Cardiovascular Effects of Methylphenidate, Amphetamines and Atomoxetine in the Treatment of Attention-Deficit Hyperactivity Disorder: An Update

Captagon-induced Brugada phenocopy: A report of two cases

Brugada phenocopies (BrP) represent electrocardiogram changes identical to those of true congenital Brugada syndrome but are induced by reversible clinical conditions. Previous cases have been reported in patients following recreational drug use. This report presents two cases of type 1B BrP associated with Fenethylline abuse, a recreational drug known by its trade name, Captagon.

Effects of methylphenidate on blood pressure, QT-interval, and cardiac output in ADHD diagnosed children: A three months' follow-up study

BACKGROUND

Attention-deficit hyperactivity disorder (ADHD) is one of the most prevalent psychiatric disorders of childhood. It's been suggested that both the condition and the medications used to treat it can affect the cardiovascular system. This study aims to determine whether methylphenidate has the significant effects in cardiac indices.

METHODS

In this prospective study, 100 newly ADHD-diagnosed children aged 6 to 11 whom all on methylphenidate were included. The demographic, clinical data including the blood pressure and heart rate (HR), echocardiographic, and QT-interval were recorded at baseline and after three months of follow-up.

RESULTS

After the follow-up period, we observed no abnormal systolic, diastolic, or mean arterial pressure in any of the participants based on their age, height, and gender (p < 0.001). However, the mean of all these variables was significantly increased (p 〈0 0 1). Mean pulse pressure was also higher than baseline but it wasn't statistically significant (p = 0.059). No significant change was observed in echocardiographic parameters and QT.

CONCLUSION

Short-term treatment of ADHD in children with methylphenidate does not have a meaningful relationship with hypertension and increased corrected QT interval. However, an increase in blood pressure and corrected QT interval within a non-pathological range suggests that longer follow-ups may reveal an association.

Long-term cardiovascular safety of psychostimulants in children with attention deficit hyperactivity disorder

Objective: Side effects are a concern during psychostimulant treatment. Unfortunately, many previous studies only investigated short-term effects of psychostimulants in laboratory settings which lack clinical daily routines. Methods: We examined 1042 patient records of patients with attention deficit hyperactivity disorder (ADHD) who were referred to a pediatric-psychiatry practice over 12 years. Data analysis was based on 466 children with ADHD who were newly treated with psychostimulants and who were not in treatment for elevated blood pressure. We analysed blood pressure percentiles, heart rate and BMI percentiles. Results: There was a decrease in systolic and diastolic blood pressure percentiles. Heart rate was not affected. BMI slightly declined in girls. Conclusions: In general psychostimulants were safe. To further elucidate negative effects of psychostimulants, long-term controlled and randomized studies in naturalistic settings are of interest.

Drug-drug interactions and clinical considerations with co-administration of antiretrovirals and psychotropic drugs

Psychotropic medications are frequently co-prescribed with antiretroviral therapy (ART), owing to a high prevalence of psychiatric illness within the population living with HIV, as well as a 7-fold increased risk of HIV infection among patients with psychiatric illness. While ART has been notoriously associated with a multitude of pharmacokinetic drug interactions involving the cytochrome P450 enzyme system, the magnitude and clinical impact of these interactions with psychotropics may range from negligible effects on plasma concentrations to life-threatening torsades de pointes or respiratory depression. This comprehensive review summarizes the currently available information regarding drug-drug interactions between antiretrovirals and pharmacologic agents utilized in the treatment of psychiatric disorders-antidepressants, stimulants, antipsychotics, anxiolytics, mood stabilizers, and treatments for opioid use disorder and alcohol use disorder-and provides recommendations for their management. Additionally, overlapping toxicities between antiretrovirals and the psychotropic classes are highlighted. Knowledge of the interaction and adverse effect potential of specific antiretrovirals and psychotropics will allow clinicians to make informed prescribing decisions to better promote the health and wellness of this high-risk population.

A randomized controlled laboratory study on the long-term effects of methylphenidate on cardiovascular function and structure in rhesus monkeys

BACKGROUND

Whether long-term methylphenidate (MPH) results in any changes in cardiovascular function or structure can only be properly addressed through a randomized trial using an animal model which permits elevated dosing over an extended period of time.

