not without adverse effects. Clinically significant weight gain has been noted with olanzapine in each of the large clinical trials. The degree of weight gain is similar to clozapine and probably greater than that observed with risperidone. The long-term medical consequence of atypical antipsychotic-induced weight gain is not known at this time. While generally considered first-line drugs from an efficacy and adverse effect standpoint, pharmacoeconomic studies are needed to justify the large acquisition cost of olanzapine compared to typical agents.     

Aripiprazole

Aripiprazole is a quinolinone derivative and the first of a new class of atypical antipsychotics. The drug has partial agonist activity at dopamine D(2) and serotonin 5-HT(1A) receptors, and is also an antagonist at 5-HT(2A) receptors. In patients with acute relapse of schizophrenia or schizoaffective disorder, aripiprazole 15 to 30 mg/day was at least as effective as haloperidol 10 mg/day and had similar efficacy to risperidone 6 mg/day in well designed, 4-week, placebo-controlled trials. Negative symptoms improved earlier in the aripiprazole than the risperidone group. Efficacy of aripiprazole was observed at week 1 in several trials and was sustained throughout the study periods. Aripiprazole was superior to placebo in a 26-week trial in patients with stable, chronic schizophrenia. In a 52-week trial involving patients with acute relapsing disease, aripiprazole was similar to haloperidol as assessed by time to failure to maintain response and was superior in ameliorating negative and depressive symptoms. The incidence of extrapyramidal symptoms during aripiprazole therapy was similar to that with risperidone and placebo but lower than with haloperidol. Compared with placebo, the proportion of patients with increased plasma prolactin levels and QTc prolongation was similar in patients treated with aripiprazole 15 to 30 mg/day but was significantly increased with haloperidol and risperidone.     

Olanzapine: an updated review of its use in the management of schizophrenia

Olanzapine, a thienobenzodiazepine derivative, is a second generation (atypical) antipsychotic agent which has proven efficacy against the positive and negative symptoms of schizophrenia. Compared with conventional antipsychotics, it has greater affinity for serotonin 5-HT2A than for dopamine D2 receptors. In large, well controlled trials in patients with schizophrenia or related psychoses, olanzapine 5 to 20 mg/day was significantly superior to haloperidol 5 to 20 mg/day in overall improvements in psychopathology rating scales and in the treatment of depressive and negative symptoms, and was comparable in effects on positive psychotic symptoms. The 1-year risk of relapse (rehospitalisation) was significantly lower with olanzapine than with haloperidol treatment. In the first double-blind comparative study (28-week) of olanzapine and risperidone, olanzapine 10 to 20 mg/day proved to be significantly more effective than risperidone 4 to 12 mg/day in the treatment of negative and depressive symptoms but not on overall psychopathology symptoms. In contrast, preliminary results from an 8-week controlled study suggested risperidone 2 to 6 mg/day was superior to olanzapine 5 to 20 mg/day against positive and anxiety/depressive symptoms (p < 0.05), although consistent with the first study, both agents demonstrated similar efficacy on measures of overall psychopathology. Improvements in general cognitive function seen with olanzapine treatment in a 1-year controlled study of patients with early-phase schizophrenia, were significantly greater than changes seen with either risperidone or haloperidol. However, preliminary results from an 8-week trial showed comparable cognitive enhancing effects of olanzapine and risperidone treatment in patients with schizophrenia or schizoaffective disorder. Several studies indicate that olanzapine has benefits against symptoms of aggression and agitation, while other studies strongly support the effectiveness of olanzapine in the treatment of depressive symptomatology. Olanzapine is associated with significantly fewer extrapyramidal symptoms than haloperidol and risperidone. In addition, olanzapine is not associated with a risk of agranulocytosis as seen with clozapine or clinically significant hyperprolactinaemia as seen with risperidone or prolongation of the QT interval. The most common adverse effects reported with olanzapine are bodyweight gain, somnolence, dizziness, anticholinergic effects (constipation and dry mouth) and transient asymptomatic liver enzyme elevations. In comparison with haloperidol, the adverse events reported significantly more frequently with olanzapine in > or = 3.5% of patients were dry mouth, bodyweight gain and increased appetite and compared with risperidone, only bodyweight gain occurred significantly more frequently with olanzapine. The high acquisition cost of olanzapine is offset by reductions in other treatment costs (inpatient and/or outpatient services) of schizophrenia. Pharmacoeconomic analyses indicate that olanzapine does not significantly increase, and may even decrease, the overall direct treatment costs of schizophrenia, compared with haloperidol. Compared with risperidone, olanzapine has also been reported to decrease overall treatment costs, despite the several-fold higher daily acquisition cost of the drug. Olanzapine treatment improves quality of life in patients with schizophrenia and related psychoses to a greater extent than haloperidol, and to broadly the same extent as risperidone. CONCLUSIONS: Olanzapine demonstrated superior antipsychotic efficacy compared with haloperidol in the treatment of acute phase schizophrenia, and in the treatment of some patients with first-episode or treatment-resistant schizophrenia. The reduced risk of adverse events and therapeutic superiority compared with haloperidol and risperidone in the treatment of negative and depressive symptoms support the choice of olanzapine as a first-line option in the management of schizophrenia in the acute phase and for the maintenance of treatment response.     

