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Original Articles

Efficacy and acceptability of three prolactin-sparing antipsychotics in patient with schizophrenia: a network meta-analysis

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Pages 369-378 | Received 22 Jul 2019, Accepted 29 Aug 2019, Published online: 27 Sep 2019

ABSTRACT

Background: The present study aimed to systematically evaluate three prolactin-sparing antipsychotics for treating schizophrenia.

Methods: We performed a meta-analysis of three prolactin-sparing antipsychotics in patients with schizophrenia. Endpoints of interest were the Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS), Clinical Global Impressions-Severity (CGI-S) and acceptability (all cause discontinuation).

Results: A total of 12 trials (2,723 patients) and three drugs (aripiprazole, quetiapine, and ziprasidone) were included. On the PANSS scale, aripiprazole (mean difference [MD]: −6.98, 95% CrI: −12.35, −1.38) was statistically more effective than placebo. When assessed by BPRS, aripiprazole (MD: −9.01, 95% CrI: −15.81, −3.12), quetiapine (MD: −7.13, 95% CrI: −9.78, −4.29) and ziprasidone (MD: −4.97, 95% CrI: 9.96, −0.21) had greater efficacy, when compared to placebo. Regarding CGI-S, quetiapine (MD: −0.55, 95% CrI: −0.82, −0.25) was significantly superior to placebo. In terms of acceptability, aripiprazole (OR: 0.54, 95% CrI: 0.41, 0.73), quetiapine (OR: 0.49, 95% CrI: 0.36, 0.68) and ziprasidone (OR: 0.68, 95% CrI: 0.48, 0.96) were more acceptable than placebo. The benefit risk analysis revealed that quetiapine has the best efficacy and acceptability profile among the three prolactin-sparing antipsychotics.

Conclusions: Quetiapine may offer an optimal benefit-risk balance when a prolactin-sparing antipsychotic is indicated.

Introduction

Schizophrenia is a severe psychiatric disorder that originates from the dysfunction of dopaminergic neurotransmission and disturbances in synaptic function caused by genetic or environmental factors, or both [Citation1]. Long-term maintenance treatment with antipsychotic drugs remains as the main treatment approach, and approximately 20 antipsychotic medications are presently available [Citation2]. These drugs have the capability to acutely or chronically block dopaminergic D2 receptors, to a certain extent [Citation3]. Since the inhibitory action of dopamine is responsible for physiological prolactin secretion, the chronic blockade of the dopamine D2 receptor could lead to the elevation of prolactin in blood serum through the disruption of the tonic dopamine inhibition of prolactin secretion, which is medically termed as hyperprolactinemia [Citation4,Citation5].

Antipsychotics differ in propensity to induce and sustain hyperprolactinemia due to the difference in receptor binding profiles and systemic actions [Citation6]. Antipsychotic-induced hyperprolactinemia could occur in 70% of patients with schizophrenia, depending on the medication used [Citation7]. Furthermore, prolactin has over 300 separate biological activities [Citation8], and it is mainly responsive for the lactation in females, as well as the regulation of gonadotropic and reproductive hormones in both women and men.

The sustained elevation of prolactin above the upper limits of normal could lead to galactorrhea, breast enlargement, hypogonadism and sexual dysfunction [Citation9–11]. Chronic hyperprolactinemia can also contribute to osteopenia and osteoporosis [Citation12]. cardiovascular disease, autoimmune activation [Citation13], and breast cancer [Citation14]. There are several strategies for the management of antipsychotic-induced hyperprolactinemia [Citation15], such as discontinuing the drug or switching to other antipsychotics, and adding a dopamine agonist to the treatment regime. However, most guidelines caution these treatment approach, because it might exacerbate psychosis in patients with schizophrenia [Citation16]. Switching from prolactin-elevating to prolactin-sparing agents may provide an optimal solution for long-term antipsychotic therapy with relatively less risk of hyperprolactinemia and associated morbidity [Citation15,Citation17–19].

Prolactin-sparing agents are antipsychotics that might lead to a slight or transient increase in prolactin level within the upper limit of normal, and lower frequencies of hyperprolactinemia-associated side effects [Citation20–22]. There is a general consensus that aripiprazole, quetiapine and ziprasidone are less likely to increase prolactin levels (prolactin-sparing) [Citation15,Citation20,Citation22,Citation23]. Although these prolactin-sparing antipsychotics have been evaluated in many clinical trials, there are still varying conclusions regarding the efficacy and acceptability. In order to provide useful evidence for clinical practice, it is of great importance to generate clear hierarchies for the efficacy and acceptability of these drugs. Therefore, a network meta-analysis was performed to comprehensively compare and rank the comparative performance of three prolactin-sparing antipsychotics for patients with schizophrenia.

Methods

Search strategy

The present systematic review and network meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline for Network Meta-Analyses [Citation24]. A systematic review of articles published up to the 1st of March 2019 in Medline (via PubMed) and Web of Science was conducted. The following keywords were used: “schizophrenia”, “aripiprazole”, “quetiapine”, “ziprasidone”, and “randomized controlled trial”. The search was limited to randomized controlled trials (RCTs) published in the English language. Full-text articles were chosen after screening the abstracts. The references obtained from retrieved publications were manually searched to identify potential studies.