METHODS

We studied 28 male rhesus monkeys (Macaca mulatta) approximately 7 years of age that had been randomly assigned to one of three MPH dosages: vehicle control (0 mg/kg, b.i.d., n = 9), low dose (2.5 mg/kg, b.i.d., n = 9), or high dose (12.5 mg/kg, b.i.d., n = 10). Dosage groups were compared on serum cardiovascular and inflammatory biomarkers, electrocardiograms (ECGs), echocardiograms, myocardial biopsies, and clinical pathology parameters following 5 years of uninterrupted dosing.

RESULTS

With the exception of serum myoglobin, there were no statistical differences or apparent dose-response trends in clinical pathology, cardiac inflammatory biomarkers, ECGs, echocardiograms, or myocardial biopsies. The high-dose MPH group had a lower serum myoglobin concentration (979 ng/mL) than either the low-dose group (1882 ng/mL) or the control group (2182 ng/mL). The dose response was inversely proportional to dosage (P = .0006).

CONCLUSIONS

Although the findings cannot be directly generalized to humans, chronic MPH exposure is unlikely to be associated with increased cardiovascular risk in healthy children.

Effects of Long-Term Use of Prescription Methylphenidate on Myocardial Performance in Children with Attention-Deficit/Hyperactivity Disorder: A Tissue Doppler Imaging Study

OBJECTIVE

Many children diagnosed with attention-deficit/hyperactivity disorder are treated with methylphenidate (MPH). The purpose of this study was to evaluate the relationship between long-term use of osmotic-release oral system methylphenidate (OROS MPH) and cardiac functions.

METHODS

The study involved 116 subjects 6-18 years of age. Fifty-eight of these were in the case group and were using OROS MPH (extended-release capsules). Fifty-eight children not receiving treatment were included in the control group. Participants were also assessed using 12-channel electrocardiography (ECG), transthoracic 2D echocardiography, Doppler echocardiography, and tissue Doppler imaging (TDI). The findings obtained were compared using statistical methods.

RESULTS

No significant differences were determined between the case and control groups in terms of systolic blood pressure and diastolic blood pressure or 12-channel ECG findings. There was also no difference in 2D and M-mode measurements among the echocardiography findings. Of the TDI parameters obtained, only E' septal values differed significantly between the case and control groups. However, this was not at such a level as to indicate cardiac function impairment.

CONCLUSIONS

The study data showed that the echocardiographic parameters we measured resulted in no clinical difference between the children using MPH and the healthy controls. We conclude that MPH use in children does not impair cardiovascular functions at short-term follow-up.

Cardiovascular Effects of Drugs Used to Treat Attention-Deficit/Hyperactivity Disorder: Part 1: Epidemiology, Pharmacology, and Impact on Hemodynamics and Ventricular Repolarization

Attention-deficit/hyperactivity disorder (ADHD) is a clinical syndrome characterized by persistent inattention, impulsivity, and hyperactivity. It is most commonly encountered in children and adolescents but may persist into adulthood. A variety of psychostimulant and nonpsychostimulant medications have proven to be successful in reducing inattention, impulsivity, and hyperactivity in those with ADHD. Psychostimulants used to treat ADHD include methylphenidate and related drugs and various amphetamine preparations. Non-psychostimulant medications used to treat ADHD include atomoxetine and two alpha-2 adrenergic agonists: guanfacine extended-release and clonidine extended-release. The psychostimulants and atomoxetine have been shown, on average, to increase heart rate by 3-10 beats/min, systolic blood pressure by 3-8 mm Hg, and diastolic blood pressure by 2-14 mm Hg. These drugs may also delay ventricular repolarization. The alpha-2 adrenergic agonists may reduce heart rate and blood pressure. For these reasons, there is concern about the safety of psychostimulant and nonpsychostimulant medications in patients with ADHD. In part 1 of this review, we discuss the epidemiology and natural history of ADHD, describe the pharmacology of drugs used to treat ADHD, and discuss in detail studies assessing the effects of ADHD drugs on blood pressure, heart or pulse rate, and electrocardiographic indices of ventricular repolarization.