Efficacy of olanzapine and ziprasidone for the treatment of schizophrenia: a systematic review

It is difficult to determine the relative efficacy of atypical antipsychotics for the treatment of schizophrenia, based on the available literature. The purpose of this article is to review and compare the efficacy of two atypical antipsychotics: olanzapine and ziprasidone.This review focused on randomised trials in which these two antipsychotics were compared with placebo, conventional antipsychotics and each other. Common efficacy measures were the Brief Psychiatric Rating Scale, Positive and Negative Syndrome Scale and Schedule for Assessment of Negative Symptoms. When sufficient data were available, the mean treatment effect (with 95% confidence intervals) was computed and presented.Olanzapine was consistently found to be significantly superior to placebo and comparable with, or superior to, haloperidol for the treatment of overall, positive and negative schizophrenic symptoms. Ziprasidone appears to have significantly greater efficacy than placebo for overall and negative symptoms, but it remains uncertain whether ziprasidone is comparable in efficacy with conventional antipsychotics such as haloperidol. Two unpublished clinical trials have directly compared olanzapine and ziprasidone. One of these trials found no significant efficacy differences between the two drugs, whereas the results of the other study favoured olanzapine.Compared with ziprasidone, olanzapine has a larger body of evidence supporting its efficacy, and a greater proportion of findings for olanzapine have been published, allowing for greater scrutiny of results. Both drugs appear to be superior to placebo for the treatment of overall and negative symptoms of schizophrenia, but olanzapine generally compares more favourably with conventional antipsychotics. Firm conclusions regarding the comparison between olanzapine and ziprasidone require additional published trials on ziprasidone, particularly in direct comparison with olanzapine.     

All-cause treatment discontinuation in schizophrenia during treatment with olanzapine relative to other antipsychotics: an integrated analysis