Inclusion criteria and study selection

Studies that met the inclusion criteria were included: (i) Patients: Schizophrenia, schizoaffective disorder, or schizophreniform disorder as defined by any diagnostic criteria. (ii) Intervention: Acute treatment (4–12 weeks) with one of three prolactin-sparing antipsychotics (15–30 mg/day of aripiprazole, 400–1,000 mg/day of quetiapine, and 120–200 mg/day of ziprasidone) [Citation25] as monotherapies, including both flexible and fixed-dose studies. (iii) Comparator: Placebo or another agent of the five mentioned above. (iv) Outcomes: Primary outcomes were the mean change in the total score of the Positive and Negative Syndrome Scale (PANSS), Brief Psychiatric Rating Scale (BPRS), and Clinical Global Impressions-Severity (CGI-S) score from baseline to endpoint. The secondary outcome was acceptability (the proportion of patients who left the study early for any reason). (v) Study design: Randomized controlled trial (RCT).

The exclusion criteria were as follows: (a) studies without a designated intervention/comparator arm; (b) studies in which anti-Parkinson drugs were given prophylactically; (c) long-term studies without data for a 4–12-week period; (d) studies not reported in the English language. Two authors independently reviewed all retrieved studies according to the inclusion and exclusion criteria. Any inconsistencies were resolved by discussion or arbitrated by a third senior author.

Data extraction

Two researchers independently reviewed the full text to extract information using a structured data abstraction form. The information included the study design, patient characteristics, follow-up duration, treatment protocols, outcomes, etc. The original articles were double-checked when inconsistencies were found. Any disagreement regarding the data extraction and quality assessment was determined by a third senior investigator. Two individuals within the reviewing team independently reviewed the references and abstracts retrieved by the search, assessed the completeness of the data abstraction, and confirmed the quality rating. A structured data abstraction form was used to ensure the consistency of the appraisal for each study. The investigators were contacted and inquired to obtain data to supplement the incomplete reporting of original articles.

Risk of bias assessment

Two review authors assessed the risk of bias of the included studies using the methods recommended by the Cochrane Collaboration for the following items: random sequence generation, allocation concealment, blinding, incomplete outcome data, and selective outcome reporting [Citation26]. A summary of findings tables was created for every rated outcome following the Cochrane-compliant rules. Disagreements were initially resolved by discussion and consulted with a third senior author for arbitration.

Statistical analysis

The network meta-analysis for PANSS, BPRS, CGI-S and acceptability, and multicriteria benefit-risk analysis [Citation27] were performed. All data were comprehensively analyzed using the ADDIS software [Citation28,Citation29] (version 1.16, https://drugis.org/software/addis1/addis1.16), based on the Bayesian framework. Random effect and consistency models were used with the ADDIS parameter (number of chains, 4; tuning iterations, 20,000; simulation iterations, 50,000; thinning interval, 10; inference samples, 10,000; variance scaling factor, 2.5). Convergence was assessed using the Brooks-Gelman-Rubin method, with the potential scale reduction factor (PSRF) as an indicator. A PSRF close to 1 indicates that an approximate convergence has been reached, while a PSRF of <1.2 was considered acceptable. Inconsistencies between the direct effect and indirect effect was assessed by node-splitting analysis.

Results

Characteristics of the included studies

The literature search identified a total of 1,436 studies. Based on the inclusion and exclusion criteria, 12 RCTs [Citation30–41] were eligible for inclusion for the present study (), which included a total of 2,723 patients with schizophrenia. Furthermore, the efficacy (PANSS, BPRS and CGI-S) and acceptability of the three prolactin-sparing antipsychotics (aripiprazole, quetiapine and ziprasidone) were analyzed. The earliest study was conducted in 1997, while the latest study was conducted in 2017. In general, the age of onset ranged within 13–30 years old, and the age of these patients ranged within 15–42 years old. Males accounted for more than 50% of the subjects in the included trials (). In terms of study quality, 10 (83.3%) trials were rated as low risk of bias, while two (16.7%) trials were rated as unclear risk of blinding of participants and personnel, and blinding of outcome assessment (sFigure 1 and sFigure 2). The network graphical structure displayed the available direct comparisons of the network of trials for efficacy and safety (sFigure 3).

Figure 1. Flowchart of the literature search and study selection.

Figure 1. Flowchart of the literature search and study selection.

Table 1. Baseline characteristics of the included studies.

Network meta-analysis of efficacy

A total of nine articles provided raw PNASS data (Figure S3-A), and the overall effects revealed that aripiprazole (MD: −6.98, 95% CrI: −12.35, −1.38) was significantly more effective than placebo (). Furthermore, the probabilities of rank 1 plot for PANSS were as follows: 47% for aripiprazole, 44% for quetiapine, 9% for ziprasidone, and 0 for placebo. Among these interventions, rank 1 was the best, while rank 4 was the worst (sTable 1).

Table 2. Network meta-analysis for PANSS and BPRS.

A total of seven literatures reported the BPRS (Figure S3-B). The results demonstrated that aripiprazole (MD: −9.01, 95% CrI: −15.81, −3.12), quetiapine (MD: −7.13, 95% CrI: −9.78, −4.29) and ziprasidone (MD: −4.97, 95% CrI: 9.96, −0.21) have greater efficacy, when compared to placebo (). The probabilities of aripiprazole, quetiapine, ziprasidone and placebo, based on the BPRS to be the best intervention, were 73%, 24%, 3% and 0%, respectively (sTable 1).

