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PubMed2006

A prospective, multicenter, randomized, parallel-group, open-label study of aripiprazole in the management of patients with schizophrenia or schizoaffective disorder in general psychiatric practice: Broad Effectiveness Trial With Aripiprazole (BETA).

OBJECTIVE: BETA was designed to evaluate the overall effectiveness of aripiprazole in patients with schizophrenia or schizoaffective disorder treated in a general psychiatry outpatient practice setting. METHODS: In this 8-week, multicenter, open-label study, 1,599 outpatients with schizophrenia or schizoaffective disorder were randomly assigned to receive either aripiprazole (n=1,295) or another antipsychotic medication (safety control [SC] group; n=304). Aripiprazole was initiated at 15 mg/d with the option to adjust between 10-30 mg/d. The SC medication was specifically selected for each patient by the clinician and dosed according to prescribing guidelines for that medication. The primary effectiveness measure was the Clinical Global Impression-Improvement (CGI-I) score of the aripiprazole group at study end point. Secondary measures included response rates and preference of medicine (POM) ratings by patients and caregivers. RESULTS: Sixty-five percent of aripiprazole patients completed the study. The mean aripiprazole dose at end point was 19.9 mg/d, with approximately 39% of patients starting and remaining at 15 mg/d. At end point, the mean CGI-I score of 2.77 demonstrated that aripiprazole was minimally to moderately effective; the mean CGI-I score for the SC group was 3.59 indicating minimally effective to no change. Fifty-three percent of aripiprazole patients responded to treatment (CGI-I score of 1 or 2; last-observation-carried-forward [LOCF]), and approximately 71% of patients and caregivers rated aripiprazole as better than the prestudy medication on the POM (LOCF). Incidence and severity of adverse events (AEs) were similar to those reported in double-blind, randomized, placebo-controlled aripiprazole clinical trials. The most frequent AE in the aripiprazole group was insomnia (24%). CONCLUSIONS: Aripiprazole was effective for the treatment of schizophrenia and schizoaffective disorder in a general psychiatry outpatient practice setting. Overall, aripiprazole was found to be effective by the treating clinician and well accepted by patients and caregivers over the 8-week treatment course.

Adult↗

PubMed2004

Aripiprazole: a review of its use in schizophrenia and schizoaffective disorder.

UNLABELLED: Aripiprazole, a quinolinone derivative, is an atypical antipsychotic drug indicated for the treatment of adult patients with schizophrenia. Aripiprazole 10 or 15 mg once daily is effective and well tolerated in patients with schizophrenia or schizoaffective disorder. Although aripiprazole has only been directly compared with haloperidol and olanzapine in treatment-responsive patients to date, current data generally indicate that aripiprazole has a beneficial profile in terms of a low potential for bodyweight gain. Dosage titration is not necessary and the drug is effective in the first few weeks of treatment. Head-to-head comparative trials with atypical antipsychotic agents are required, as are long-term (> or =1 year) studies, to fully define the position of aripiprazole in relation to other antipsychotic drugs. Aripiprazole is a valuable new therapeutic option in the management of patients with schizophrenia. PHARMACOLOGICAL PROPERTIES: Aripiprazole is a quinolinone derivative with a high affinity for dopamine D2 and D3 receptors, and serotonin 5-HT1A, 5-HT2A and 5-HT2B receptors. The mechanism of action of aripiprazole is not yet known, but evidence suggests that its efficacy in the treatment of the positive and negative symptoms of schizophrenia and its lower propensity for extrapyramidal symptoms (EPS) may be attributable to aripiprazole's partial agonist activity at dopamine D2 receptors. At serotonin 5-HT1A receptors, in vitro studies have shown that aripiprazole acts as a partial agonist whereas at serotonin 5-HT2A receptors aripiprazole is an antagonist. The main active metabolite, dehydro-aripiprazole, has affinity for dopamine D2 receptors and thus has some pharmacological activity similar to that of the parent compound. Aripiprazole is rapidly absorbed after oral administration. The mean time to peak plasma concentration is 3 hours following multiple-dose administration of aripiprazole 10 or 15 mg and the absolute oral bioavailability of the drug is 87%. Steady-state plasma drug concentrations are achieved by 14 days; however, the drug appears to accumulate over this period, since mean peak plasma concentration and mean area under the plasma concentration-time curve values of aripiprazole 10 or 15 mg/day are 4-fold greater on day 14 than on day 1. This accumulation may be expected, since the mean elimination half-life of a single dose of aripiprazole is about 75 hours. Aripiprazole has extensive extravascular distribution and more than 99% of aripiprazole and dehydro-aripiprazole (the main active metabolite of aripiprazole) is bound to plasma protein. Elimination of the drug is primarily hepatic; the cytochrome P450 (CYP) 3A4 and CYP2D6 enzyme systems transform aripiprazole to dehydro-aripiprazole, with the latter enzyme system subject to genetic polymorphism. Thus, dosage adjustment of aripiprazole is necessary when it is coadministered with CYP3A4 and CYP2D6 inhibitors (since aripiprazole concentration is increased) and with inducers of CYP3A4 (since aripiprazole concentration is decreased). THERAPEUTIC EFFICACY: The efficacy of aripiprazole has been demonstrated in patients with schizophrenia or schizoaffective disorder. In general, significant reductions from baseline in mean Positive and Negative Syndrome Scale total, positive and negative symptom scores, and Clinical Global Impression Severity of Illness scores were observed in patients with acute relapse of chronic schizophrenia or schizoaffective disorder receiving recommended (10 or 15 mg/day) or higher-than-recommended (20 or 30 mg/day) dosages of aripiprazole versus those receiving placebo in three well controlled, short-term trials. No additional therapeutic benefit was observed at the higher-than-recommended dosages. The drug is effective as early as the first or second week of treatment. The efficacy of aripiprazole was maintained for up to 52 weeks. The drug was significantly more effective than placebo in preventing relapse in patients with stable chronic schizophrenia in a 26-week, randomised trial. In a 52-week trial in patients with acute relapse of schizophrenia, the percentage of responders maintaining a response at study end was 77% of aripiprazole versus 73% of haloperidol recipients. Aripiprazole may improve cognitive function. In a nonblind, 26-week trial, patients with chronic schizophrenia receiving aripiprazole 30 mg/day experienced similar (general cognitive function) or better (verbal learning) changes from baseline in the neurocognitive parameters evaluated compared with recipients of olanzapine 10-15 mg/day. TOLERABILITY: Aripiprazole 10-30 mg/day was generally well tolerated. The tolerability profile of aripiprazole was broadly similar to that observed with placebo in a meta-analysis of short-term trials in patients with acute relapse of schizophrenia or schizoaffective disorder and in a 26-week trial in patients with chronic stable schizophrenia. The most frequent treatment-emergent adverse events included insomnia and anxiety, and additionally, headache and agitation (in short-term trials) or akathisia and psychosis (in a 52-week trial). In general, the drug was associated with a placebo-level incidence of EPS and EPS-related adverse events. Significantly fewer aripiprazole recipients experienced EPS-related adverse events than haloperidol recipients in a 52-week trial. Changes in severity of EPS were minimal and usually no different from those observed with placebo. Moreover, there was less severe EPS in the aripiprazole group than the haloperidol group in a long-term trial. Treatment-emergent tardive dyskinesia was reported in only 0.2% of patients receiving aripiprazole (short-term trials), an incidence similar to that seen in placebo recipients (0.2%). Aripiprazole has a low propensity to cause clinically significant bodyweight gain, hyperprolactinaemia or corrected QT interval prolongation in patients with schizophrenia or schizoaffective disorder. In addition, there were no clinically relevant differences in mean changes from baseline in measures of diabetes and dyslipidaemia between the aripiprazole or placebo groups in a 26-week, placebo-controlled trial.

