Methylphenidate for attention deficit hyperactivity disorder (ADHD) in children and adolescents - assessment of adverse events in non-randomised studies

Ivabradine for coronary artery disease and/or heart failure-a protocol for a systematic review of randomised clinical trials with meta-analysis and Trial Sequential Analysis

BACKGROUND

Coronary artery disease and heart failure are both highly prevalent diseases with a global prevalence of 93 million and 40 million. These patients are at increased risk of morbidity and mortality. The management of these patients involves medical therapy, and both diseases can be treated using the heart rate-lowering drug ivabradine. However, the evidence regarding the use of ivabradine in the treatment of coronary artery disease and/or heart failure is unclear. Our objective is to assess the beneficial and harmful effects of ivabradine in the treatment of coronary artery disease and/or heart failure.

METHODS

This protocol for a systematic review was undertaken using the recommendations of The Cochrane Collaboration, the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P), and the eight-step assessment procedure suggested by Jakobsen and colleagues. We plan to include all relevant randomised clinical trials assessing the use of ivabradine in the treatment of coronary artery disease and/or heart failure. We will search the Cochrane Central Register of Controlled Trials (CENTRAL), Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica database (EMBASE), Latin American and Caribbean Health Sciences Literature (LILACS), Science Citation Index Expanded on Web of Science, Chinese Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Chinese Science Journal Database (VIP), and BIOSIS in order to identify relevant trials. We will begin the searches in February 2019. All included trials will be assessed and classified at low risk of bias or at high risk of bias. Our primary conclusions will be based on the results from the primary outcomes at low risk of bias. Extracted data will be analysed using Review Manager 5.3 and Trial Sequential Analysis 0.9.5.10. We will create a 'Summary of Findings' table in which we will present our primary and secondary outcomes, and we will assess the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

DISCUSSION

The systematic review will have the potential to aid clinicians in decision-making regarding ivabradine and to benefit patients with coronary artery disease and/or heart failure.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018112082.

Methylphenidate modifies activity in the prefrontal and parietal cortex accelerating the time judgment

Methylphenidate produces its effects via actions on cortical areas involved with attention and working memory, which have a direct role in time estimation judgment tasks. In particular, the prefrontal and parietal cortex has been the target of several studies to understand the effect of methylphenidate on executive functions and time interval perception. However, it has not yet been studied whether acute administration of methylphenidate influences performance in time estimation task and the changes in alpha band absolute power in the prefrontal and parietal cortex. The current study investigates the influence of the acute use of methylphenidate in both performance and judgment in the time estimation interpretation through the alpha band absolute power activity in the prefrontal and parietal cortex. This is a double-blind, crossover study with a sample of 32 subjects under control (placebo) and experimental (methylphenidate) conditions with absolute alpha band power analysis during a time estimation task. We observed that methylphenidate does not influence task performance (p > 0.05), but it increases the time interval underestimation by over 7 s (p < 0.001) with a concomitant decrease in absolute alpha band power in the ventrolateral prefrontal cortex and dorsolateral prefrontal cortex and parietal cortex (p < 0.001). Acute use of methylphenidate increases the time interval underestimation, consistent with reduced accuracy of the internal clock mechanisms. Furthermore, acute use of methylphenidate influences the absolute alpha band power over the dorsolateral prefrontal cortex, ventrolateral prefrontal cortex, and parietal cortex.

Acetyl-L-carnitine for patients with hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a common and devastating neuropsychiatric complication of acute liver failure or chronic liver disease. Ammonia content in the blood seems to play a role in the development of hepatic encephalopathy. Treatment for hepatic encephalopathy is complex. Acetyl-L-carnitine is a substance that may reduce ammonia toxicity. This review assessed the benefits and harms of acetyl-L-carnitine for patients with hepatic encephalopathy.

OBJECTIVES

To assess the benefits and harms of acetyl-L-carnitine for patients with hepatic encephalopathy.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, and Science Citation Index Expanded for randomised clinical trials. We sought additional randomised clinical trials from the World Health Organization Clinical Trials Search Portal and ClinicalTrials.gov. We performed all electronic searches until 10 September 2018. We looked through the reference lists of retrieved publications and review articles, and we searched the FDA and EMA websites.