A total of 10 studies reported the CGI-S (Figure S3-C). The present overall analysis indicated that quetiapine (MD: −0.55, 95% CrI: −0.82, −0.25) was significantly superior to placebo (). The probabilities of aripiprazole, quetiapine, ziprasidone and placebo, based on the CGI-S to be the best intervention, were 8%, 79%, 13% and 0%, respectively (sTable 1).

Table 3. Network meta-analysis for acceptability and tolerability.

Network meta-analysis of acceptability

A total of 12 studies were analyzed for acceptability (Figure S3-D), and the pooled estimates revealed that aripiprazole (OR: 0.54, 95% CrI: 0.41, 0.73), quetiapine (OR: 0.49, 95% CrI: 0.36, 0.68) and ziprasidone (OR: 0.68, 95% CrI: 0.48, 0.96) have statistically lesser patients who discontinued treatment due to any reason, when compared to placebo (). The probabilities of the five prolactin-sparing second-generation antipsychotics, based on acceptability to be best intervention, were 31% for aripiprazole, 66% for quetiapine, 3% for ziprasidone, and 0% for placebo (sTable 1).

Overall rank according to the risk-benefit profile

The multicriteria benefit-risk analysis, with PANSS, BPRS and CGI-S as benefit and acceptability as risk, were generally consistent with the results of the network meta-analysis. Aripiprazole (MD: −6.93, 95%CI: −12.24, −1.62) and quetiapine (MD: −0.55, 95%CI: −0.83, −0.27) could significantly alleviate the clinical symptoms of schizophrenia in terms of PANSS and CGI-S, respectively. Furthermore, aripiprazole (MD: −9.14, 95%CI: −15.47, −2.82), quetiapine (MD: −7.10, 95%CI: −9.81, −4.40) and ziprasidone (MD: −5.03, 95%CI: −9.82, −0.23) could significantly improve the clinical symptoms of schizophrenia in terms of BPRS. Moreover, aripiprazole (OR: 0.54, 95% CrI: 0.41, 0.72), quetiapine (OR: 0.49, 95% CrI: 0.35, 0.69) and ziprasidone (OR: 0.68, 95% CrI: 0.48, 0.95) were acceptable, when compared to placebo (). Considering the risk–benefit profile, the overall rank of these three prolactin-sparing antipsychotics were quetiapine, aripiprazole and ziprasidone ().

Figure 2. The overall benefit-risk rank to be the best treatment in terms of PANSS, CGI-S, BPRS, acceptability. Rank 1 is the best; rank n is the worst.

Figure 2. The overall benefit-risk rank to be the best treatment in terms of PANSS, CGI-S, BPRS, acceptability. Rank 1 is the best; rank n is the worst.

Table 4. Summary for the benefit risk analysis.

Consistency and convergence analysis

Regarding the node-splitting analysis of inconsistency, no inconsistency factors were identified (P-value >0.05 in all analyses), indicating the robustness of the present network. Furthermore, all PSRF values for PANSS, BPRS, CGI-S, and acceptability were <1.02, which demonstrate that the present analysis achieved good convergence.

Discussion

The present study provides not only evidence-based hierarchies, but also a benefit risk analysis for the efficacy and acceptability of these three prolactin-sparing antipsychotics for patients with schizophrenia. In addition, flexible and fixed dose monotherapy were included for these three prolactin-sparing antipsychotics, which are similar to a previous network meta-analysis of 15 antipsychotic drugs in schizophrenia [Citation25], and the target doses were up to the maximum doses for fixed-dose studies, based on the international consensus [Citation42]. Although these three antipsychotics are known as prolactin-sparing potency drugs, these could also induce hyperprolactinemia and side effects potentially related to hyperprolactinemia [Citation43]. Thus, monitoring prolactin levels among patients receiving prolactin-sparing antipsychotics is recommended [Citation22].

Although aripiprazole has high affinity for the D2 receptor, it has low rates of hyperprolactinemia similar to clozapine (<5%), which is presumably due to the partial agonist at the D2 receptor [Citation44–46]. Both short- and long-term studies have revealed minimal increases or decreases in prolactin levels in patients with aripiprazole [Citation45,Citation47,Citation48]. Three studies reported aripiprazole-related new-onset hyperprolactinemia [Citation45,Citation49,Citation50]. Aripiprazole even revealed a lower likelihood of prolactin elevation, when compared to other prolactin-sparing antipsychotics [Citation47,Citation51]. The prevalence rate of aripiprazole-induced hyperprolactinemia was 3.1–9.0% [Citation45,Citation46,Citation50,Citation52–55].

The findings of the two RCTs supports that quetiapine is a relatively prolactin-sparing antipsychotic [Citation30,Citation56]. A great number of studies have shown that quetiapine induces virtually no elevation of prolactin in the blood [Citation30,Citation57–63]. In addition, the prolactin level during treatment with quetiapine, and after switching, decreased [Citation64–67], even returned to normal values [Citation68–72]. Meanwhile, few data suggests that quetiapine can bring about a transient increase in prolactin levels [Citation57,Citation58,Citation73]. Quetiapine correlated low prevalence rates of hyperprolactinemia has been reported to range within 0–29% [Citation74–77].

Ziprasidone was associated with transient elevations in prolactin, which could return to normal levels within the dosage interval [Citation78]. Similar effects on prolactin have been observed in studies of ziprasidone in healthy volunteers [Citation79]. Most reports have indicated that ziprasidone use is associated with a low incidence of prolactin elevation and low to moderate levels of hyperprolactinemia [Citation57,Citation58,Citation61,Citation80,Citation81]. Some studies revealed that treatment with ziprasidone leads to decreased prolactin levels for six weeks [Citation82], 4–8 weeks [Citation83], 18 weeks [Citation84], 44 weeks [Citation85] and one year [Citation86], respectively. However, few trials also reported that ziprasidone induced hyperprolactinemia [Citation87–92].