Antipsychotic Agents↗

PubMed2005

Aripiprazole: new drug. Just another neuroleptic.

(1) Neuroleptics are the standard treatment for schizophrenia. The first drugs of this class, such as haloperidol, were marketed nearly 50 years ago, and neuroleptics released over the past 15 last years have provided no major advance. (2) Aripiprazole is a new neuroleptic licensed for the treatment of schizophrenia. (3) Five double-blind placebo-controlled trials lasting 4 to 6 weeks showed that aripiprazole was a little more effective than placebo at daily doses of 10 mg to 30 mg, without a clear dose-response relationship. Based on the least demanding definition of "treatment response" (a 30% reduction in the PANSS global score), less than 50% of patients responded to aripiprazole. (4) In a double-blind trial lasting 6 months, aripiprazole 15 mg/day was more effective than placebo in preventing acute relapses of schizophrenia (34% versus 57%), but the clinical relevance of the combined endpoint used to define relapse is unclear. (5) The only double-blind comparison versus another neuroleptic (haloperidol) involved two trials that were pooled for analysis. Haloperidol was provided at a moderate dose (10 mg/day). These trials were designed to demonstrate the superiority of high-dose aripiprazole (30 mg/day), but failed to do so. The proportion of patients who "responded" during an acute episode, based on the least stringent definition, was about 70% in both groups. In both groups, response persisted in approximately three-quarters of patients. (6) Aripiprazole exhibits the adverse effects classically seen with neuroleptics. In clinical trials, daily doses of aripiprazole, ranging from 15 mg to 30 mg, provoked fewer extrapyramidal disorders than haloperidol 10 mg/day. In contrast, there was no difference in the frequency of extrapyramidal disorders with aripiprazole 20 or 30 mg/day and risperidone (6 mg). Aripiprazole has no proven advantage over haloperidol in terms of the risk of tardive dyskinesia. One trial showed no difference between aripiprazole and olanzapine in the risk of diabetes. Weight gain appears to be comparable with aripiprazole and haloperidol. Aripiprazole provoked postural hypotension and neuroleptic malignant syndrome, but the precise risk relative to other neuroleptics has not been documented. Supra-therapeutic doses of aripiprazole cause dose-dependent QT prolongation. (7) Increased mortality was seen in elderly patients treated with aripiprazole. (8) Animal studies have shown retinal degeneration in rats and biliary lithiasis in monkeys. These adverse effects have not been observed in clinical trials, but they have not been specifically assessed in humans. (9) Animal studies raised the possibility of fetal toxicity and teratogenicity. (10) The aripiprazole dose must be either halved or doubled during co-administration with inhibitors or inducers of cytochrome P450 isoenzymes CYP 3A4 and CYP 2D6. (11) In practice, there are too many unanswered questions to recommend aripiprazole for patients with schizophrenia.