SELECTION CRITERIA

We searched for randomised clinical trials in any setting, recruiting people with hepatic encephalopathy. Trials were eligible for inclusion if they compared acetyl-L-carnitine plus standard care (e.g. antibiotics, lactulose) versus placebo or no acetyl-L-carnitine plus standard care. We are well aware that by selecting randomised clinical trials, we placed greater focus on potential benefits than on potential harms.

DATA COLLECTION AND ANALYSIS

We selected randomised clinical trials, assessed risk of bias in eight domains, and extracted data in a duplicate and independent fashion. We estimated risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes. We measured statistical heterogeneity using I² and D² statistics. We subjected our analyses to fixed-effect and random-effects model meta-analyses. We assessed bias risk domains to control systematic errors. We assessed overall quality of the data for each individual outcome by using the GRADE approach.

MAIN RESULTS

We identified five randomised clinical trials involving 398 participants. All trials included only participants with cirrhosis as the underlying cause of hepatic encephalopathy. Trials included participants with covert or overt hepatic encephalopathy. All trials were conducted in Italy by a single team and assessed acetyl-L-carnitine compared with placebo. Oral intervention was the most frequent route of administration. All trials were at high risk of bias and were underpowered. None of the trials were sponsored by the pharmaceutical industry.None of the identified trials reported information on all-cause mortality, serious adverse events, or days of hospitalisation. Only one trial assessed quality of life using the Short Form (SF)-36 scale (67 participants; very low-quality evidence). The effects of acetyl-L-carnitine compared with placebo on general health at 90 days are uncertain (MD -6.20 points, 95% confidence interval (CI) -9.51 to -2.89). Results for additional domains of the SF-36 are also uncertain. One trial assessed fatigue using the Wessely and Powell test (121 participants; very low-quality evidence). The effects are uncertain in people with moderate-grade hepatic encephalopathy (mental fatigue: MD 0.40 points, 95% CI -0.21 to 1.01; physical fatigue: MD -0.20 points, 95% CI -0.92 to 0.52) and mild-grade hepatic encephalopathy (mental fatigue: -0.80 points, 95% CI -1.48 to -0.12; physical fatigue: 0.20 points, 95% CI -0.72 to 1.12). Meta-analysis showed a reduction in blood ammonium levels favouring acetyl-L-carnitine versus placebo (MD -13.06 mg/dL, 95% CI -17.24 to -8.99; 387 participants; 5 trials; very low-quality evidence). It is unclear whether acetyl-L-carnitine versus placebo increases the risk of non-serious adverse events (8/126 (6.34%) vs 3/120 (2.50%); RR 2.51, 95% CI 0.68 to 9.22; 2 trials; very low-quality evidence). Overall, adverse events data were poorly reported and harms may have been underestimated.

AUTHORS' CONCLUSIONS

This Cochrane systematic review analysed a heterogeneous group of five trials at high risk of bias and with high risk of random errors conducted by only one research team. We assessed acetyl-L-carnitine versus placebo in participants with cirrhosis with covert or overt hepatic encephalopathy. Hence, we have no data on the drug for hepatic encephalopathy in acute liver failure. We found no information about all-cause mortality, serious adverse events, or days of hospitalisation. We found no clear differences in effect between acetyl-L-carnitine and placebo regarding quality of life, fatigue, and non-serious adverse events. Acetyl-L-carnitine reduces blood ammonium levels compared with placebo. We rated all evidence as of very low quality due to pitfalls in design and execution, inconsistency, small sample sizes, and very few events. The harms profile for acetyl-L-carnitine is presently unclear. Accordingly, we need further randomised clinical trials to assess acetyl-L-carnitine versus placebo conducted according to the SPIRIT statements and reported according to the CONSORT statements.

