Efficacy and tolerability of topiramate-augmentation therapy for schizophrenia: a systematic review and meta-analysis of randomized controlled trials

A review on side effect management of second-generation antipsychotics to treat schizophrenia: a drug safety perspective

INTRODUCTION

Effective side effects management present a challenge in antipsychotic treatment with second-generation antipsychotics (SGAs). In recent years, most of the commonly used SGAs, except for clozapine, have been shown to differ only slightly in their effectiveness, but considerably regarding perceived side effects, safety profiles, and compatibility to preexisting medical conditions.

AREAS COVERED

The current state of available evidence on side-effect management in SGA treatment of patients with schizophrenia spectrum disorders (SSD) is reviewed. In addition, current guideline recommendations are summarized, highlighting evidence gaps.

EXPERT OPINION

SGA safety and side effects needs to be considered in treatment planning. Shared decision-making assistants (SDMA) can support patients, practitioners and relatives to orient their decisions toward avoiding side effects relevant to patients' adherence. Alongside general measures like psychosocial and psychotherapeutic care, switching to better tolerated SGAs can be considered a relatively safe strategy. By contrast, novel meta-analytical evidence emphasizes that dose reduction of SGAs can statistically increase the risk of relapse and other unfavorable outcomes. Further, depending on the type and severity of SGA-related side effects, specific treatments can be used to alleviate induced side effects (e.g. add-on metformin to reduce weight-gain). Finally, discontinuation should be reserved for acute emergencies.

Comparison of olanzapine-induced weight gain and metabolism abnormalities between topiramate and vitamin C in patients with schizophrenia: a preliminary study

Background

Topiramate (TPM) may reduce olanzapine (OLZ)-related weight gain and metabolism abnormalities in patients with schizophrenia. However, differences in the efficacy of OLZ-related weight gain and metabolism abnormalities between TPM and vitamin C (VC) are not clear. This study aimed to investigate whether TPM is more effective than VC in reducing OLZ-induced weight gain and metabolic abnormalities in patients with schizophrenia and explore their patterns.

Methods

This was a 12-week longitudinal comparison study in OLZ-treated patients with schizophrenia. Twenty-two patients who received OLZ monotherapy plus VC treatment (OLZ + VC group) was matched to 22 patients who received OLZ monotherapy plus TPM treatment (OLZ + TPM group). Body mass index (BMI) and metabolism indicators were measured at baseline and 12-weeks follow-up.

Results

A significant difference in triglyceride (TG) levels at different time points (pre-treatment: F = 7.89, p = 0.008; 4-weeks treatment: F = 13.19, p = 0.001; 12-weeks treatment: F = 54.48, p < 0.001) was found. Latent profile analysis demonstrated that a 2-class model for OLZ + TPM group (high vs. low BMI in the first 4 weeks) and OLZ + VC group (high vs. low), respectively.

Conclusion

Our findings suggested that TPM could better mitigates OLZ-induced increase in TG levels. The trajectories of change also differed in all metabolic indexes over time between the two groups.

Pharmacological interventions for prevention of weight gain in people with schizophrenia

BACKGROUND

Antipsychotic-induced weight gain is an extremely common problem in people with schizophrenia and is associated with increased morbidity and mortality. Adjunctive pharmacological interventions may be necessary to help manage antipsychotic-induced weight gain. This review splits and updates a previous Cochrane Review that focused on both pharmacological and behavioural approaches to this problem.

OBJECTIVES

To determine the effectiveness of pharmacological interventions for preventing antipsychotic-induced weight gain in people with schizophrenia.

SEARCH METHODS

The Cochrane Schizophrenia Information Specialist searched Cochrane Schizophrenia's Register of Trials on 10 February 2021. There are no language, date, document type, or publication status limitations for inclusion of records in the register.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that examined any adjunctive pharmacological intervention for preventing weight gain in people with schizophrenia or schizophrenia-like illnesses who use antipsychotic medications.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed the quality of included studies. For continuous outcomes, we combined mean differences (MD) in endpoint and change data in the analysis. For dichotomous outcomes, we calculated risk ratios (RR). We assessed risk of bias for included studies and used GRADE to judge certainty of evidence and create summary of findings tables. The primary outcomes for this review were clinically important change in weight, clinically important change in body mass index (BMI), leaving the study early, compliance with treatment, and frequency of nausea. The included studies rarely reported these outcomes, so, post hoc, we added two new outcomes, average endpoint/change in weight and average endpoint/change in BMI.