Effects of long-term methylphenidate use on growth and blood pressure: results of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS)

BACKGROUND

Concerns have been raised over the safety of methylphenidate (MPH), with regard to adverse effects on growth and blood pressure. Our study investigates whether, and to what extent, methylphenidate use in boys with ADHD is associated with having low body mass index (BMI), having low height, and increased systolic and diastolic blood pressure.

METHODS

Data used for this study stem from the German KiGGS dataset. Three different groups of boys aged 6-15 years were included in the analysis: ADHD patients who used MPH for less than 12 months; ADHD patients who used MPH for 12 months or more; and ADHD patients without current MPH treatment. Each of these three groups was compared to a non-ADHD control group regarding low weight (BMI ≤ 3rd percentile), low height (≤3rd percentile) and raised systolic and diastolic blood pressure. For growth outcomes, boys were categorized according to age (< 11 years/≥11 years, to account for pubertal maturation). Multivariable logistic regression was conducted to test for associations.

RESULTS

4244 boys were included in the study; MPH < 12 months: n = 65 (n = 36 < 11 years), MPH ≥ 12 months: n = 53 (n = 22 < 11 years), ADHD controls: n = 320 (n = 132 < 11 years), non-ADHD controls: n = 3806 (n = 2003 < 11 years). Pre-pubertal boys with MPH use less than 12 months and pubertal/postpubertal boys with MPH use of 12 months or greater were significantly more likely to have a BMI ≤ 3rd percentile compared to non-ADHD controls. Boys from the ADHD control group were significantly less likely to have a raised systolic blood pressure compared to non-ADHD controls. Beyond that, no significant between group differences were observed for any other growth and BP parameter.

CONCLUSION

The analyses of the KiGGS dataset showed that MPH use in boys with ADHD is associated with low BMI. However, this effect was only observed in certain groups. Furthermore, our analysis was unable to confirm that MPH use is also associated with low height (≤3rd percentile) and changes in blood pressure.

The Effect of Methylphenidate and Atomoxetine on Heart Rate and Systolic Blood Pressure in Young People and Adults with Attention-Deficit Hyperactivity Disorder (ADHD): Systematic Review, Meta-Analysis, and Meta-Regression

Objectives: This meta-analysis aims to study the effects of atomoxetine and methylphenidate on heart rate (HR), systolic blood pressure (SBP), and a number of adverse cardiac events on patients receiving treatment for attention-deficit hyperactive disorder (ADHD) in comparison to placebo and between atomoxetine and methylphenidate. Methods: We searched the following databases: PubMed, EMBASE, and ScienceDirect. Meta-analysis was performed on studies that examined the relationships between methylphenidate or atomoxetine and HR, SBP, as well as a number of adverse cardiac events. These studies were either placebo-controlled or comparison studies between methylphenidate and atomoxetine. Meta-regression identified patient- and treatment-related factors that may contribute to heterogeneity. Results: Twenty-two studies were included and the total number of participants was 46,107. Children/adolescents and adults treated with methylphenidate had more significant increases in post- vs. pre-treatment HR (p < 0.001) and SBP (p < 0.001) than those treated by placebo. Children and adolescents treated with atomoxetine had more significant increases post- vs. pre-treatment HR (p = 0.025) and SBP (p < 0.001) than those treated with methylphenidate. Meta-regression revealed mean age of participants, mean dose, and duration of atomoxetine and methylphenidate as significant moderators that explained heterogeneity. There were no differences in the number of adverse cardiac events between participants with methylphenidate treatment and placebo or atomoxetine. Conclusions: Children/adolescents and adults treated with methylphenidate resulted in significant increases in post- vs. pre-treatment HR and SBP as compared to placebo. Similarly, children and adolescents treated with atomoxetine had significant increases in post- vs. pre-treatment HR and SBP than those treated with methylphenidate. These findings have potential implications for continuous monitoring of HR and SBP throughout the course of treatment although the risk for adverse cardiac events were insignificant.

Mining Patients' Narratives in Social Media for Pharmacovigilance: Adverse Effects and Misuse of Methylphenidate

Background: The Food and Drug Administration (FDA) in the United States and the European Medicines Agency (EMA) have recognized social media as a new data source to strengthen their activities regarding drug safety.