OBJECTIVES: Treatment continuation, as measured by time to all-cause treatment discontinuation, is a broad measure of overall treatment effectiveness. This integrated analysis compared the likelihood of discontinuation from olanzapine treatment versus other antipsychotics among patients with schizophrenia. METHODS: Clinical trials of all sponsors were included if they met the following criteria: double-blind, randomized, comparative; duration of 12 weeks or longer; no mandatory discontinuation before 12 weeks; and schizophrenia-spectrum disorders; 20 patients or more per treatment. Weighted mean hazard ratios and 95% confidence intervals were calculated from discontinuation time. Meta-analyses were performed for the following comparators that had at least 2 studies: haloperidol (5 studies), risperidone (5 studies), ziprasidone (2 studies), clozapine (3 studies), and perphenazine (2 studies) (13 studies in total; 3 included more than 1 comparator). Only 1 eligible published study was found for fluphenazine, amisulpride, and quetiapine; therefore, meta-analyses could not be performed for these comparators. RESULTS: Significantly (P < 0.05) greater likelihood of discontinuation relative to olanzapine treatment (hazard ratio [95% confidence interval]) was observed for haloperidol (1.4 [1.2-1.7]), risperidone (1.3 [1.1-1.6]), ziprasidone (1.6 [1.4-2.0]), and quetiapine (1.4 [1.1-1.9]), but not clozapine (1.2 [0.9-1.6]), fluphenazine (1.8 [0.8-4.3]), perphenazine (1.3 [0.7-2.1]), or amisulpride (1.1 [0.8-1.6]). CONCLUSIONS: These data suggest that patients with schizophrenia and related disorders may continue olanzapine treatment longer than haloperidol, risperidone, ziprasidone, or quetiapine treatment.     

Asenapine: a new antipsychotic option

Asenapine is a new psychopharmacologic agent approved for the acute and maintenance treatment of schizophrenia and the acute and maintenance treatment of manic and mixed episodes associated with bipolar I disorder. The efficacy of asenapine in treating schizophrenia was evaluated in four 6-week studies in which placebo and active controls (risperidone, olanzapine, and haloperidol) were used. Two 3-week placebo-controlled trials examined the efficacy of asenapine and active control (olanzapine) in the treatment of bipolar I disorder. Asenapine demonstrated efficacy in relation to placebo for 2 of the acute schizophrenia trials and both trials examining the acute treatment of bipolar I disorder. Several factors should be examined when considering asenapine therapy in relation to other antipsychotics including efficacy, atypicality of receptor binding, obstacles to administration and compliance, and finally cost. No efficacy advantage is evident with asenapine over other antipsychotic agents. Barriers to achieving compliance with asenapine include the recommendations of twice daily dosing, the need to avoid food and liquids for at least 10 minutes postadministration, the need for patient cooperation with sublingual administration, and the low bioavailability of the tablet if swallowed. Finally, no cost advantage is evident for using asenapine in comparison to the already available generic risperidone or other soon-to-be generic atypical antipsychotics.     

Cost analysis of the treatment of schizophrenia in the UK. A simulation model comparing olanzapine, risperidone and haloperidol

OBJECTIVE: To compare the costs of 2 atypical drug therapies (olanzapine and risperidone) with one another and with a conventional antipsychotic (haloperidol) in the treatment of schizophrenia. DESIGN AND SETTING: The analysis is based on a simulation model with parameter values taken mainly from clinical trial data in patients with schizophrenia, and was conducted within a UK context. RESULTS: The 3 therapies are approximately cost neutral over a 5-year period (olanzapine 35,701 Pounds, risperidone 36,590 Pounds and haloperidol 36,653 Pounds). There is evidence of greater efficacy with the atypical drugs [average percentage of 5 years with Brief Psychiatric Rating Scale (BPRS) scores < 18: olanzapine 63.6%, risperidone 63.0% and haloperidol 52.2%]. The cost and efficacy differences between the 2 atypical drugs are too small to rank them in terms of cost effectiveness. Extensive sensitivity analysis does not change any of the main conclusions. CONCLUSIONS: Given evidence of efficacy gains to the atypical drugs, these represent cost-effective treatment options. Prospective data from nontrial treatment settings would help substantiate the model findings.     