MAIN RESULTS

Seventeen RCTs, with a total of 1388 participants, met the inclusion criteria for the review. Five studies investigated metformin, three topiramate, three H2 antagonists, three monoamine modulators, and one each investigated monoamine modulators plus betahistine, melatonin and samidorphan. The comparator in all studies was placebo or no treatment (i.e. standard care alone). We synthesised all studies in a quantitative meta-analysis. Most studies inadequately reported their methods of allocation concealment and blinding of participants and personnel. The resulting risk of bias and often small sample sizes limited the overall certainty of the evidence. Only one reboxetine study reported the primary outcome, number of participants with clinically important change in weight. Fewer people in the treatment condition experienced weight gains of more than 5% and more than 7% of their bodyweight than those in the placebo group (> 5% weight gain RR 0.27, 95% confidence interval (CI) 0.11 to 0.65; 1 study, 43 participants; > 7% weight gain RR 0.24, 95% CI 0.07 to 0.83; 1 study, 43 participants; very low-certainty evidence). No studies reported the primary outcomes, 'clinically important change in BMI', or 'compliance with treatment'. However, several studies reported 'average endpoint/change in body weight' or 'average endpoint/change in BMI'. Metformin may be effective in preventing weight gain (MD -4.03 kg, 95% CI -5.78 to -2.28; 4 studies, 131 participants; low-certainty evidence); and BMI increase (MD -1.63 kg/m2, 95% CI -2.96 to -0.29; 5 studies, 227 participants; low-certainty evidence). Other agents that may be slightly effective in preventing weight gain include H2 antagonists such as nizatidine, famotidine and ranitidine (MD -1.32 kg, 95% CI -2.09 to -0.56; 3 studies, 248 participants; low-certainty evidence) and monoamine modulators such as reboxetine and fluoxetine (weight: MD -1.89 kg, 95% CI -3.31 to -0.47; 3 studies, 103 participants; low-certainty evidence; BMI: MD -0.66 kg/m2, 95% CI -1.05 to -0.26; 3 studies, 103 participants; low-certainty evidence). Topiramate did not appear effective in preventing weight gain (MD -4.82 kg, 95% CI -9.99 to 0.35; 3 studies, 168 participants; very low-certainty evidence). For all agents, there was no difference between groups in terms of individuals leaving the study or reports of nausea. However, the results of these outcomes are uncertain given the very low-certainty evidence.

AUTHORS' CONCLUSIONS

There is low-certainty evidence to suggest that metformin may be effective in preventing weight gain. Interpretation of this result and those for other agents, is limited by the small number of studies, small sample size, and short study duration. In future, we need studies that are adequately powered and with longer treatment durations to further evaluate the efficacy and safety of interventions for managing weight gain.

Randomised, placebo-controlled trial on topiramate add-on therapy for weight reduction and symptomatology in overweight/obese persons with schizophrenia

INTRODUCTION

Higher cardiovascular mortality is seen with schizophrenia due to the disorder itself and antipsychotic use. South Asians are more vulnerable to developing metabolic disorders than others. Resource-limited settings in South Asia have only a few mental health professionals, and individualised case management is mostly unavailable. Therefore, there is less monitoring and personalised support for diet and physical exercise programmes. Topiramate is useful for weight reduction and improvement of psychopathology in schizophrenia. However, there has been only one previous randomised controlled trial (RCT) done in South Asia, which possesses a quarter of the world's population.

METHODS

We conducted a double-blind RCT in an outpatient setting in Sri Lanka. We compared topiramate 100 mg/day with a placebo in overweight/obese adults with schizophrenia who have been on antipsychotics for at least a year. We obtained monthly anthropometric measurements and assessed the symptomatology using the brief psychiatric rating scale (BPRS).