Antipsychotic Agents↗

PubMed2006

Aripiprazole for schizophrenia.

BACKGROUND: Treatment of people with schizophrenia using older typical antipsychotic drugs such as haloperidol can be problematic. Many fail to respond to these older antipsychotics and more people experience disabling adverse effects. Aripiprazole is said to be one of a new generation of atypical antipsychotics with good antipsychotic properties and minimal adverse effects. OBJECTIVES: To evaluate the effects of aripiprazole for people with schizophrenia and schizophrenia-like psychoses. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group's Register (September 2005) which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO. We inspected references of all identified studies for further trials. We contacted relevant pharmaceutical companies, the FDA and authors of trials for additional information. SELECTION CRITERIA: All clinical randomised trials comparing aripiprazole with placebo, typical or atypical antipsychotic drugs for schizophrenia and schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For homogenous dichotomous data we calculated random effects, relative risk (RR), 95% confidence intervals (CI) and, where appropriate, numbers needed to treat (NNT) on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (WMD). MAIN RESULTS: Despite the fact that 7110 people participated in fifteen randomised aripiprazole studies, we were unable to extract any usable data on death, service outcomes, general functioning, behaviour, engagement with services, satisfaction with treatment; economic outcomes or cognitive functioning. Study attrition was very large and data reporting poor. Compared with placebo, aripiprazole significantly decreased relapse in both the short and medium term (n=300, 1 RCT, RR 0.66 CI 0.5 to 0.8, NNT 5 CI 4 to 8). It also produced better compliance with study protocol (n=2271, 8 RCTs, RR 0.72 CI 0.5 to 0.97, NNT 26 CI 16 to 239). Aripiprazole may decrease prolactin levels below that expected from placebo (n=305, 1 RCT, RR 0.32 CI 0.1 to 0.8, NNT 14 CI 11 to 50). Compared with typical antipsychotics there were no significant benefits for aripiprazole with regards to global state, mental state, quality of life or leaving the study early. Both groups reported similar rates of adverse effects, with the exception of akathisia (n= 955 RR 0.31 CI 0.2 to 0.6, NNT 20 CI 17 to 32) and the need for antiparkinson medication (n=1854, 4 RCTs, RR 0.45 CI 0.3 to 0.6, NNT 4 CI 3 to 5) which were lower in those receiving aripiprazole. When compared with olanzapine and risperidone, aripiprazole was no better or worse on outcomes of global state and leaving the study early. The rates of adverse effects were also similar, with the exception of less elevation of prolactin (n=301, 1 RCT, RR 0.04 CI 0.02 to 0.1, NNT 2 CI 1 to 2.5) and less prolongation of the average QTc (30 mg/day) (n=200, 1 RCT, WMD -10.0, CI -16.99 to -3.0) compared with risperidone. When compared with standard care (mixed group receiving typical and atypical antipsychotics) one aripiprazole study did have significantly less people not responding to treatment (n=1599, RR 0.70 CI 0.7 to 0.8, NNT 5 CI 4 to 6 ), not satisfied with care (n=1599, RR 0.62 CI 0.6 to 0.7, NNT 4 CI 4 to 5) and less people leaving the study early (n=1599, 1 RCT, RR 0.81 CI 0.7 to 0.9, NNT 13 CI 8 to 39). Results from the five new papers identified from the updated review search, did not significantly alter the main results or conclusions of the original review. AUTHORS' CONCLUSIONS: Aripiprazole may be effective for the treatment of schizophrenia, but it does not differ greatly from typical and atypical antipsychotics with respect to treatment response, efficacy or tolerability. In comparison with typical antipsychotics, aripiprazole may have a lower risk of akathisia, and in comparison to atypical antipsychotics, less risk of raised prolactin and prolongation of the QTc interval. Clearly reported pragmatic short, medium and long term randomised controlled trials should be undertaken to determine its position in everyday clinical practice.

Antipsychotic Agents↗

PubMed2006

Pharmacokinetic variability of aripiprazole and the active metabolite dehydroaripiprazole in psychiatric patients.

Aripiprazole is a new atypical antipsychotic drug with a partial agonist activity at dopamine 2 and serotonin 1A receptors. The metabolism of aripiprazole involves both cytochrome P450 2D6 (CYP2D6) and CYP3A4. This study investigated the pharmacokinetic variability of aripiprazole and the active metabolite dehydroaripiprazole on the basis of 155 drug monitoring samples from psychiatric patients treated with therapeutic doses of aripiprazole (10-30 mg/day). Serum concentrations of drug and metabolite were determined by liquid chromatographic and tandem mass spectrometric detection. Pharmacokinetic variability was expressed as the range in concentration/dose (C/D) ratios, and the effect of sex and occasionally coprescribed CYP2D6 or CYP3A4 inhibitors/inducers was studied. In addition, the dose-concentration relationship and combined interquartile range of concentrations obtained at low dose (10-15 mg/day) and high dose (20-30 mg/day) were described. Individual C/D ratios ranged 37-fold for aripiprazole, 78-fold for dehydroaripiprazole, and 27-fold for the active sum of aripiprazole + dehydroaripiprazole. Median C/D ratios in male and female patients differed by less than 15%, and none of the differences were significant (P > 0.14). Cases of concurrent CYP3A4 inducers/inhibitors were not found, but three patients were coprescribed the potent CYP2D6 inhibitors paroxetine or fluoxetine. No consistent difference in C/D ratio was observed in these three patients compared with the rest of the patients. There was a proportional dose-concentration relationship in the population, and the combined interquartile ranges were 230 to 960 nmol/L for aripiprazole and 330 to 1210 nmol/L for aripiprazole + dehydroaripiprazole. In conclusion, pharmacokinetic variability of aripiprazole is extensive in psychiatric patients but apparently not dependent on dose or sex. The variability of the pharmacologic active sum of aripiprazole + dehydroaripiprazole is 25% to 30% less than aripiprazole, suggesting that variability of aripiprazole is partly determined by metabolism to dehydroaripiprazole.