Protective potential of Vitamin E against methylphenidate-induced male gonadal changes in albino rats

OBJECTIVE

Attention deficit hyperactivity disorder ranks among the top neuropsychiatric disorder of childhood and adolescents. Methylphenidate (MPH) is the most frequently used pharmacologic agent to treat this condition. Its long-term use has been associated with many unwanted and adverse effects on many organs including male gonads, but so far no study has been done to find out a protective agent. This study investigated the protective potential of Vitamin E (Vit E) against the microscopic and morphometric alterations in male gonads induced by MPH, using albino rats.

METHODS

Adult male albino rats were assigned into three equal groups including one control and two experimental groups. Experimental groups administered with MPH (10 mg/kg) and MPH (10 mg/kg) + Vit E orally (50 mg/kg), daily for 40 days. Testes of the sacrificed animals were removed, processed, and stained with hematoxylin and eosin for examining the microscopic and morphometric alterations and protective potential of Vit E. Data were analyzed using ANOVA.

RESULTS

Experimental animals treated with MPH showed a significant decrease in the diameter of seminiferous tubules (296.86 ± 14.70 µm) and height of germinal epithelium (51.73 ± 3.15 µm) with a corresponding gain in the thickness of the interstitium (47.05 ± 4.94 µm). Animals treated with MPH + Vit E did not reveal any significant testicular microscopic changes and seminiferous tubular alterations induced by MPH.

CONCLUSION

Vit E demonstrated a protective potential against the adverse changes induced by MPH in the male gonads in albino rats.

Overuse of methylphenidate: an analysis of Swedish pharmacy dispensing data

PURPOSE

To identify overuse of methylphenidate and to investigate patterns of overuse in relation to sociodemographic and clinical characteristics.

PATIENTS AND METHODS

Swedish national, pharmacy dispensing data were analyzed for all 56,922 individuals aged 6-79 years, who filled a methylphenidate prescription between 2010 and 2011. Overuse was defined as having above 150% days covered by the dispensed amount during 365 days from the first prescription fill, assuming use at the maximum recommended daily dose.

RESULTS

In total, 4,304 individuals (7.6% of the methylphenidate users) were categorized as overusers. The risk of overuse increased with age (OR for 46-65 years vs 6-12 years 17.5, 95% CI 14.3-21.3), and was higher in men (OR 1.4, 95% CI 1.3-1.5) and individuals with low income (OR 1.1, 95% CI 1.0-1.2), as well as in individuals with an attention deficit hyperactivity disorder (ADHD) diagnosis (OR 1.4, 95% CI 1.3-1.6), health care visits (OR 1.3, 95% CI 1.2-1.4), previous ADHD medication use (OR 2.6, 95% CI 2.4-2.8), and previous diagnosis of mental and behavioral disorders due to psychoactive substance use (OR 2.1 95% CI 2.0-2.3).

CONCLUSION

Among individuals using methylphenidate in Sweden, 7.6% receive amounts that are larger than what they should have a medical need for, assuming that they were using the maximum recommended daily dose 365 days per year. Notably, the prevalence of overuse was associated with previous diagnosis of alcohol and drug misuse. The prevalence was also positively associated with higher age and previous use of ADHD medication. These findings may point toward a link between exposure time and overuse. However, future studies with long-term data are needed to investigate this.

The Decrease in Human Endogenous Retrovirus-H Activity Runs in Parallel with Improvement in ADHD Symptoms in Patients Undergoing Methylphenidate Therapy

Increasing scientific evidence demonstrated the deregulation of human endogenous retroviruses (HERVs) expression in complex diseases, such as cancer, autoimmune, psychiatric, and neurological disorders. The dynamic regulation of HERV activity and their responsiveness to a variety of environmental stimuli designate HERVs as genetic elements that could be modulated by drugs. Methylphenidate (MPH) is widely used in the treatment of attention deficit hyperactivity disorder (ADHD). The aim of this study was to evaluate the time course of human endogenous retrovirus H (HERV-H) expression in peripheral blood mononuclear cells (PBMCs) with respect to clinical response in ADHD patients undergoing MPH therapy. A fast reduction in HERV-H activity in ADHD patients undergoing MPH therapy was observed in parallel with an improvement in clinical symptoms. Moreover, when PBMCs from drug-naïve patients were cultured in vitro, HERV-H expression increased, while no changes in the expression levels were found in ADHD patients undergoing therapy. This suggests that MPH could affect the HERV-H activity and supports the hypothesis that high expression levels of HERV-H could be considered a distinctive trait of ADHD patients.