The most important clinical implication of these findings was that quetiapine should be the best choice when starting a prolactin-sparing antipsychotic for schizophrenia patients due to the best balance between efficacy and acceptability. The results of the present analysis apply only for the acute treatment (4–12 weeks) of schizophrenia. Medical practitioners need to determine whether (and to what extent) these prolactin-sparing antipsychotics work within a clinically reasonable duration. In clinic, the evaluation of efficacy and acceptability after 12 weeks might lead to marked differences in treatment outcome. Globally, the age-standardized prevalence of schizophrenia in 2016 was estimated to be 0.28%, and prevalent cases increased from 13.1 million in 1990–20.9 million cases in 2016, which contributes 13.4 million years of life lived with disability to the burden of the disease globally [Citation93]. Overall, for patients with schizophrenia, approximately half of women of reproductive age and men have elevated prolactin [Citation75,Citation94]. Optimally, patients with hyperprolactinemia secondary to antipsychotic drug treatment should be switched to a prolactin-sparing antipsychotic [Citation95].

The present network meta-analysis was designed according to the standards of the PRISMA-NMA [Citation24] principle. To our knowledge, the present network meta-analysis is the first to address the comparative effects of different prolactin-sparing antipsychotics with the explicit rankings of each outcome and the overall benefit-risk profile. Thus, these present findings may be useful to clinicians in deciding which drug to use. Industry sponsorship might influence the results of the biomedical research, because most studies that validate the newest antipsychotics are supported by pharmaceutical companies that market these drugs [Citation96]. However, network meta-analysis incorporating indirect and direct comparisons could decrease the risk for possible sponsorship bias.

Care should be given in interpreting these conclusions due to the limitations of the present study. First, the present study included a limited number of trials, and some of the estimated results of the analysis relied on indirect comparisons. Second, the potential confounders of the primary studies, especially dose issues, might have influenced the validity of these findings. Third, most of the included studies were placebo-controlled trials, which are mainly designed to meet both ethical and safety requirements for regulatory approval. However, patients from these trials were more likely to be mild [Citation97]. Therefore, a well-designed randomized controlled trial that compares different prolactin-sparing antipsychotics in schizophrenia patients with or without antipsychotic-induced hyperprolactinemia is required to formally determine the comparative benefit-risk profile of each drug.

Conclusion

Considering the low rate of hyperprolactinemia and the highest overall rank possibility, quetiapine may offer an optimal benefit-risk balance when a prolactin-sparing antipsychotic is indicated.

Supplemental material

Supplemental Material

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Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by grants from the National Natural Science Foundation of China (81871052 to C.Z., 81801679 and 81571319 to Y.X.), the Key Projects of the Natural Science Foundation of Tianjin (17JCZDJC35700 to C.Z.), the Tianjin Municipal Health Bureau (2014KR02 to C.Z.), the National Key Research and Development Program of China (2016YFC1307004 to Y.X.), the Shanxi Science and Technology Innovation Training Team’s Multidisciplinary Team for Cognitive Impairment (201705D131027 to Y.X.), Zhejiang Public Welfare Fund Project (LGF18H090002 to D.J), Tianjin Anding Hospital Outstanding Award rewarding 300000 yuan to C.Z., and the key project of Wenzhou Science and Technology Bureau (ZS2017011 to X.L).