Adolescent↗

PubMed2003

Aripiprazole for the prevention of relapse in stabilized patients with chronic schizophrenia: a placebo-controlled 26-week study.

BACKGROUND: Aripiprazole is a novel antipsychotic for the management of schizophrenia. This study investigated the efficacy, safety, and tolerability of aripiprazole in preventing relapse in adult chronic schizophrenia patients experiencing ongoing stable symptomatology. METHOD: In this 26-week, randomized, double-blind, placebo-controlled, parallel-group, multi-center study, 310 patients with DSM-IV schizophrenia (mean Positive and Negative Syndrome Scale [PANSS] total score = 82) were randomly assigned to receive a once-daily fixed dose of aripiprazole, 15 mg, or placebo. The primary outcome measure was time to relapse following randomization. Secondary objectives were to assess the efficacy, safety, and tolerability of aripiprazole, 15 mg, compared with placebo, in the study population. The study was conducted between Dec. 21, 2000, and Aug. 20, 2001. RESULTS: The time to relapse following randomization was significantly (p < .001) longer for aripiprazole compared with placebo. More patients relapsed with placebo (N = 85; 57%) than aripiprazole (N = 50; 34%); the relative risk of relapse for the aripiprazole group was 0.59 (p < .001). Aripiprazole was significantly superior to placebo from baseline to endpoint in PANSS total, PANSS positive, PANSS-derived Brief Psychiatric Rating Scale, and Clinical Global Impressions-Severity of Illness scale (CGI-S) scores and demonstrated significantly better mean Clinical Global Impressions-Global Improvement scale scores (p < or = .01 for all comparisons except CGI-S: .01 < p < or = .05). Aripiprazole was well tolerated, with no evidence of marked sedation and no evidence of hyperprolactinemia or prolonged heart rate-corrected QT interval (QTc). Extrapyramidal symptoms were comparable in the aripiprazole and placebo groups. Modest mean weight loss at endpoint was evident in both groups. CONCLUSION: Aripiprazole, 15 mg once daily, is an effective, well-tolerated treatment for prevention of relapse in patients with chronic, stable schizophrenia.

Adult↗

PubMed2006

A randomized, double-blind, placebo-controlled 26-week trial of aripiprazole in recently manic patients with bipolar I disorder.

OBJECTIVE: To investigate the safety and efficacy of aripiprazole in preventing relapse of a mood episode in recently manic- or mixed-episode patients with bipolar I disorder stabilized on aripiprazole. METHOD: This randomized, double-blind, parallel-group, placebo-controlled, multicenter study enrolled patients from 76 centers in 3 countries (Argentina, Mexico, United States) from March 2000 to June 2003. Bipolar I disorder (DSM-IV) patients who had recently been hospitalized and treated for a manic or mixed episode entered an open-label stabilization phase (aripiprazole monotherapy: 15 or 30 mg/day, 6-18 weeks). After meeting stabilization criteria (Young Mania Rating Scale score of < or = 10 and Montgomery-Asberg Depression Rating Scale score of < or = 13 for 6 consecutive weeks), 161 patients were randomly assigned to aripiprazole or placebo for the 26-week, double-blind phase. The primary endpoint was time to relapse for a manic, mixed, or depressive episode (defined by discontinuation caused by lack of efficacy). RESULTS: Aripiprazole was superior to placebo in delaying the time to relapse (p = .020). Aripiprazole-treated patients had significantly fewer relapses (25%) than placebo patients (43%; p = .013). Aripiprazole was superior to placebo in delaying the time to manic relapse (p = .01); however, no significant differences were observed in time to depressive relapse (p = .68). Weight gain (> or = 7% increase) occurred in 7 (13%) aripiprazole-treated and 0 placebo-treated patients. Adverse events (> or = 5% incidence and twice that of placebo) reported by aripiprazole-treated patients were akathisia, pain in the extremities, tremor, and vaginitis. CONCLUSIONS: Aripiprazole, 15 or 30 mg/day, was superior to placebo in maintaining efficacy in patients with bipolar I disorder with a recent manic or mixed episode who were stabilized and maintained on aripiprazole treatment for 6 weeks, as shown by a longer time to relapse.

Adult↗

PubMed2004

Aripiprazole for schizophrenia.