Objective: Our objective in the ADR-PRISM project was to provide text mining and visualization tools to explore a corpus of posts extracted from social media. We evaluated this approach on a corpus of 21 million posts from five patient forums, and conducted a qualitative analysis of the data available on methylphenidate in this corpus.

Methods: We applied text mining methods based on named entity recognition and relation extraction in the corpus, followed by signal detection using proportional reporting ratio (PRR). We also used topic modeling based on the Correlated Topic Model to obtain the list of the matics in the corpus and classify the messages based on their topics.

Results: We automatically identified 3443 posts about methylphenidate published between 2007 and 2016, among which 61 adverse drug reactions (ADR) were automatically detected. Two pharmacovigilance experts evaluated manually the quality of automatic identification, and a f-measure of 0.57 was reached. Patient's reports were mainly neuro-psychiatric effects. Applying PRR, 67% of the ADRs were signals, including most of the neuro-psychiatric symptoms but also palpitations. Topic modeling showed that the most represented topics were related to Childhood and Treatment initiation, but also Side effects. Cases of misuse were also identified in this corpus, including recreational use and abuse.

Conclusion: Named entity recognition combined with signal detection and topic modeling have demonstrated their complementarity in mining social media data. An in-depth analysis focused on methylphenidate showed that this approach was able to detect potential signals and to provide better understanding of patients' behaviors regarding drugs, including misuse.

Blood pressure in children with attention deficit/hyperactivity disorder

Objectives

Children with attention deficit/hyperactivity disorder (ADHD) are frequently treated with psycho-stimulant agents causing a modest but significant increase in blood pressure and heart rate. The objective of this study was to define blood pressure characteristics in children with ADHD treated with a variety of medications in a community setup.

Methods

Children registered at a large paediatric clinic in Calgary, AB with documented histories of ADHD were randomly contacted. Consenting participants had standardized office BP measurements, ambulatory blood pressure monitoring (ABPM) studies and were asked to complete the sleep disturbance scale for children (SDSC) questionnaire. Findings were compared with data from the Canadian Health Measures Survey (CMHS).

Results

Fifty-five children (47 males) aged 7 to 17 years (average 11.6 ± 2.5 years) with an average BMI z-score of -0.37 ± 1.22 completed the study. All children were medicated, the majority (82%), with various types of stimulant agents. Elevated office BP values were more prevalent than in the CMHS; >90th percentile in 5 (9.1%) and >95th percentile in 3 (5.5%). ABPM confirmed 'white coat hypertension' in 3 (5.5%), masked hypertension in 2 (3.6%) and nondipping in 28 (51%). The SDSC score suggested that 43 (78%) children had disturbed sleep. Logistic regression modelling indicated that nondipping correlated with disturbed sleep.

Conclusion

The 'white coat' phenomenon may be responsible for increased prevalence of elevated rest/office BP values in children with ADHD. Prevalent sleep 'non-dipping' in this population is associated with sleep disturbances but clinical significance of this finding requires further investigation.

Potential Effect of Pharmacotherapy on Sympathetic Arousal in Autism

Background: Autism spectrum disorder (ASD) is a serious neurodevelopmental disorder associated with autonomic nervous system (ANS) abnormalities. Moreover, at least 50% of children with ASD suffer from other comorbid diseases such as anxiety, depression, and attention deficit hyperactivity disorder (ADHD) associated with receiving psychotropic medication. From this context we aimed to evaluate changes in sympathetic arousal using analysis of electrodermal activity (EDA) as an index of sympathetic cholinergic activity in treated and non-treated autistic children under resting conditions.

Methods: We examined 23 children with ASD and 14 healthy age- and gender-matched children at the age of 7–15 years. The ASD patients were divided into ASD non-treated group (n=12) and ASD treated group (n=11). The EDA was continuously monitored during resting phase in a supine position. The EDA amplitude (μS) was computed as an average of 5 min baseline period.

Results: We found significantly lower EDA in ASD non-treated subgroup compared to controls indicating subtle abnormalities in the regulation of the sympathetic nervous system. Although no significant differences were found between the ASD treated and non-treated subgroups the ASD treated group showed comparable sympathetic activity relative to controls indicating a potential ameliorated treatment effect on sympathetic arousal in ASD.