RESULTS

Fifty patients each in the topiramate and placebo arms completed the study. Topiramate add-on therapy led to significant weight/Body Mass Index reduction and improved symptomatology as measured by the BPRS compared to the placebo. The topiramate group had significantly more reporting of loss of appetite.

DISCUSSION

According to available data, this is the RCT with most participants assessing the use of topiramate in schizophrenia and only the second in South Asia. Topiramate was shown to be useful for weight reduction and symptomatic improvement in persons with schizophrenia in a resource-limited setting in South Asia.

Revisiting the Efficacy and Tolerability of Topiramate for Tic Disorders: A Meta-Analysis

Background: Tic disorders (TDs) are chronic neuropsychiatric disorders that usually begin in childhood. Currently, antipsychotic drugs, such as aripiprazole and risperidone, are frequently used to treat TD. However, adverse reactions limit their further usage. The efficacy of topiramate has been reported in recent studies. This study aimed to investigate the efficacy and tolerability of topiramate in the treatment of children with TDs. Methods: In this study, we performed a meta-analysis to assess the efficacy and tolerability of topiramate for TDs and identified the randomized controlled trials to evaluate topiramate for children with TDs from PubMed, the China National Knowledge Infrastructure database, Web of Science, and relevant reference lists. Quality assessment followed the Cochrane Handbook for Systematic Reviews of Interventions. A modified Jadad scale was used to assess the quality of included studies. Risk ratio (RR) was calculated as the effect size of efficacy and tolerability of topiramate for TDs. Results: A total of 15 studies involving 1070 participants aged 2-17 were included in the present meta-analysis, and 693 (64.71%) participants were male cases, with 14 studies evaluating the efficacy of topiramate for the treatment of TD. The results suggested that topiramate was more effective than control drugs (RR: 1.13, 95% confidence interval: [1.06-1.20], I² = 36%, Q = 20.31, p = 0.09). For the adverse events, there were 15 trials included in the meta-analysis, and the results showed that topiramate had fewer adverse events than control drugs (RR: 0.54, 95% confidence interval: [0.46-0.65], I² = 45%, Q = 25.49, p = 0.03). Conclusion: Compared with haloperidol and tiapride, topiramate appears to be a promising medication with good efficacy and tolerability for children with TDs. In future studies, large-sample, double-blind, placebo-controlled trials are needed to confirm its efficacy and tolerability compared with atypical antipsychotic agents (such as risperidone or aripiprazole).

Alcohol Use Disorder and Schizophrenia or Schizoaffective Disorder

Schizophrenia and schizoaffective disorder are schizophrenia spectrum disorders that cause significant disability. Among individuals who have schizophrenia or schizoaffective disorder, alcohol use disorder (AUD) is common, and it contributes to worse outcomes than for those who do not have co-occurring substance use disorder. Common neurobiological mechanisms, including dysfunction in brain reward circuitry, may explain the high rates of co-occurrence of schizophrenia and AUD or other substance use disorders. Optimal treatment combines pharmacologic intervention and other therapeutic modalities to address both the psychotic disorder and AUD. Further research on the etiology of these co-occurring disorders and on treatment of affected individuals is needed.

Topiramate mitigates weight gain in antipsychotic-treated patients with schizophrenia: meta-analysis of randomised controlled trials

OBJECTIVE

Weight gain is one of the most challenging issues in patients with schizophrenia treated with antipsychotics. Several meta-analyses have been conducted to review the efficacy of topiramate in reducing weight, however, several issues regarding the methodology had arisen of which make the results remain ambiguous.

METHODS

We conducted a meta-analysis of randomised controlled trials about the use of topiramate in patients with schizophrenia for weight reduction. Ten double-blinded randomised placebo-controlled trials and seven open-label randomised controlled trials included 905 patients.

RESULTS

Patients treated with topiramate experienced a greater reduction in body weight and BMI. Patients in countries of the lower overweight population showed more significant BMI reduction. Besides, studies from the Middle East and South Asia showed the greatest effect in body weight change, followed by East Asia, then Europe/America. Topiramate group was outperformed control group with significant psychopathology improvement. No difference between two groups regarding the overall side effects.