BACKGROUND: Treatment of people with schizophrenia using older typical antipsychotic drugs such as haloperidol can be problematic. Many fail to respond and more experience disabling adverse effects. Aripiprazole is said to be one of a new generation of atypical antipsychotics with good antipsychotic properties and minimal adverse effects. OBJECTIVES: To evaluate the effects of aripiprazole for people with schizophrenia and schizophrenia-like psychoses. SEARCH STRATEGY: The reviewers searched the Cochrane Schizophrenia Group's Register (May 2003) which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO. References of all identified studies were inspected for further trials. The authors contacted relevant pharmaceutical companies, the FDA and authors of trials for additional information. SELECTION CRITERIA: All clinical randomised trials comparing aripiprazole with placebo, typical or atypical antipsychotic drugs for schizophrenia and schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For homogenous dichotomous data we calculated random effects, relative risk (RR), 95% confidence intervals (CI) and, where appropriate, numbers needed to treat (NNT) on an intention-to-treat basis. For continuous data, we calculated weighted mean differences (WMD). MAIN RESULTS: Despite the fact that 4125 people participated in ten randomised aripiprazole studies, we were unable to extract any usable data on death, service outcomes, general functioning, behaviour, engagement with services, satisfaction with treatment; economic outcomes or cognitive functioning. Study attrition was very large and data reporting poor. Compared with placebo, aripiprazole significantly decreased relapse in both the short and medium term (n=300, 1 RCT, RR 0.66 CI 0.53 to 0.81, NNT 5 CI 4 to 8). It also produced better compliance with study protocol (n=1348, 5 RCTs, RR 0.66 CI 0.49 to 0.88, NNT 15 CI 10 to 41). Aripiprazole may decrease prolactin levels below that expected from placebo (n=305, 1 RCT, RR 0.32 CI 0.13 to 0.81, NNT 14 CI 11 to 50). Compared with typical antipsychotics there were no significant benefits for aripiprazole with regards to global state, mental state, quality of life or leaving the study early. Both groups reported similar rates of adverse effects, including akathisia (RR 0.44 CI 0.17 to 1.12) and general extrapyramidal effects (RR 0.53 CI 0.18 to 1.53). Aripiprazole did however cause more insomnia than perphenazine (n=300, 1 RCT, RR 2.23 CI 1.57 to 3.18, NNH 4 CI 3 to 9) and less need for antiparkinson drugs than 10-20mg/day haloperidol (n=1854, 4 RCTs, RR 0.45 CI 0.33 to 0.60, NNT 4 CI 3 to 5). When compared with olanzapine and risperidone, aripiprazole was no better or worse on outcomes of global state and leaving the study early. The rates of adverse effects were also similar, with the exception of less elevation of prolactin (n=301, 1 RCT, RR 0.04 CI 0.02 to 0.08, NNT 2) and less prolongation of the average QTc (30mg/day) (n=200, 1 RCT, WMD -10.0, CI -16.99 to -3.01) compared with risperidone. REVIEWERS' CONCLUSIONS: Aripiprazole may be effective for the treatment of schizophrenia, but it is not much different from typical antipsychotics and atypical antipsychotics with respect to treatment response, efficacy or tolerability. In comparison with typical antipsychotics, aripiprazole may have a higher risk of insomnia, but in comparison to atypical antipsychotics, less risk of raised prolactin and prolongation of the QTc interval. Clearly reported pragmatic short, medium and long term randomised controlled trials should be carried out to determine its position in everyday clinical practice.

Antipsychotic Agents↗

PubMed2006

Aripiprazole as a potential pharmacotherapy for stimulant dependence: human laboratory studies with d-amphetamine.

Amphetamine and cocaine dependence present significant public health concerns, yet no broadly effective pharmacotherapy for stimulant dependence has been developed. Two human laboratory studies are reviewed that tested the ability of aripiprazole, a novel antipsychotic with partial agonist activity at D2 dopamine receptors, to alter the behavioral effects of stimulants using d-amphetamine as a model agent. In each of these experiments, volunteers learned to discriminate 15 mg d-amphetamine (i.e., > or =80% drug-appropriate responding over 4 consecutive sessions). The effects of a range of doses of d-amphetamine (0, 2.5, 5, 10, and 15 mg) were then tested alone and following pretreatment with aripiprazole (20 mg in Experiment 1; 10 mg in Experiment 2). In Experiment 1, aripiprazole (20 mg) attenuated the discriminative stimulus and many of the subject-rated effects of amphetamine. Aripiprazole alone produced performance decrements. To determine whether a lower dose of aripiprazole would also attenuate the behavioral effects of d-amphetamine without impairing performance, Experiment 2 was conducted. Aripiprazole (10 mg) failed to alter the discriminative-stimulus effects but attenuated some of the subject-rated effects of d-amphetamine. This dose of aripiprazole did not impair performance. The results of these experiments indicate that aripiprazole may have clinical utility in treating stimulant dependence. Future human laboratory research should better model the clinical use of aripiprazole by examining the effects of chronic aripiprazole combined with either methamphetamine or cocaine in dependent individuals. A large-scale clinical trial is also needed to evaluate the efficacy of aripiprazole for the treatment of stimulant dependence.

Adult↗

PubMed2002

Aripiprazole, a novel antipsychotic, is a high-affinity partial agonist at human dopamine D2 receptors.