Conclusions: These findings could help to determine differences in sympathetic arousal in treated and non-treated children with ASD, which is important for assessment of autism-linked cardiovascular risk depending on pharmacotherapy.

The safety of extended-release drug formulations for the treatment of ADHD

INTRODUCTION

Attention-deficit/hyperactivity disorder (ADHD) is a complex neurobehavioral disorder affecting millions of patients worldwide. Effective treatments have been available for more than 60 years in the form of immediate-release (IR) stimulants However, stimulants have a high risk for abuse and are associated with adverse effects Including elevated blood pressure and heart rate, insomnia and decreased appetite. IR formulations also require multiple daily dosing. The search for improved safety, tolerability and convenience has led to the development of multiple extended-release (ER) stimulant and non-stimulant formulations. Areas covered: Adverse effects of (ER) products including amphetamine, methylphenidate, clonidine and guanfacine will be reviewed and their significance discussed. Expert opinion: Limitations of currently marketed medications have led to the search for drugs with efficacy comparable to ER stimulants and a more favorable adverse event profile. Several are in development, but their potential utility is not yet known. Current research is also focused on finding specific genetic defects in patients with ADHD. Exciting progress has been made with the identification of mGluR receptor defects in some patients. However because of the heterogeneity of the disorder, effective targeted treatments for the majority of patients with ADHD does not appear likely in the near future.

Cardiovascular Complications of Acute Amphetamine Abuse: Cross-sectional study

OBJECTIVES

This study aimed to evaluate cardiovascular complications among patients who abuse amphetamines.

METHODS

This cross-sectional study took place between April 2014 and April 2015 among 3,870 patients referred to the Toxicology Emergency Department of Baharlou Hospital, Tehran University of Medical Sciences, Tehran, Iran. Those with clinical signs of drug abuse and positive urine screening tests were included in the study, while cases of chronic abuse were excluded. Cardiac complications were evaluated via electrocardiography (ECG) and transthoracic echocardiography.

RESULTS

A total of 230 patients (5.9%) had a history of acute amphetamine abuse and positive urine tests. Of these, 32 patients (13.9%) were <20 years old and 196 (85.2%) were male. In total, 119 (51.7%) used amphetamine and methamphetamine compounds while 111 (48.3%) used amphetamines with morphine or benzodiazepines. The most common ECG finding was sinus tachycardia (43.0%), followed by sinus tachycardia plus a prolonged QT interval (34.3%). Mean creatine kinase-MB and troponin I levels were 35.9 ± 4.3 U/mL and 0.6 ± 0.2 ng/mL, respectively. A total of 60 patients (26.1%) were admitted to the Intensive Care Unit. The majority (83.3%) of these patients had normal echocardiography results. The mean aortic root diameter (ARD) was 27.2 ± 2.8 mm. Abnormalities related to the ARD were found in 10 patients (16.7%), three of whom subsequently died.

CONCLUSION

According to these findings, cardiac complications were common among Iranian patients who abuse amphetamines, although the majority of patients had normal echocardiography and ECG findings.

Electrocardiogram before starting stimulant medications: to order or not?

D is an 8-year-old boy brought to his paediatrician for evaluation. His mother is concerned as his teacher has been frequently complaining that he is very restless and often disturbs the rest of the class by getting up on some pretext or the other. He is unable to concentrate on his work and gets distracted very easily. He makes many careless mistakes and can hardly finish his tasks on time. He is frequently reprimanded for talking during class. He often answers out of turn or before the question has been completed; however, so far, he has been managing to get passing grades. At home, he is constantly on the go while he is awake. If he is forced to sit, like at mealtimes, he fidgets a lot. He also needs to be constantly nagged to do everything, even his daily activities such as brushing his teeth, or he forgets to do them or leaves them incomplete. He takes ages to finish his food. It is a major job to get him to do his homework. His mother says that at home he has been like that since the last 2 to 3 years, but now she is concerned because of the difficulties he is experiencing at school as well. After obtaining his medical history, examination, and getting response from parents and teachers--using Vanderbuilt Assessment Scales--the paediatrician diagnoses him to have attention deficit hyperactivity disorder. Besides behavioural interventions, he considers medications for his management. The paediatrician is debating the merits of performing electrocardiogram and/or referring the boy to a cardiologist before starting stimulant medications. If you were caring for this patient, how would you proceed?