References

  • Owen MJ, Sawa A, Mortensen PB. Schizophrenia. Lancet. 2016;388:86–97. doi:10.1016/S0140-6736(15)01121-6.
  • Lieberman JA, First MB. Psychotic disorders. N Engl J Med. 2018;379:270–280. doi:10.1056/NEJMra1801490.
  • de Bartolomeis A, Buonaguro EF, Iasevoli F. Serotonin-glutamate and serotonin-dopamine reciprocal interactions as putative molecular targets for novel antipsychotic treatments: from receptor heterodimers to postsynaptic scaffolding and effector proteins. Psychopharmacology (Berl). 2013;225:1–19. doi:10.1007/s00213-012-2921-8.
  • Madhusoodanan S, Parida S, Jimenez C. Hyperprolactinemia associated with psychotropics–a review. Hum Psychopharmacol. 2010;25:281–297. doi:10.1002/hup.1116.
  • Ben-Jonathan N, Hnasko R. Dopamine as a prolactin (PRL) inhibitor. Endocr Rev. 2001;22:724–763. doi:10.1210/edrv.22.6.0451.
  • Haddad PM, Sharma SG. Adverse effects of atypical antipsychotics: differential risk and clinical implications. CNS Drugs. 2007;21:911–936. doi:10.2165/00023210-200721110-00004.
  • Inder WJ, Castle D. Antipsychotic-induced hyperprolactinaemia. Aust N Z J Psychiatry. 2011;45:830–837. doi:10.3109/00048674.2011.589044.
  • Meaney AM, O’Keane V. Prolactin and schizophrenia: clinical consequences of hyperprolactinaemia. Life Sci. 2002;71:979–992.
  • Dickson RA, Glazer WM. Neuroleptic-induced hyperprolactinemia. Schizophr Res. 1999;35(Suppl):S75–S86.
  • Compton MT, Miller AH. Antipsychotic-induced hyperprolactinemia and sexual dysfunction. Psychopharmacol Bull. 2002;36:143–164.
  • Halbreich U, Kinon BJ, Gilmore JA, et al. Elevated prolactin levels in patients with schizophrenia: mechanisms and related adverse effects. Psychoneuroendocrinology. 2003;28(Suppl 1):53–67.
  • Halbreich U, Rojansky N, Palter S, et al. Decreased bone mineral density in medicated psychiatric patients. Psychosom Med. 1995;57:485–491.
  • Walker SE, Allen SH, Hoffman RW, et al. Review: prolactin: a stimulator of disease activity in systemic lupus erythematosus. Lupus. 1995;4:3–9. doi:10.1177/096120339500400102.
  • Welsch CW, Nagasawa H. Prolactin and murine mammary tumorigenesis: a review. Cancer Res. 1977;37:951–963.
  • Wong-Anuchit C. Clinical management of antipsychotic-induced hyperprolactinemia. Perspect Psychiatr Care. 2016;52:145–152. doi:10.1111/ppc.12111.
  • Boyd A. Bromocriptine and psychosis: a literature review. Psychiatr Q. 1995;66:87–95.
  • Melmed S, Casanueva FF, Hoffman AR, et al. Diagnosis and treatment of hyperprolactinemia: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2011;96:273–288. doi:10.1210/jc.2010-1692.
  • Bushe CJ, Bradley A, Pendlebury J. A review of hyperprolactinaemia and severe mental illness: are there implications for clinical biochemistry? Ann Clin Biochem. 2010;47:292–300. doi:10.1258/acb.2010.010025.
  • Cookson J, Hodgson R, Wildgust HJ. Prolactin, hyperprolactinaemia and antipsychotic treatment: a review and lessons for treatment of early psychosis. J Psychopharmacol. 2012;26:42–51. doi:10.1177/0269881112442016.
  • Kinon BJ, Ahl J, Liu-Seifert H, et al. Improvement in hyperprolactinemia and reproductive comorbidities in patients with schizophrenia switched from conventional antipsychotics or risperidone to olanzapine. Psychoneuroendocrinology. 2006;31:577–588. doi:10.1016/j.psyneuen.2005.12.006.
  • Dogan Bulut S, Bulut S, Tuzer V, et al. The effects of prolactin-raising and prolactin-sparing antipsychotics on prolactin levels and bone mineral density in schizophrenic patients. Noro Psikiyatr Ars. 2014;51:205–210. doi:10.4274/npa.y6628.
  • Montejo AL. Prolactin awareness: an essential consideration for physical health in schizophrenia. Eur Neuropsychopharmacol. 2008;18(Suppl 2):S108–S114. doi:10.1016/j.euroneuro.2008.02.004.
  • Miyamoto BE, Galecki M, Francois D. Guidelines for antipsychotic-induced hyperprolactinemia. Psychiatr Ann. 2015;45:266–272. doi:10.3928/00485713-20150501-09.
  • Hutton B, Salanti G, Caldwell DM, et al. The PRISMA extension statement for reporting of systematic reviews incorporating network meta-analyses of health care interventions: checklist and explanations. Ann Intern Med. 2015;162:777–784. doi:10.7326/M14-2385.
  • Leucht S, Cipriani A, Spineli L, et al. Comparative efficacy and tolerability of 15 antipsychotic drugs in schizophrenia: a multiple-treatments meta-analysis. Lancet. 2013;382:951–962. doi:10.1016/S0140-6736(13)60733-3.
  • Higgins JE. Cochrane handbook for systematic reviews of interventions. Naunyn-Schmiedebergs Archiv für Experimentelle Pathologie und Pharmakologie. 2011;5:S38.
  • van Valkenhoef G, Tervonen T, Zhao J, et al. Multicriteria benefit-risk assessment using network meta-analysis. J Clin Epidemiol. 2012;65:394–403. doi:10.1016/j.jclinepi.2011.09.005.
  • Valkenhoef GV, Tervonen T, Zwinkels T, et al. ADDIS: a decision support system for evidence-based medicine. Decis Support Syst. 2013;55:459–475.
  • Hillege H, Brock BD, Valkenhoef GV, et al. ADDIS: an automated way to do network meta-analysis. Research Report 2012.