Aripiprazole is the first next-generation atypical antipsychotic with a mechanism of action that differs from currently marketed typical and atypical antipsychotics. Aripiprazole displays properties of an agonist and antagonist in animal models of dopaminergic hypoactivity and hyperactivity, respectively. This study examined the interactions of aripiprazole with a single population of human D2 receptors to clarify further its pharmacologic properties. In membranes prepared from Chinese hamster ovary cells that express recombinant D2L receptors, aripiprazole bound with high affinity to both the G protein-coupled and uncoupled states of receptors. Aripiprazole potently activated D2 receptor-mediated inhibition of cAMP accumulation. Partial receptor inactivation using the alkylating agent N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) significantly reduced the maximum effect of aripiprazole on inhibition of cAMP accumulation. This effect was seen with concentrations of EEDQ that did not alter the maximal inhibitory effect of dopamine. Consistent with the expected effects of a partial agonist, increasing concentrations of aripiprazole blocked the action of dopamine with maximal blockade equal to the agonist effect of aripiprazole alone. The efficacy of aripiprazole relative to that of dopamine varied from 25% in cells that lacked spare receptors for dopamine to 90% in cells with receptor reserve. These results, together with previous studies demonstrating partial agonist activity at serotonin 5-hydroxytryptamine (5-HT)1A receptors and antagonist activity at 5-HT2A receptors, support the identification of aripiprazole as a dopamine-serotonin system stabilizer. The receptor activity profile may underlie the unique activity of aripiprazole in animals and its antipsychotic activity in humans.

1-Methyl-3-isobutylxanthine↗

PubMed2006

Relapse rates in patients with schizophrenia receiving aripiprazole in comparison with other atypical antipsychotics.

OBJECTIVE: Aripiprazole is the first of a new generation of antipsychotics that possesses a unique mechanism of action as a partial dopamine agonist. After the release of aripiprazole, case reports appeared conveying an acute psychosis/agitation reaction occurring after the initiation of treatment, most specifically after patients were switched from a previous antipsychotic to aripiprazole. The primary objective of this study was to compare relapse rates among patients with schizophrenia who were switched to aripiprazole with those who switched to a second-generation antipsychotic (SGA) from another antipsychotic. METHOD: The design was a retrospective cohort study based on Kansas Medicaid enrollees with an ICD-9-CM diagnosis code for schizophrenia during calendar year 2002 who switched antipsychotic agents. Six-month psychiatric relapse rates, defined as hospitalization for a psychiatric event, were compared between those subjects who switched to aripiprazole and those who switched to another SGA. Time to relapse was modeled using Cox proportional hazards, adjusting for demographic characteristics, major comorbid conditions, and prior psychiatric-related health care use. RESULTS: Four hundred forty-four aripiprazole and 521 SGA switchers were comparable with respect to gender, race, comorbidities, and health care utilization, though the aripiprazole group was 4.5 years younger. Twenty percent of aripiprazole patients and 19.4% of patients receiving SGAs were hospitalized 6 months after being switched (relative risk = 0.92; 95% CI = 0.67 to 1.26). Mean times to psychiatric hospitalization for the aripiprazole and SGA groups were 65.7 and 73.8 days, respectively (p > .05). Factors associated with hospitalization were prior psychiatric hospitalizations and comorbid depression, substance abuse, and neurotic, personality, and nonpsychotic mental disorders. CONCLUSION: Our study found that rates of relapse and time to relapse with aripiprazole were comparable to other SGAs during a 6-month period. Thus, aripiprazole appears to be an appropriate first-line agent along with the other SGAs.

Adolescent↗

PubMed2003

Aripiprazole, an antipsychotic with a novel mechanism of action, and risperidone vs placebo in patients with schizophrenia and schizoaffective disorder.

BACKGROUND: Aripiprazole is a dopamine D2 receptor partial agonist with partial agonist activity at serotonin 5HT1A receptors and antagonist activity at 5HT2A receptors. This multicenter trial examined the efficacy, safety, and tolerability of aripiprazole in patients with acute exacerbation of schizophrenia or schizoaffective disorder. METHODS: In this 4-week double-blind study, 404 patients were randomized to 20 mg/d (n = 101) or 30 mg/d (n = 101) of aripiprazole, placebo (n = 103), or 6 mg/d of risperidone (n = 99). Efficacy assessments included Positive and Negative Syndrome Scale (PANSS) scores and Clinical Global Impression scores. Safety and tolerability evaluations included extrapyramidal symptoms and effects on weight, prolactin, and corrected QT (QTc) interval. RESULTS: Aripiprazole (20 and 30 mg/d) and risperidone (6 mg/d) were significantly better than placebo on all efficacy measures. Separation from placebo occurred at week 1 for PANSS total and positive scores with aripiprazole and risperidone and for PANSS negative scores with aripiprazole. There were no significant differences between aripiprazole and placebo in mean change from baseline in the extrapyramidal symptom rating scales. Mean prolactin levels decreased with aripiprazole but significantly increased 5-fold with risperidone. Mean change in QTc interval did not differ significantly from placebo with any active treatment group. Aripiprazole and risperidone groups showed a similar low incidence of clinically significant weight gain. CONCLUSIONS: Aripiprazole is effective, safe, and well tolerated for the positive and negative symptoms in schizophrenia and schizoaffective disorder. It is the first non-D2 receptor antagonist with clear antipsychotic effects and represents a novel treatment development for psychotic disorders.

Adult↗

PubMed2003

Aripiprazole in the treatment of schizophrenia: safety and tolerability in short-term, placebo-controlled trials.