Modafinil May Alleviate Poststroke Fatigue: A Randomized, Placebo-Controlled, Double-Blinded Trial

BACKGROUND AND PURPOSE

Poststroke fatigue is common and reduces quality of life. Current evidence for intervention is limited, and this is the first placebo-controlled trial to investigate treatment of poststroke fatigue with the wakefulness promoting drug modafinil.

METHODS

The trial was randomized, double-blinded, and placebo-controlled. Patients were treated with 400-mg modafinil or placebo for 90 days. Assessments were done at inclusion, 30, 90, and 180 days. The primary end point was fatigue at 90 days measured by the Multidimensional Fatigue Inventory-20 general fatigue domain. Secondary end points included the Fatigue Severity Scale, the Montreal Cognitive Assessment, the modified Rankin Scale and the Stroke-specific quality of Life questionnaire. Adult patients with a recent stroke achieving a score of ≥12 on the Multidimensional Fatigue Inventory-20 general fatigue domain were consecutively included. Exclusion criteria were severe cognitive disabilities and contraindications for modafinil treatment.

RESULTS

One thousand one hundred twenty-one patients with stroke were screened and 41 patients included, 21 received modafinil. The primary end point, the Multidimensional Fatigue Inventory-20 general fatigue score, did not differ between groups. Patients in the modafinil group obtained better scores on the Fatigue Severity Scale (P=0.02) and in some subscales of the stroke-specific quality of life questionnaire (0.001<P<0.05), which were secondary outcomes. No serious adverse reactions were observed and there was no difference in blood pressure between groups.

CONCLUSIONS

There were no significant differences between the 2 groups with regard to the primary end point. There were secondary significant outcomes that should be explored in future trials.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01800097.

Unmet needs in paediatric psychopharmacology: Present scenario and future perspectives

Paediatric psychopharmacology holds great promise in two equally important areas of enormous biomedical and social impact, namely the treatment of behavioural abnormalities in children and adolescents, and the prevention of psychiatric disorders with adolescent- or adult-onset. Yet, in striking contrast, pharmacological treatment options presently available in child and adolescent psychiatry are dramatically limited. The most important currently unmet needs in paediatric psychopharmacology are: the frequent off-label prescription of medications to children and adolescents based exclusively on data from randomized controlled studies involving adult patients; the frequent lack of age-specific dose, long-term efficacy and tolerability/safety data; the lack of effective medications for many paediatric psychiatric disorders, most critically autism spectrum disorder; the scarcity and limitations of randomized placebo-controlled trials in paediatric psychopharmacology; the unexplored potential for the prevention of psychiatric disorders with adolescent- and adult-onset; the current lack of biomarkers to predict treatment response and severe adverse effects; the need for better preclinical data to foster the successful development of novel drug therapies; and the effective dissemination of evidence-based treatments to the general public, to better inform patients and families of the benefits and risks of pharmacological interventions during development. Priorities and strategies are proposed to overcome some of these limitations, including the European Child and Adolescent Clinical Psychopharmacology Network, as an overarching Pan-European infrastructure aimed at reliably carrying out much needed psychopharmacological trials in children and adolescents, in order to fill the identified gaps and improve overall outcomes.

Changes of Heart Rate Variability during Methylphenidate Treatment in Attention-Deficit Hyperactivity Disorder Children: A 12-Week Prospective Study

PURPOSE

The aim of this study was to clarify the relationship between the autonomic nervous system and attention deficit hyperactivity disorder (ADHD) rating scales and to evaluate the usefulness of heart rate variability (HRV) as a psychophysiological biomarker for ADHD.

MATERIALS AND METHODS

Subjects were recruited from outpatients in the Department of Child and Adolescent Psychiatry at the Korea University Medical Center from August 2007 to December 2010. Subjects received methylphenidate. Time- and frequency-domain analyses of HRV, the Korean ADHD rating scale (K-ARS), and computerized ADHD diagnostic system were evaluated before treatment. After a 12-week period of medication administration, we repeated the HRV measurements and K-ARS rating.