A review of the efficacy, tolerability and safety of sertindole in clinical trials

Sertindole is a non-sedating atypical antipsychotic agent with high selectivity for dopaminergic neurons in the mesolimbic system. In pivotal clinical trials, sertindole has demonstrated significantly greater efficacy than placebo against both the positive and negative symptoms of schizophrenia. In addition, sertindole has had at least similar efficacy to haloperidol and risperidone against positive symptoms, and significantly greater efficacy than haloperidol and risperidone against negative symptoms. The incidence of extrapyramidal symptom (EPS)-related adverse events and the rate of medication used to treat EPS in patients receiving clinically effective doses of sertindole in clinical trials were similar to those observed in placebo recipients and significantly less than those in haloperidol recipients. The incidence of QTc interval prolongation of 500 ms or greater with therapeutic dosages of sertindole has also been low. In general, sertindole has been well tolerated in clinical trials. Unlike other antipsychotic agents, sertindole has not been associated with cognitive impairment, and can actually improve cognitive function. Observational studies have shown that the efficacy and tolerability of sertindole observed in the clinical trial situation are emulated in a naturalistic setting. Large cohort analyses (N > 8000) have shown that all-cause and cardiovascular mortality is no greater with sertindole than with risperidone or olanzapine.     

One-year clinical and economic consequences of oral atypical antipsychotics in the treatment of schizophrenia

ABSTRACT

Objective: To assess the clinical and economic consequences of oral atypical antipsychotic treatment (aripiprazole, olanzapine, paliperidone ER, quetiapine, risperidone, and ziprasidone) in schizophrenia over one-year from a US healthcare system perspective.

Methods: The decision model captured rates of discontinuation, symptom response, frequency and duration of relapse, adverse events (extrapyramidal symptoms and weight gain), resource utilization, and unit costs. Published randomized, double-blind, placebo-controlled clinical trial data were used to obtain response rates for comparators. Published clinical trial data from long-term effectiveness trials reflective of typical clinical settings were used for time on therapy, rates of discontinuation, likelihood of switching, relapse rates, and adverse event rates. Drug costs were based on Wholesale Acquisition Cost weighted by Wolters Kluwer Retail and First Databank Pricing drug utilization data. PharMetrics Patient-Centric database was utilized for length of stay, frequency of relapse, and unit cost of healthcare resource data. A clinical expert panel provided resource-use information not available in published literature or healthcare databases. To test the robustness of the findings, sensitivity analyses were performed using plausible ranges of key model input parameters.

Results: The model estimated that, over 1 year, clinical outcomes of patients administered oral atypical antipsychotics would not vary considerably. This is partly due to differences ‘washing out’ because of frequent switching and discontinuation of medication. Economic outcomes did vary among pharmacotherapies: paliperidone ER was associated with cost savings in direct medical costs per patient per year compared to risperidone (cost savings using paliperidone ER vs. risperidone: $793), quetiapine ($1191), olanzapine ($1259), ziprasidone ($2159), and aripiprazole ($2204)). Limitations of this analysis include the absence of direct head-to-head long-term comparative data for antipsychotics. However, the results of the decision analysis held true when tested through a multitude of sensitivity analyses.

Conclusion: This modeling study showed that paliperidone ER had the most favorable clinical and economic outcomes compared to other oral atypical antipsychotics for patients with schizophrenia. The analysis supports the notion that frequent discontinuation of medication is a problem with all oral antipsychotic treatments for schizophrenia.     

Tolerability of atypical antipsychotics.