Aripiprazole is a novel antipsychotic with a unique mechanism of action. Presented here is a pooled analysis of safety and tolerability data from all completed short-term, placebo-controlled trials in schizophrenia from the aripiprazole clinical development program. Data were analyzed from five 4- to 6-week double-blind multicenter studies of patients hospitalized with acute relapse of schizophrenia or schizoaffective disorder randomized to aripiprazole (n=932), placebo (n=416), or haloperidol (n=201). Daily aripiprazole doses ranged from 2 to 30 mg. Safety assessments included adverse event (AE) reports, EPS scales, ECGs, weight, and prolactin, glucose and cholesterol levels. Aripiprazole was well tolerated, with similar AE incidence rates to placebo, and lower rates than haloperidol for akathisia, extrapyramidal syndrome and somnolence. Objective EPS assessments demonstrated no significant differences between aripiprazole and placebo on Simpson-Angus Scale (SAS) scores, no dose-dependent effects on Barnes Akathisia scores, and significant reductions in Abnormal Involuntary Movement Scale (AIMS) scores from baseline vs. placebo (p</=0.01). Haloperidol showed increased SAS and Barnes Akathisia scores over placebo (p</=0.01). There was minimal mean weight change with aripiprazole (+0.71 kg) and haloperidol (+0.56 kg), and a lack of QT(c) prolongation. Serum prolactin increased with haloperidol, but not aripiprazole. In conclusion, aripiprazole shows a favorable safety and tolerability profile with low potential for EPS, weight gain, prolactin elevation, QT(c) prolongation, and sedation. Aripiprazole's safety profile may offer benefits in schizophrenia treatment.

Acute Disease↗

PubMed2006

Aripiprazole has functionally selective actions at dopamine D2 receptor-mediated signaling pathways.

Aripiprazole is a unique atypical antipsychotic drug with an excellent side-effect profile presumed, in part, to be due to lack of typical D(2) dopamine receptor antagonist properties. Whether aripiprazole is a typical D(2) partial agonist, or a functionally selective D(2) ligand, remains controversial (eg D(2)-mediated inhibition of adenylate cyclase is system dependent; aripiprazole antagonizes D(2) receptor-mediated G-protein-coupled inwardly rectifying potassium channels and guanosine triphosphate nucleotide (GTP)gammaS coupling). The current study examined the D(2L) receptor binding properties of aripiprazole, as well as the effects of the drug on three downstream D(2) receptor-mediated functional effectors: mitogen-activated protein kinase (MAPK) phosphorylation, potentiation of arachidonic acid (AA) release, and D(2) receptor internalization. Unlike quinpirole (a full D(2) agonist) or (-)3PPP (S(-)-3-(3-hydroxyphenyl)-N-propylpiperidine hydrochloride, a D(2) partial agonist), the apparent D(2) affinity of aripiprazole was not decreased significantly by GTP. Moreover, full or partial agonists are expected to have Hill slopes <1.0, yet that of aripiprazole was significantly >1.0. Whereas aripiprazole partially activated both the MAPK and AA pathways, its potency vs MAPK phosphorylation was much lower relative to potencies in assays either of AA release or inhibition of cyclic adenosine 3',5'-cyclic monophosphate accumulation. In addition, unlike typical agonists, neither aripiprazole nor (-)3PPP produced significant internalization of the D(2L) receptor. These data are clear evidence that aripiprazole affects D(2L)-mediated signaling pathways in a differential manner. The results are consistent with the hypothesis that aripiprazole is a functionally selective D(2) ligand rather than a simple partial agonist. Such data may be useful in understanding the novel clinical actions of this drug.

Analysis of Variance↗

PubMed2005

Aripiprazole: an overview of a novel antipsychotic.

Aripiprazole exhibits high affinity for dopamine D2 and D3, serotonin 5-HT1A and 5-HT2A receptors, moderate affinity for dopamine D4, serotonin 5-HT2C and 5-HT7, alpha1-adrenergic and histamine H1 receptors. The mean elimination half-lives are about 75 hours and 94 hours for aripiprazole and dehydroaripiprazole, respectively. Steady-state concentrations are attained within 14 days of dosing for both active moieties. At least 1 to 2 weeks, and sometimes up to 4 weeks, may pass before aripiprazole reaches its full effect. The efficacy of aripiprazole was investigated in the treatment of schizophrenia, in the treatment of acute manic episode associated with Bipolar I Disorder, and in the treatment of psychosis associated with Alzheimer's dementia. Aripiprazole has demonstrated superiority to placebo in clinical studies of the treatment of both schizophrenia and acute bipolar mania. Aripiprazole has been evaluated for safety in 5592 patients who participated in multiple dose, premarketing trials in schizophrenia, bipolar mania, and dementia of the Alzheimer's type. The recommended starting and target dose for aripiprazole is 10 or 15 mg/day administered on a once-a-day schedule without regard to meals. Aripiprazole has been systematically evaluated and shown to be effective in a dose range of 10 to 30 mg/day. Dosage increases should not be made before 2 weeks of continuous therapy, the time needed to achieve steady state. At least 1 to 2 weeks, and sometimes up to 4 weeks, may pass before aripiprazole reaches its full effect. In this presentation was given an overview of novel antipsychotic aripiprazole.