CONCLUSIONS

Topiramate was significantly superior to control group in mitigating weight gain and psychopathology in antipsychotic-treated patients with schizophrenia. The effects of topiramate augmentation need further investigations in larger definitive studies using methodological rigor and thorough assessments.

Clinical Trials and Therapeutic Rationale for Drug Repurposing in Schizophrenia

There is a paucity of efficacious novel drugs to address high rates of treatment resistance and refractory symptoms in schizophrenia. The identification of novel therapeutic indications for approved drugs-drug repurposing-has the potential to expedite clinical trials and reduce the costly risk of failure which currently limits central nervous system drug discovery efforts. In the present Review we discuss the historical role of drug repurposing in schizophrenia drug discovery and review the main classes of repurposing candidates currently in clinical trials for schizophrenia in terms of their therapeutic rationale, mechanisms of action, and preliminary results from clinical trials. Subsequently we outline the challenges and limitations which face the clinical repurposing pipeline and how novel technologies might serve to address these.

Efficacy and tolerability of fluvoxamine in adults with social anxiety disorder: A meta-analysis

BACKGROUND

No meta-analysis for estimating the comprehensive efficacy and tolerability of fluvoxamine in patients with social anxiety disorder (SAD) has been published.

OBJECTIVE

To investigate the efficacy and tolerability of fluvoxamine in adults with SAD, trials meeting the following criteria were identified: population: ≥18 years of age with a diagnosis of SAD; intervention: fluvoxamine; study design: placebo-controlled randomized controlled trials (RCTs); outcomes: efficacy and tolerability outcomes.

METHODS

We conducted a comprehensive search of PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and ClinicalTrials.gov for RCTs on January 3, 2018. Review Manager 5.3 and Stata Version 12.0 software were used for all statistical analyses. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated for continuous variables, and odds ratios (ORs) with 95% CIs were calculated for dichotomous variables. Cochrane Collaboration's risk of bias tool was used to assess the likelihood of risk of bias. Efficacy was assessed by mean changes in the Liebowitz Social Anxiety scale (LSAS) total score and the Clinical Global Impression Severity of Illness (CGI-S) score as well as the response rate. Tolerability was mainly assessed by the discontinuation rate due to adverse events (AEs) and the incidence of most frequent treatment-emergent AEs (TEAEs).

RESULTS

This meta-analysis included 5 RCTs. Mean changes in LSAS total and CGI-S scores were both significantly greater in patients treated with fluvoxamine than those treated with placebo (LSAS: MD = 11.90, 95% CI = 8.09-15.71, P < .001; CGI-S: MD = 0.52, 95% CI = 0.33-0.72, P < .001). Response rate was higher in fluvoxamine group as compared with placebo (OR = 1.71, 95% CI = 1.30-2.24, P < .001). Additionally, mean change in the Sheehan disability scale score was significantly greater in fluvoxamine group than placebo group (OR = 2.11, 95% CI = 1.03-3.18, P < .001). The discontinuation rate due to AEs was higher in patients that received fluvoxamine compared to those received placebo (OR = 5.99, 95% CI = 2.24-15.99, P < .001), as was the incidence of overall TEAEs (any AE) (OR = 2.66, 95% CI = 1.77-4.02, P < .001). However, the incidence of serious AEs was not significantly different between the 2 groups (OR = 0.99, 95% CI = 0.25-3.89, P = .99).

CONCLUSION

Fluvoxamine was found to be effective in adult patients with SAD, with acceptable tolerability.

Efficacy and tolerability of short-term duloxetine treatment in adults with generalized anxiety disorder: A meta-analysis

OBJECTIVE

To investigate the efficacy and tolerability of duloxetine during short-term treatment in adults with generalized anxiety disorder (GAD).