Atypical antipsychotics are expected to be better tolerated than older antipsychotics because of their lower propensity to cause certain adverse effects. All atypical drugs have been shown to cause fewer acute extrapyramidal symptoms (EPS) than a standard typical agent (usually haloperidol) and some (clozapine, sertindole and quetiapine) appear to cause these effects no more often than placebo. In the longer term, clozapine, olanzapine and (less robustly) other atypical antipsychotics are thought to cause less tardive dyskinesia than typical antipsychotics. Problems caused by hyperprolactinaemia occur less often with some atypical antipsychotics than with typical drugs although risperidone and amisulpride appear to have no advantages in this respect. Other adverse effects may occur as frequently with some atypical antipsychotics as with some typical drugs. Clozapine, risperidone and quetiapine are known to cause postural hypotension; clozapine, olanzapine and quetiapine are clearly sedative; and anticholinergic effects are commonly seen with clozapine, and, much less frequently, with olanzapine. Some adverse effects are more frequent with atypical drugs. Idiosyncratic effects seem particularly troublesome with clozapine and, to a lesser extent, sertindole, olanzapine and zotepine. Bodyweight gain is probably more problematic with atypical antipsychotics than with typical drugs. Overall tolerability, as judged by withdrawals from therapy, is not clearly proven to be better with atypical drugs, although some individual trials do indicate an advantage with atypical agents. Differences in tolerability between individual atypical antipsychotics have not been clearly shown. The tolerability profile of atypical drugs certainly benefits from a lower incidence of acute EPS effects, along with less certain or less uniform benefits in symptomatic hyperprolactinaemia or tardive dyskinesia. Other, perhaps more trivial, adverse effects militate against their good tolerability, and effects such as bodyweight gain may severely reduce tolerability. Without clear advantages in tolerability in patient groups used in trials, drug choice in regard to adverse effects should continue to be on a patient to patient basis.     

Aripiprazole: a review of its use in the management of schizophrenia in adults

Oral aripiprazole (Abilify?) is an atypical antipsychotic agent that is approved worldwide for use in adult patients with schizophrenia. It is a quinolinone derivative that has a unique receptor binding profile as it exhibits both partial agonist activity at dopamine D(2) receptors and serotonin 5-HT(1A) receptors and antagonist activity at 5-HT(2A) receptors. In several well designed, randomized, clinical trials of 4-6 weeks duration, aripiprazole provided symptomatic control for patients with acute, relapsing schizophrenia or schizoaffective disorder. Furthermore, following 26 weeks' treatment, the time to relapse was significantly longer for patients with chronic, stabilized schizophrenia receiving aripiprazole compared with those receiving placebo. Using a variety of efficacy outcomes, aripiprazole showed a mixed response when evaluated against other antipsychotic agents in randomized clinical trials. Longer-term data showed that improvements in remission rates and response rates favoured aripiprazole over haloperidol, although, the time to failure to maintain a response was not significantly different between the treatment arms. On the other hand, improvements in positive and negative symptom scores mostly favoured olanzapine over aripiprazole, although, the time to all-cause treatment discontinuation was not significantly different between the two treatments. Several open-label, switching trials showed that aripiprazole provided continued control of symptoms in patients with schizophrenia or schizoaffective disorder. Using a variety of efficacy outcomes or quality-of-life scores, longer-term treatment generally favoured patients switched to receive aripiprazole compared with standard-of-care oral antipsychotics. Aripiprazole was generally well tolerated in patients with schizophrenia. In particular, its use seems to be associated with a lower incidence of extrapyramidal symptoms than haloperidol and fewer weight-gain issues than olanzapine. Aripiprazole also showed a favourable cardiovascular tolerability profile and its use was associated with a reduced risk of metabolic syndrome than placebo or olanzapine. As a consequence, aripiprazole may provide a more cost-effective treatment option compared with other atypical antipsychotics. In conclusion, oral aripiprazole provides an effective and well tolerated treatment alternative for the acute and long-term management of patients with schizophrenia.     

Therapeutic drug monitoring of antipsychotics

Therapeutic drug monitoring of conventional and atypical antipsychotics offers numerous clinical advantages to the clinician. These include cost savings, decreased risk of toxicity, and improved compliance. Among these drugs, studies of haloperidol, olanzapine, and clozapine have provided the most compelling data to justify therapeutic drug monitoring. Among atypical antipsychotics, although data document the utility of routine monitoring of clozapine and olanzapine blood levels, there are no similar data available for either risperidone or quetiapine. Additionally, the utility of therapeutic drug monitoring is enhanced by the availability of prospective dosing schemes for haloperidol, olanzapine, and clozapine.