  • Arvanitis LA, Miller BG. Multiple fixed doses of “Seroquel” (quetiapine) in patients with acute exacerbation of schizophrenia: a comparison with haloperidol and placebo. The Seroquel trial 13 study group. Biol Psychiatry. 1997;42:233–246.
  • Cantillon M, Prakash A, Alexander A, et al. Dopamine serotonin stabilizer RP5063: a randomized, double-blind, placebo-controlled multicenter trial of safety and efficacy in exacerbation of schizophrenia or schizoaffective disorder. Schizophr Res. 2017;189:126–133. doi:10.1016/j.schres.2017.01.043.
  • Crespo-Facorro B, Perez-Iglesias R, Mata I, et al. Aripiprazole, ziprasidone, and quetiapine in the treatment of first-episode nonaffective psychosis: results of a 6-week, randomized, flexible-dose, open-label comparison. J Clin Psychopharmacol. 2013;33:215–220. doi:10.1097/JCP.0b013e3182825c1e.
  • Cutler AJ, Kalali AH, Weiden PJ, et al. Four-week, double-blind, placebo- and ziprasidone-controlled trial of iloperidone in patients with acute exacerbations of schizophrenia. J Clin Psychopharmacol. 2008;28:S20–S28. doi:10.1097/JCP.0b013e318169d4ce.
  • Durgam S, Cutler AJ, Lu K, et al. Cariprazine in acute exacerbation of schizophrenia: a fixed-dose, phase 3, randomized, double-blind, placebo- and active-controlled trial. J Clin Psychiatry. 2015;76:e1574–e1582. doi:10.4088/JCP.15m09997.
  • Findling RL, Cavus I, Pappadopulos E, et al. Ziprasidone in adolescents with schizophrenia: results from a placebo-controlled efficacy and long-term open-extension study. J Child Adolesc Psychopharmacol. 2013;23:531–544. doi:10.1089/cap.2012.0068.
  • Findling RL, McKenna K, Earley WR, et al. Efficacy and safety of quetiapine in adolescents with schizophrenia investigated in a 6-week, double-blind, placebo-controlled trial. J Child Adolesc Psychopharmacol. 2012;22:327–342. doi:10.1089/cap.2011.0092.
  • Hatta K, Sato K, Hamakawa H, et al. Effectiveness of second-generation antipsychotics with acute-phase schizophrenia. Schizophr Res. 2009;113:49–55. doi:10.1016/j.schres.2009.05.030.
  • Keck P Jr., Buffenstein A, Ferguson J, et al. Ziprasidone 40 and 120 mg/day in the acute exacerbation of schizophrenia and schizoaffective disorder: a 4-week placebo-controlled trial. Psychopharmacology (Berl). 1998;140:173–184.
  • Meltzer HY, Risinger R, Nasrallah HA, et al. A randomized, double-blind, placebo-controlled trial of aripiprazole lauroxil in acute exacerbation of schizophrenia. J Clin Psychiatry. 2015;76:1085–1090. doi:10.4088/JCP.14m09741.
  • Small JG, Hirsch SR, Arvanitis LA, et al. Quetiapine in patients with schizophrenia. A high- and low-dose double-blind comparison with placebo. Seroquel study group. Arch Gen Psychiatry. 1997;54:549–557.
  • Zimbroff D, Warrington L, Loebel A, et al. Comparison of ziprasidone and aripiprazole in acutely ill patients with schizophrenia or schizoaffective disorder: a randomized, double-blind, 4-week study. Int Clin Psychopharmacol. 2007;22:363–370. doi:10.1097/YIC.0b013e32816f7779.
  • Gardner DM, Murphy AL, O’Donnell H, et al. International consensus study of antipsychotic dosing. Am J Psychiatry. 2010;167:686–693. doi:10.1176/appi.ajp.2009.09060802.
  • Ajmal A, Joffe H, Nachtigall LB. Psychotropic-induced hyperprolactinemia: a clinical review. Psychosomatics. 2014;55:29–36. doi:10.1016/j.psym.2013.08.008.
  • Bushe C, Shaw M, Peveler RC. A review of the association between antipsychotic use and hyperprolactinaemia. J Psychopharmacol. 2008;22:46–55. doi:10.1177/0269881107088435.
  • Potkin SG, Saha AR, Kujawa MJ, et al. Aripiprazole, an antipsychotic with a novel mechanism of action, and risperidone vs placebo in patients with schizophrenia and schizoaffective disorder. Arch Gen Psychiatry. 2003;60:681–690. doi:10.1001/archpsyc.60.7.681.
  • Kane JM, Meltzer HY, Carson WH Jr., et al. Aripiprazole for treatment-resistant schizophrenia: results of a multicenter, randomized, double-blind, comparison study versus perphenazine. J Clin Psychiatry. 2007;68:213–223.
  • Chrzanowski WK, Marcus RN, Torbeyns A, et al. Effectiveness of long-term aripiprazole therapy in patients with acutely relapsing or chronic, stable schizophrenia: a 52-week, open-label comparison with olanzapine. Psychopharmacology (Berl). 2006;189:259–266. doi:10.1007/s00213-006-0564-3.
  • Marder SR, McQuade RD, Stock E, et al. Aripiprazole in the treatment of schizophrenia: safety and tolerability in short-term, placebo-controlled trials. Schizophr Res. 2003;61:123–136.
  • Hanssens L, L’Italien G, Loze JY, et al. The effect of antipsychotic medication on sexual function and serum prolactin levels in community-treated schizophrenic patients: results from the schizophrenia trial of aripiprazole (STAR) study (NCT00237913). BMC Psychiatry. 2008;8:95. doi:10.1186/1471-244X-8-95.
  • McQuade RD, Stock E, Marcus R, et al. A comparison of weight change during treatment with olanzapine or aripiprazole: results from a randomized, double-blind study. J Clin Psychiatry. 2004;65(Suppl 18):47–56.