RESULTS

Eighty-six subjects were initially enrolled and 37 participants completed the 12-week treatment and HRV measurements subsequent to the treatment. Significant correlations were found between the K-ARS inattention score and some HRV parameters. All of the HRV parameters, except the standard deviations of the normal-to-normal interval, very low frequency, and low frequency to high frequency, showed a significant positive correlation between baseline and endpoint measures in completers. High frequency (HF) and the square root of the mean squared differences of successive normal-to-normal intervals (RMSSD), which are related to parasympathetic vagal tone, showed significant decreases from baseline to endpoint.

CONCLUSION

The HRV test was shown to be reproducible. The decrease in HF and RMSSD suggests that parasympathetic dominance in ADHD can be altered by methylphenidate treatment. It also shows the possibility that HRV parameters can be used as psychophysiological markers in the treatment of ADHD.

Clinical utility of guanfacine extended release in the treatment of ADHD in children and adolescents

Attention deficit hyperactivity disorder (ADHD) is the most common psychiatric illness in children and adolescents. Several stimulant medications, such as methylphenidate and amphetamine derivatives, are available to treat ADHD in pediatric patients. Nonstimulant medications are more preferred by some parents, other caregivers, and patients because they lack the abuse potential of stimulant medications. In the US, one available nonstimulant option is guanfacine extended release (XR). As a selective α2A adrenergic receptor, guanfacine acts on the central noradrenergic pathways and cortical noradrenergic targets to improve working memory and attention. The XR formulation of guanfacine, compared with the immediate-release formulation, is more effective for the long-term management of ADHD and is associated with fewer adverse effects. Available data also indicate that guanfacine XR is superior to atomoxetine and is as effective as the nonselective α2 adrenergic receptor agonist, clonidine XR. The most common adverse effects associated with guanfacine XR are somnolence, fatigue, bradycardia, and hypotension. Somnolence is the most often cited reason for discontinuation. Guanfacine XR is also labeled for use as an adjuvant to stimulant treatment for ADHD. A similar profile of adverse effects as reported with monotherapy is reported when guanfacine XR is "added on" to stimulant therapy with somnolence as the most commonly reported adverse event. This review discusses the clinical efficacy and patient preference of guanfacine XR based on available published data on the safety, relative effectiveness, and tolerance of this medication to treat ADHD.

Evaluation of acute cardiovascular effects of immediate-release methylphenidate in children and adolescents with attention-deficit hyperactivity disorder

Attention-deficit hyperactivity disorder is a frequent condition in children and often extends into adulthood. Use of immediate-release methylphenidate (MPH) has raised concerns about potential cardiovascular adverse effects within a few hours after administration. This study was carried out to investigate acute effects of MPH on electrocardiogram (ECG) in a pediatric population. A total of 54 consecutive patients with attention-deficit hyperactivity disorder (51 males and 3 females; mean age =12.14±2.6 years, range 6-19 years), receiving a new prescription of MPH, underwent a standard ECG 2 hours before and after the administration of MPH 10 mg per os. Basal and posttreatment ECG parameters, including mean QT (QT interval when corrected for heart rate [QTc]), QTc dispersion (QTd) interval duration, T-peak to T-end (TpTe) intervals, and TpTe/QT ratio were compared. Significant modifications of both QTc and QTd values were not found after drug administration. QTd fluctuated slightly from 25.7±9.3 milliseconds to 25.1±8.4 milliseconds; QTc varied from 407.6±12.4 milliseconds to 409.8±12.7 milliseconds. A significant variation in blood pressure (systolic blood pressure 105.4±10.3 vs 109.6±11.5; P<0.05; diastolic blood pressure 59.2±7.1 vs 63.1±7.9; P<0.05) was observed, but all the data were within normal range. Heart rate moved from 80.5±15.5 bpm to 87.7±18.8 bpm. No change in TpTe values was found, but a statistically significant increase in TpTe/QTc intervals was found with respect to basal values (0.207±0.02 milliseconds vs 0.214±0.02 milliseconds; P<0.01). The findings of this study show no significant changes in ECG parameters. TpTe values can be an additional parameter to evaluate borderline cases.