METHODS

We conducted a comprehensive literature review of the PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and ClinicalTrials databases for randomized controlled trials(RCTs) comparing duloxetine or duloxetine plus other antipsychotics with placebo for the treatment of GAD in adults. Outcome measures were (1) efficacy, assessed by the Hospital Anxiety and Depression Scale(HADS) anxiety subscale score, the Hamilton Rating Scale for Anxiety(HAM-A) psychic and somatic anxiety factor scores, and response and remission rates based on total scores of HAM-A; (2) tolerability, assessed by discontinuation rate due to adverse events, the incidence of treatment emergent adverse events(TEAEs) and serious adverse events(SAEs). Review Manager 5.3 and Stata Version 12.0 software were used for all statistical analyses.

RESULTS

The meta-analysis included 8 RCTs. Mean changes in the HADS anxiety subscale score [mean difference(MD) = 2.32, 95% confidence interval(CI) 1.77-2.88, P<0.00001] and HAM-A psychic anxiety factor score were significantly greater in patients with GAD that received duloxetine compared to those that received placebo (MD = 2.15, 95%CI 1.61-2.68, P<0.00001). However, there was no difference in mean change in the HAM-A somatic anxiety factor score (MD = 1.13, 95%CI 0.67-1.58, P<0.00001). Discontinuation rate due to AEs in the duloxetine group was significantly higher than the placebo group [odds ratio(OR) = 2.62, 95%CI 1.35-5.06, P = 0.004]. The incidence of any TEAE was significantly increased in patients that received duloxetine (OR = 1.76, 95%CI 1.36-2.28, P<0.0001), but there was no significant difference in the incidence of SAEs (OR = 1.13, 95%CI 0.52-2.47, P = 0.75).

CONCLUSION

Duloxetine resulted in a greater improvement in symptoms of psychic anxiety and similar changes in symptoms of somatic anxiety compared to placebo during short-term treatment in adults with GAD and its tolerability was acceptable.

Short-term efficacy and tolerability of venlafaxine extended release in adults with generalized anxiety disorder without depression: A meta-analysis

Background

Although efficacy of venlafaxine extended release (XR) for generalized anxiety disorder (GAD) has been reported in previous analyses in 2002 and 2004, the sample size was rather small and estimate of safety or tolerability was not clear. The present analysis had the advantage of large sample size and provided evidence for tolerability.

Methods

Literature databases were searched, including Pubmed, Embase, Cochrane Central Register of Controlled Trials, Web of science and clinical trials. 10 eligible articles were finally selected and data was extracted and logged into the Review Manager 5.3 by two independent authors. The risk of bias was evaluated by the Cochrane Collaboration’s Risk of Bias Tool and the stability of the results was assessed by sensitivity analysis. The publication bias was assessed by funnel plot and Egger’s/Begg’s test using Stata Version 12.0 software.

Results

In the current meta-analysis, 10 articles (14 studies) satisfying the inclusion criteria were analyzed. As efficacy outcomes, our findings indicated venlafaxine XR was significantly more effective than placebo according to mean change of the Hamilton Rating Scale for Anxiety total scores [mean difference = 3.31, 95% confidence interval(CI) 1.44–5.18, P = 0.0005], response [odds ratio(OR) = 1.83, 95%CI 1.58–2.12, P<0.00001], and remission (OR = 2.55, 95%CI 1.36–4.78, P = 0.003). In terms of tolerability, the most frequently reported treatment-emergent adverse events were nausea, dry mouth, dizziness, insomnia, somnolence, and headache. In addition, discontinuation due to all-cause (OR = 1.17, 95%CI 0.92–1.49, P = 0.19) was not significantly different between the two groups, whereas discontinuation due to adverse events was statistically higher in the venlafaxine XR group compared with the placebo treatment (OR = 2.80, 95%CI 2.21–3.54, P<0.00001) and discontinuation due to inefficacy was lower in venlafaxine than placebo treatment (OR = 0.26, 95%CI 0.17–0.40, P<0.00001). There was no significant publication bias and sensitivity analysis showed that our analysis exhibited high stability.

Conclusion

We concluded that venlafaxine XR (75–225 mg/day) is an effective and well-tolerated pharmacological treatment option for adult patients with GAD.