  • Kerwin R, Millet B, Herman E, et al. A multicentre, randomized, naturalistic, open-label study between aripiprazole and standard of care in the management of community-treated schizophrenic patients schizophrenia trial of aripiprazole: (STAR) study. Eur Psychiatry. 2007;22:433–443. doi:10.1016/j.eurpsy.2007.03.002.
  • Lee BH, Kang SG, Kim TW, et al. Hyperprolactinemia induced by low-dosage amisulpride in Korean psychiatric patients. Psychiatry Clin Neurosci. 2012;66:69–73. doi:10.1111/j.1440-1819.2011.02296.x.
  • Pigott TA, Carson WH, Saha AR, et al. Aripiprazole for the prevention of relapse in stabilized patients with chronic schizophrenia: a placebo-controlled 26-week study. J Clin Psychiatry. 2003;64:1048–1056.
  • Kane JM, Carson WH, Saha AR, et al. Efficacy and safety of aripiprazole and haloperidol versus placebo in patients with schizophrenia and schizoaffective disorder. J Clin Psychiatry. 2002;63:763–771.
  • Kasper S, Lerman MN, McQuade RD, et al. Efficacy and safety of aripiprazole vs. haloperidol for long-term maintenance treatment following acute relapse of schizophrenia. Int J Neuropsychopharmacol. 2003;6:325–337. doi:10.1017/S1461145703003651.
  • Potkin SG, Gharabawi GM, Greenspan AJ, et al. A double-blind comparison of risperidone, quetiapine and placebo in patients with schizophrenia experiencing an acute exacerbation requiring hospitalization. Schizophr Res. 2006;85:254–265. doi:10.1016/j.schres.2006.03.027.
  • Hamner M. The effects of atypical antipsychotics on serum prolactin levels. Ann Clin Psychiatry. 2002;14:163–173.
  • Petty RG. Prolactin and antipsychotic medications: mechanism of action. Schizophr Res. 1999;35(Suppl):S67–S73.
  • Haddad PM, Wieck A. Antipsychotic-induced hyperprolactinaemia: mechanisms, clinical features and management. Drugs. 2004;64:2291–2314. doi:10.2165/00003495-200464200-00003.
  • Kim EY, Kim SH, Lee NY, et al. Relationship between prolactin levels and subjective endocrine-related adverse effects in patients with schizophrenia receiving long-term treatment with amisulpride. Pharmacopsychiatry. 2012;45:57–63. doi:10.1055/s-0031-1291175.
  • Conley RR, Kelly DL. Second-generation antipsychotics for schizophrenia: a review of clinical pharmacology and medication-associated side effects. Isr J Psychiatry Relat Sci. 2005;42:51–60.
  • Atmaca M, Kuloglu M, Tezcan E. A new atypical antipsychotic: quetiapine-induced sexual dysfunctions. Int J Impot Res. 2005;17:201–203. doi:10.1038/sj.ijir.3901260.
  • Asmal L, Flegar SJ, Wang J, et al. Quetiapine versus other atypical antipsychotics for schizophrenia. Cochrane Database Syst Rev. 2013:CD006625. doi:10.1002/14651858.CD006625.pub3.
  • Peuskens J, Link CG. A comparison of quetiapine and chlorpromazine in the treatment of schizophrenia. Acta Psychiatr Scand. 1997;96:265–273.
  • Riedel M, Muller N, Strassnig M, et al. Quetiapine has equivalent efficacy and superior tolerability to risperidone in the treatment of schizophrenia with predominantly negative symptoms. Eur Arch Psychiatry Clin Neurosci. 2005;255:432–437. doi:10.1007/s00406-005-0622-6.
  • Buckley PF, Goldstein JM, Emsley RA. Efficacy and tolerability of quetiapine in poorly responsive, chronic schizophrenia. Schizophr Res. 2004;66:143–150. doi:10.1016/j.schres.2003.06.001.
  • Byerly MJ, Lescouflair E, Weber MT, et al. An open-label trial of quetiapine for antipsychotic-induced sexual dysfunction. J Sex Marital Ther. 2004;30:325–332. doi:10.1080/00926230490465082.
  • Arakawa R, Okumura M, Ito H, et al. Positron emission tomography measurement of dopamine D(2) receptor occupancy in the pituitary and cerebral cortex: relation to antipsychotic-induced hyperprolactinemia. J Clin Psychiatry. 2010;71:1131–1137. doi:10.4088/JCP.08m04307yel.
  • Kelly DL, Conley RR. A randomized double-blind 12-week study of quetiapine, risperidone or fluphenazine on sexual functioning in people with schizophrenia. Psychoneuroendocrinology. 2006;31:340–346. doi:10.1016/j.psyneuen.2005.08.010.
  • Emsley R, Turner HJ, Schronen J, et al. A single-blind, randomized trial comparing quetiapine and haloperidol in the treatment of tardive dyskinesia. J Clin Psychiatry. 2004;65:696–701.
  • Copolov DL, Link CG, Kowalcyk B. A multicentre, double-blind, randomized comparison of quetiapine (ICI 204,636, ‘seroquel’) and haloperidol in schizophrenia. Psychol Med. 2000;30:95–105.
  • King DJ, Link CG, Kowalcyk B. A comparison of bd and tid dose regimens of quetiapine (Seroquel) in the treatment of schizophrenia. Psychopharmacology (Berl). 1998;137:139–146.
  • Turrone P, Kapur S, Seeman MV, et al. Elevation of prolactin levels by atypical antipsychotics. Am J Psychiatry. 2002;159:133–135. doi:10.1176/appi.ajp.159.1.133.
  • Wong J, Seeman MV. Prolactin, menstrual irregularities, quality of life. Schizophr Res. 2007;91:270–271. doi:10.1016/j.schres.2006.11.004.