Effects of neurofeedback versus methylphenidate for the treatment of attention-deficit/hyperactivity disorder protocol for a systematic review and meta-analysis of head-to-head trials

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is developmental disorder characterized by inattention and/or hyperactivity/impulsivity. Psychostimulants, including methylphenidate (MPH), are recommended as a first-line pharmacological intervention, whereas neurofeedback (NF) has been proposed as a nonpharmacological option. The comparative effects of MPH and NF need further exploration. We will conduct a systematic review and meta-analysis of head-to-head randomized controlled trials (RCTs) comparing the efficacy and/or tolerability of MPH and NF in children/adolescents and adults with ADHD.

METHOD AND ANALYSIS

We will include published as well as unpublished data. Two investigators will independently search PubMed, OVID, ERIC, Web of Science, ClinialTrials.gov, and a set of Chinese databases, including CNKI, CQVIP, and WanFang for head-to-head RCTs comparing MPH and NF. Experts will be contacted for unpublished data. The primary outcome will be the efficacy on ADHD core symptoms, measured by the change in the severity of ADHD symptoms, from baseline to endpoint and, if available, at follow-up (at any available time point). Secondary outcomes will be: dropouts for any reasons; efficacy on neuropsychological measures (working memory, inattention, and inhibition). We will conduct subgroup analyses to assess the impact of the following variables: age; type of NF; language of publication; comorbidities. Additionally, we will carry out meta-regression analyses to investigate the effect of sponsorship, year of publication, duration of intervention, and age of participants. Sensitivity analyses will be conducted to test the robustness of the findings. Risk of bias of individual studies will be assessed using the Cochrane risk of bias tool. Analyses will be performed using Comprehensive Meta-Analysis Software.

ETHICS AND DISSEMINATION

No ethical issues are foreseen. Results from this study will be published in a peer-reviewed journal and presented at relevant national and international conferences.

TRIALS REGISTRATION NUMBER

PROSPERO CRD42018090256.

Hallucinations and other psychotic symptoms in response to methylphenidate in children and adolescents with attention-deficit/hyperactivity disorder: a Cochrane systematic review with meta-analysis and trial sequential analysis. Scand J Child Adolesc Psychiatr Psychol 2018;6:52-71. [PMID: 33520751 PMCID: PMC7750702 DOI: 10.21307/sjcapp-2018-003]

BACKGROUND

There is little evidence in the literature on the association between methylphenidate treatment and psychotic symptoms in children and adolescents with attention-deficit/hyperactivity disorder (ADHD).

OBJECTIVE

We examine the occurrence of psychotic symptoms during methylphenidate treatment of children and adolescents with ADHD. The data arise from our two Cochrane systematic reviews on methylphenidate, reported elsewhere.

METHODS

Electronic databases were searched up to January 2016 (for observational studies) and March 2017 (for randomized trials). We summarized data as risk ratios and pooled prevalences. Trial Sequential Analysis was used to control for random errors. We assessed the risk of bias and the quality of evidence according to Cochrane guidelines.

RESULTS

Ten randomized trials (1103 participants), 17 non-randomized studies (76,237 participants) and 12 patient reports or series (18 patients) were identified. In the randomized trials, there was no significant difference in the risk of developing psychotic symptoms [10 of 654 (pooled prevalence, 2.5%) methylphenidate versus 1 of 508 (pooled prevalence, 1.7%) placebo patients; risk ratio, 2.07; 95% confidence interval, 0.58 to 7.35]. Nine of 10 trials had a high risk of bias, and according to the Trial Sequential Analysis, the required information size was not achieved, that is, the meta-analysis was considerably underpowered. There were 873 instances of psychotic symptoms in the non-randomized studies among 55,603 participants (pooled prevalence, 1.2%; 95% confidence interval, 0.7 to 2.4). In the comparative cohort study, methylphenidate significantly increased the risk for any psychotic disorder by 36% (risk ratio, 1.36; 95% confidence interval, 1.17 to 1.57). The overall risk of bias was rated as critical for this study.