Alzheimer Disease↗

PubMed2006

Aripiprazole in the treatment of acute manic or mixed episodes in patients with bipolar I disorder: a 3-week placebo-controlled study.

This study compares the efficacy, safety, and tolerability of a partial dopamine agonist, aripiprazole, with placebo in the treatment of patients with bipolar I disorder experiencing an acute manic or mixed episode. In total, 272 hospitalized patients were randomized to aripiprazole 30 mg/day or placebo in this 3-week, double-blind, placebo-controlled trial. Dosing could be reduced to 15 mg/day for tolerability and, subsequently, increased to 30 mg/day based on clinical response. Primary efficacy measure was mean change from baseline to endpoint in Young Mania Rating Scale (YMRS) total score; response was defined as > or = 50% decrease from baseline YMRS score. Aripiprazole-treated patients demonstrated significantly greater improvement from baseline to endpoint in mean YMRS total scores compared with placebo-treated patients as early as Day 4 and sustained through Week 3. A significantly higher response rate was observed in aripiprazole-treated patients (53% vs. 32% at endpoint). Aripiprazole produced significantly greater improvements from baseline on other efficacy assessments compared with placebo, including Clinical Global Impression - Bipolar Version Severity and Improvement scores. The 30 mg/day dose was maintained by 85% of aripiprazole-treated patients. Incidence of discontinuations due to adverse events was similar for aripiprazole (8.8%) and placebo (7.5%). Aripiprazole treatment resulted in no significant difference from placebo in change in mean body weight and was not associated with elevated serum prolactin or QTc prolongation. In conclusion, aripiprazole demonstrated superior efficacy to placebo in the treatment of patients with bipolar I disorder presenting with acute manic or mixed episodes, and exhibited a favourable safety and tolerability profile.

Adult↗

PubMed2006

A case series of patients with Tourette's syndrome in the United Kingdom treated with aripiprazole.

OBJECTIVE: These cases illustrate that a new neuroleptic, aripiprazole, may be an effective treatment for the motor and vocal tics of Tourette Syndrome (TS), even in younger people. METHOD: A case series of 11 consecutive patients with TS (age range 7-50 years; M = 7) who were felt to require neuroleptic medication, were treated with aripiprazole, the majority of whom had been refractory to treatment with other neuroleptics, and in one case, Habit Reversal Training as well. RESULTS: Ten out of the 11 patients who were treated with aripiprazole improved, although to differing degrees. The only individual who showed no response was treated for only 1 month with a low dose (5 mg). Eight of the patients had been treated with many typical and atypical neuroleptics without success, and which had also given unacceptable side effects, resulting in them being unable to function at times. One was also unresponsive to previous Habit Reversal Training. The response to aripiprazole was dramatic and quick in five patients; in the rest (5/10) the response was less dramatic. In the majority of patients, response was sustained. The successful aripiprazole doses were between 10-20 mg daily. Side effects were mild and transient. This, to the best of our knowledge, is the first case series of patients with TS successfully treated with aripiprazole in the United Kingdom, and one of the few to date in the English Scientific literature. Our patients are also the first cases reported, in which the patients were assessed and whose improvement was monitored using standardised schedules and rating scales, such as the Yale Global Tic Severity Rating Scale and MOVES. Aripiprazole was licensed for use in patients with schizophrenia in the European Union in June 2004. We discuss possible reasons for these dramatic and idiosyncratic responses to aripiprazole. CONCLUSION: We suggest that aripiprazole may well be useful for individuals with TS as response to it is often quick, dramatic, sustained and with few generally mild and transient side effects.

Adolescent↗

PubMed2003

Aripiprazole (OPC-14597) fully substitutes for the 5-HT1A receptor agonist LY293284 in the drug discrimination assay in rats.

RATIONALE: Aripiprazole (OPC-14597) is a novel atypical antipsychotic drug with a low incidence of side effects. The therapeutic action of aripiprazole has been attributed to its unique agonist/antagonist effects at D(2) dopamine receptors; however, aripiprazole also has significant in vitro affinity at 5-HT(1A) receptors. OBJECTIVES: The 5-HT(1A) agonist property of aripiprazole has so far not been evaluated in any in vivo assay. METHODS: Thirteen male Sprague Dawley rats trained to discriminate the 5-HT(1A) agonist LY 293284 (75 nmol/kg) from saline, using a fixed ratio (FR) 50 schedule of food-reinforcement in a two-lever operant-conditioning task, were used to evaluate the behavioral effect of aripiprazole at 5-HT(1A) receptors. RESULTS: Aripiprazole fully mimicked LY 293284 in a drug-discrimination assay with an ED(50) of 1.39 micromol/kg (0.62 mg/kg). In combination tests, aripiprazole did not block the LY 293284 cue but at 8.92 micromol/kg (4 mg/kg) significantly reduced the response rate by lowering the threshold for induction of the 5-HT syndrome produced by the training dose of LY 293284. Moreover, the selective 5HT(1A) receptor antagonist WAY 100635 was able to block the substitution of aripiprazole in LY-293284 trained rats. CONCLUSION: Although the efficacy of aripiprazole against the positive symptoms of schizophrenia may be related to its dopamine receptor interactions, it seems possible that its atypical profile may derive, at least in part, from its 5-HT(1A) agonist effect, rather than from unusual D(2) receptor properties.

Animals↗