  • Montgomery J, Winterbottom E, Jessani M, et al. Prevalence of hyperprolactinemia in schizophrenia: association with typical and atypical antipsychotic treatment. J Clin Psychiatry. 2004;65:1491–1498.
  • Bushe C, Shaw M. Prevalence of hyperprolactinaemia in a naturalistic cohort of schizophrenia and bipolar outpatients during treatment with typical and atypical antipsychotics. J Psychopharmacol. 2007;21:768–773. doi:10.1177/0269881107078281.
  • Bushe C, Yeomans D, Floyd T, et al. Categorical prevalence and severity of hyperprolactinaemia in two UK cohorts of patients with severe mental illness during treatment with antipsychotics. J Psychopharmacol. 2008;22:56–62. doi:10.1177/0269881107088436.
  • Goff DC, Posever T, Herz L, et al. An exploratory haloperidol-controlled dose-finding study of ziprasidone in hospitalized patients with schizophrenia or schizoaffective disorder. J Clin Psychopharmacol. 1998;18:296–304.
  • Miceli JJ, Wilner KD, Hansen RA, et al. Single- and multiple-dose pharmacokinetics of ziprasidone under non-fasting conditions in healthy male volunteers. Br J Clin Pharmacol. 2000;49(Suppl 1):5S–13S.
  • Addington DE, Pantelis C, Dineen M, et al. Efficacy and tolerability of ziprasidone versus risperidone in patients with acute exacerbation of schizophrenia or schizoaffective disorder: an 8-week, double-blind, multicenter trial. J Clin Psychiatry. 2004;65:1624–1633.
  • Kelly DL, Conley RR. Sexuality and schizophrenia: a review. Schizophr Bull. 2004;30:767–779.
  • Zhang H, Li H, Shu L, et al. Double-blind comparison of ziprasidone and risperidone in the treatment of Chinese patients with acute exacerbation of schizophrenia. Neuropsychiatr Dis Treat. 2011;7:77–85. doi:10.2147/NDT.S16664.
  • Tschoner A, Engl J, Rettenbacher MA, et al. Is second-generation antipsychotic-induced hyperprolactinemia due to biologically active prolactin or to biologically inactive macroprolactin? results from a prospective study. J Clin Psychiatry. 2009;70:293–294.
  • Sacchetti E, Galluzzo A, Valsecchi P, et al. Ziprasidone vs clozapine in schizophrenia patients refractory to multiple antipsychotic treatments: the MOZART study. Schizophr Res. 2009;110:80–89. doi:10.1016/j.schres.2009.02.017.
  • Addington DE, Labelle A, Kulkarni J, et al. A comparison of ziprasidone and risperidone in the long-term treatment of schizophrenia: a 44-week, double-blind, continuation study. Can J Psychiatry. 2009;54:46–54. doi:10.1177/070674370905400108.
  • Arato M, O’Connor R, Meltzer HY, et al. A 1-year, double-blind, placebo-controlled trial of ziprasidone 40, 80 and 160 mg/day in chronic schizophrenia: the ziprasidone Extended Use in schizophrenia (ZEUS) study. Int Clin Psychopharmacol. 2002;17:207–215.
  • Tsuboi T, Bies RR, Suzuki T, et al. Hyperprolactinemia and estimated dopamine D2 receptor occupancy in patients with schizophrenia: analysis of the CATIE data. Prog Neuropsychopharmacol Biol Psychiatry. 2013;45:178–182. doi:10.1016/j.pnpbp.2013.05.010.
  • Kim SW, Shin IS, Kim JM, et al. Effectiveness of switching from aripiprazole to ziprasidone in patients with schizophrenia. Clin Neuropharmacol. 2010;33:121–125. doi:10.1097/WNF.0b013e3181d52b85.
  • Wu XL, Wang JH, Hu SH, et al. Serum prolactin levels and the acute-phase efficacy in drug-naive schizophrenia treated with ziprasidone and olanzapine (translated version). East Asian Arch Psychiatry. 2012;22:7–11.
  • Suzuki T, Graff-Guerrero A, Uchida H, et al. Dopamine D(2)/(3) occupancy of ziprasidone across a day: a within-subject PET study. Psychopharmacology (Berl). 2013;228:43–51. doi:10.1007/s00213-013-3012-1.
  • Grootens KP, van Veelen NM, Peuskens J, et al. Ziprasidone vs olanzapine in recent-onset schizophrenia and schizoaffective disorder: results of an 8-week double-blind randomized controlled trial. Schizophr Bull. 2011;37:352–361. doi:10.1093/schbul/sbp037.
  • Zink M, Kuwilsky A, Krumm B, et al. Efficacy and tolerability of ziprasidone versus risperidone as augmentation in patients partially responsive to clozapine: a randomised controlled clinical trial. J Psychopharmacol. 2009;23:305–314. doi:10.1177/0269881108089593.
  • Charlson FJ, Ferrari AJ, Santomauro DF, et al. Global epidemiology and burden of schizophrenia: findings from the global burden of disease study 2016. Schizophr Bull. 2018;44:1195–1203. doi:10.1093/schbul/sby058.
  • Kinon BJ, Gilmore JA, Liu H, et al. Prevalence of hyperprolactinemia in schizophrenic patients treated with conventional antipsychotic medications or risperidone. Psychoneuroendocrinology. 2003;28(Suppl 2):55–68.
  • Halbreich U, Kahn LS. Hyperprolactinemia and schizophrenia: mechanisms and clinical aspects. J Psychiatr Pract. 2003;9:344–353.
  • Bekelman JE, Li Y, Gross CP. Scope and impact of financial conflicts of interest in biomedical research: a systematic review. JAMA. 2003;289:454–465.
  • Kirsch I, Moncrieff J. Clinical trials and the response rate illusion. Contemp Clin Trials. 2007;28:348–351. doi:10.1016/j.cct.2006.10.012.