CONCLUSIONS

Because of sparse data and low quality of evidence, we cannot confirm or refute whether methylphenidate increases the risk of psychotic symptoms in children and adolescents with ADHD. This possible adverse event may affect 1.1% to 2.5%, and physicians, patients and caregivers should be aware of this to ensure proper treatment in case of occurrence during methylphenidate treatment.

Aluminium adjuvants used in vaccines

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the benefits and harms of aluminium adjuvants used in a vaccine or an excipient versus the same vaccine or excipient, but having a different type of aluminium adjuvant formulation, or a different concentration, or with a different particle size.

Training, executive, attention and motor skills (TEAMS) training versus standard treatment for preschool children with attention deficit hyperactivity disorder: a randomised clinical trial

Objective

This study compared the effectiveness of manualised training, executive, attention, and motor skills (TEAMS) training versus standard treatment in preschool children with attention deficit hyperactivity disorder (ADHD). We conducted a randomised parallel group, single-blinded, superiority trial. The primary outcome was ADHD symptoms and the secondary outcome was functionality. Parents and primary school teachers assessed outcomes at pretreatment, posttreatment, and at one, three, and 6 months follow-up.

Results

In total, 67 children (aged 3–6 years) were randomised. In the TEAMS group, 32 out of 33 (97%) participants completed the total 8-week program, compared with only 7 out of 26 (27%) in the control group. The repeated-model analyses showed no significant change between the two interventions for ADHD symptoms and functionality levels over time. The mean difference in ADHD symptoms between TEAMS versus standard treatment at posttreatment was 2.18 points (95% confidence interval − 8.62 to 13.0; trial sequential analysis-adjusted confidence interval − 19.3 to 23.7).

Trial registration Clinical Trials identifier: NCT01918436 (Retrospectively registered). Registered on 7 August 2013.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3478-3) contains supplementary material, which is available to authorized users.

Gastrointestinal adverse events during methylphenidate treatment of children and adolescents with attention deficit hyperactivity disorder: A systematic review with meta-analysis and Trial Sequential Analysis of randomised clinical trials

OBJECTIVES

To study in more depth the relationship between type, dose, or duration of methylphenidate offered to children and adolescents with attention deficit hyperactivity disorder and their risks of gastrointestinal adverse events based on our Cochrane systematic review.

METHODS AND FINDINGS

We use data from our review including 185 randomised clinical trials. Randomised parallel-group trials and cross-over trials reporting gastrointestinal adverse events associated with methylphenidate were included. Data were extracted and quality assessed according to Cochrane guidelines. Data were summarised as risk ratios (RR) with 95% confidence intervals (CI) using the inverse variance method. Bias risks were assessed according to domains. Trial Sequential Analysis (TSA) was used to control random errors. Eighteen parallel group trials and 43 cross-over trials reported gastrointestinal adverse events. All trials were at high risk of bias. In parallel group trials, methylphenidate decreased appetite (RR 3.66, 95% CI 2.56 to 5.23) and weight (RR 3.89, 95% CI 1.43 to 10.59). In cross-over trials, methylphenidate increased abdominal pain (RR 1.61, 95% CI 1.27 to 2.04). We found no significant differences in the risk according to type, dose, or duration of administration. The required information size was achieved in three out of four outcomes.

CONCLUSION

Methylphenidate increases the risks of decreased appetite, weight loss, and abdominal pain in children and adolescents with attention deficit hyperactivity disorder. No differences in the risks of gastrointestinal adverse events according to type, dose, or duration of administration were found.

Methylphenidate for attention-deficit/hyperactivity disorder in children and adolescents: Cochrane systematic review with meta-analyses and trial sequential analyses of randomised clinical trials

STUDY QUESTION

Is methylphenidate beneficial or harmful for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents?

METHODS

Electronic databases were searched up to February 2015 for parallel and crossover randomised clinical trials comparing methylphenidate with placebo or no intervention in children and adolescents with ADHD. Meta-analyses and trial sequential analyses (TSA) were conducted. Quality was assessed using GRADE. Teachers, parents, and observers rated ADHD symptoms and general behaviour.

STUDY ANSWER AND LIMITATIONS

The analyses included 38 parallel group trials (n=5111, median treatment duration 49 days) and 147 crossover trials (n=7134, 14 days). The average age across all studies was 9.7 years. The analysis suggested a beneficial effect of methylphenidate on teacher rated symptoms in 19 parallel group trials (standardised mean difference (SMD) -0.77, n=1698), corresponding to a mean difference of -9.6 points on the ADHD rating scale. There was no evidence that methylphenidate was associated with an increase in serious adverse events (risk ratio 0.98, nine trials, n=1532; TSA adjusted intervention effect RR 0.91). Methylphenidate was associated with an increased risk of non-serious adverse events (1.29, 21 trials, n=3132; TSA adjusted RR 1.29). Teacher rated general behaviour seemed to improve with methylphenidate (SMD -0.87, five trials, n=668) A change of 7 points on the child health questionnaire (CHQ) has been deemed a minimal clinically relevant difference. The change reported in a meta-analysis of three trials corresponds to a mean difference of 8.0 points on the CHQ (range 0-100 points), which suggests that methylphenidate may improve parent reported quality of life (SMD 0.61, three trials, n=514). 96.8% of trials were considered high risk of bias trials according to the Cochrane guidelines. All outcomes were assessed very low quality according to GRADE.

WHAT THIS STUDY ADDS

The results suggest that among children and adolescents with a diagnosis of ADHD, methylphenidate may improve teacher reported symptoms of ADHD and general behaviour and parent reported quality of life. However, given the risk of bias in the included studies, and the very low quality of outcomes, the magnitude of the effects is uncertain. Methylphenidate is associated with an increased risk of non-serious but not serious adverse events.

FUNDING, COMPETING INTERESTS, DATA SHARING

Region Zealand Research Foundation and Copenhagen Trial Unit. Competing interests are given in the full paper on bmj.com. Full data are available in the version of this review published in The Cochrane Library.

Does Methylphenidate Affect Cystometric Parameters in Spontaneously Hypertensive Rats?

PURPOSE

Methylphenidate (MPH) is one of the most commonly prescribed psychostimulants for attention deficit hyperactivity disorder (ADHD). However, there is limited research on its effects on lower urinary tract function. This study investigated changes in cystometric parameters after intragastric administration of MPH in conscious spontaneously hypertensive rats (SHRs), an animal model of ADHD.

METHODS

Fourteen- to 16-week-old male SHRs (n=10), weighing between 280 and 315 g, were used. Three micturition cycles were recorded before administering MPH. One hour after each intragastric MPH injection, three cycles of cystometrogram were obtained in the awake condition. Various cystometric parameters were evaluated, including basal pressure (BP), maximal pressure (MP), threshold pressure (TP), bladder capacity (BC), micturition volume (MV), micturition interval (MI), and residual volume (RV). The data were analyzed using paired Student t-tests.

RESULTS

Five SHRs were each administered a dose of 3-mg/kg MPH, and the other five received a dose of 6-mg/kg MPH. BP and MP increased significantly in the rats that received the 3-mg/kg MPH injection, but not in those that received the 6-mg/kg injection. BC, MV, and MI significantly increased in the rats that received the 6-mg/kg MPH injection, but not in those that received the 3-mg/kg injection. There were no significant changes in TP after either injection.

CONCLUSIONS

Significant increases in BC, MV, and MI after the 6-mg/kg MPH injection suggest that the peripheral and the central nervous systems may play important roles in bladder function in those receiving MPH for ADHD.