Risques cardiovasculaires et conduite à tenir dans le traitement du trouble déficit de l’attention/hyperactivité avec le méthylphénidate

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common of the pediatric neuropsychiatric disorders. Methylphenidate is an important element of therapeutic strategies for ADHD. Clinicians are interested in the safety of methylphenidate. Because this drug raises heart rate and blood pressure, concerns have been raised about its cardiovascular safety. Concerns were based on case reports of sudden cardiac death in methylphenidate users, plausible pharmacological pathways involving well-established stimulant effects on heart rate and blood pressure. Until recently, data were limited to a number of observational studies too small to examine serious cardiac events. In the past two years, large retrospective, population-based cohort studies were performed. These studies did not show any evidence that methylphenidate was associated with an increase in risk of myocardial infarction, sudden cardiac death, or stroke. Treatment of children with methylphenidate is not significantly associated with an increase in the short term or mid-term risk of severe cardiac events. For many, available data now will be seen as reassuring. But gaps persist in the methodical and comprehensive assessments of the safety of methylphenidate. Analyses cannot be generalized to children with long-term use of stimulants. Furthermore, long-term effects of slight increases in heart rate or blood pressure are unknown. Stimulant administration continues to have a detectable adrenergic effect even after years of treatment. In the MTA study, greater cumulative stimulant exposure was associated with a higher heart rate at years 3 and 8. Although less severe, such adverse cardiac events are nonetheless alarming to patients. This adrenergic effect may have clinical implications, especially for individual patients with underlying heart abnormalities and it deserves further investigation. More research is necessary to optimize a safe use of methylphenidate regarding its cardiovascular effects. In light of the controversies surrounding the increase in the number of children being diagnosed with ADHD, the broad use of methylphenidate in these patients, and cardiovascular concerns about it, this article addresses topics of clinical significance. For ease of use by practitioners, the article summarizes the guidelines stated by the European Medicines Agency over the appropriate pretreatment evaluation and cardiovascular assessment. It advocates a thorough history and physical examination before initiating methylphenidate to treat patients with ADHD, with an emphasis on the identification of risk factors for sudden death. A cardiac sub-specialist consultation is mandatory in case of history or physical examination findings. In other cases, an electrocardiographic screening is recommended in order to check out previously unrecognized heart disease.     

Tricyclic antidepressant overdose

Overdose of a tricyclic antidepressant is a serious and all-too-frequent occurrence. The diagnosis must be considered in known or suspected overdoses, and signs such as a dry axilla, tachycardia, and wide QRS must be specifically sought. Management depends upon support of vital functions and a thorough understanding of the pharmacology of the drug. Emptying the gastrointestinal tract with ipecac or lavage and hastening elimination with activated charcoal and a cathartic are extremely important measures. Cardiac arrhythmias generally respond to sodium bicarbonate, and seizures respond to intravenous diazepam. Neither physostigmine nor dialysis are considered to be treatments of choice. As in other overdoses, counseling to prevent ingestions is more than worth "a pound of the cure."     

Tachykarde Herzrhythmusstörungen im Kindes- und Jugendalter

Paroxysmal supraventricular tachycardia (SVT) is the most common type of tachyarrhythmia occurring with an incidence of 0.1–0.4%. The occurrence of ventricular tachycardia is significantly lower in children and adults. The most frequent types of SVT in children are atrioventricular reentry tachycardia (AVRT) mediated by an accessory pathway and AV-nodal reentry tachycardia (AVNRT) using fibres with different conduction capacities (dual physiology of the AV-node). Both types can be successfully terminated with adenosine which selectively blocks conduction through the AV-node. Long-term pharmacological therapy represents one therapeutic option for recurrent episodes of SVT but it is increasingly being replaced by radiofrequency catheter ablation, which represents a curative treatment of SVT with success rates between 86% and 97%, especially when applied in children older than 5 years. Thus, long-term management of children with tachyarrhythmias should include early contact with pediatric electrophysiological centres.     

False-positive tricyclic antidepressant drug screen results leading to the diagnosis of carbamazepine intoxication

Ingestion of toxic substances is a common problem in pediatrics. When presented with the limited history of an unknown ingestion in a patient with altered mental status, a clinician depends on the physical examination and a toxic screen to determine the ingested substance(s). Some toxic screens yield false-positive or false-negative results that confound identification of ingested toxins. Three cases are presented in which carbamazepine ingestions were identified because of the false-positive tricyclic antidepressant serum toxic screen result in each case. Carbamazepine ingestion is one of the most common pediatric overdoses. Side effects include altered mental status, tachycardia, mydriasis, seizures, coma, and death. Several other substances also cause false-positive tricyclic antidepressant toxic screen results, including certain antipsychotic medications, antihistamines, and the muscle relaxant cyclobenzaprine. Specific tests and drugs causing false-positive results are presented in table form. More modern methods, specifically gas chromatographic-mass spectrometric, are more reliable in distinguishing these drugs. Knowledge of which substances commonly cause false-positive results on a given toxic screen can still lead the clinician to the correct diagnosis. tricyclic, carbamazepine, ingestion, intoxication, drug screen.     

Pediatric methylphenidate exposures: 7-year experience of poison centers in the United States

This study was undertaken to evaluate trends and toxicity of pediatric methylphenidate exposures; 1993 to 1999 national poison center data were analyzed. There were 12,917 exposures, increasing from 927 in 1993 to 2,445 in 1999. The majority of children during the entire study period experienced no effect (60.3%) or minor effects (28.7%), with no fatalities. Most common reasons were unintentional general or therapeutic errors in children under 13 years and suicide attempt in adolescents. Adolescents were more likely to experience clinical toxicity, hospitalizations and more serious outcomes. The trend of increasing frequency of methylphenidate exposures reported to poison centers exactly parallels increasing therapeutic use.     

Treating attention-deficit/hyperactivity disorder with a stimulant transdermal patch: the clinical art

Stimulant medications (amphetamine and methylphenidate) are the best-documented treatments for attention-deficit/hyperactivity disorder, but their short pharmacokinetic and behavioral half-lives have historically produced irksome time-course effects. New drug-delivery systems designed to eliminate the need for frequent dosing include the methylphenidate transdermal system, in which the matrix acts as both the drug reservoir and the skin adhesive. The methylphenidate transdermal system patch, in contrast to long-acting oral preparations, requires a paradigmatic shift in clinical thinking, as well as refinement of clinical management skills. For dosing with the methylphenidate transdermal system patch, clinicians must think in terms of a retrievable form of drug delivery (in milligrams per hour) rather than a fixed nonretrievable dose (in milligrams per dose or milligrams per day). Clinicians and patients can determine the optimal clinical dose by controlling 2 variables: (1) patch size (controlling milligrams per hour) and (2) duration of patch wear. The new paradigm is worth learning, because the patch offers several advantages over oral preparations for some patients, chiefly individualized control over effect duration (determined by when the patch is applied in the morning and removed in the afternoon/evening). Taking full advantage of this treatment option requires educating the patient and parents regarding practical elements of daily use. These elements include patch-site selection, application techniques, management of wear time to optimize the daily time course of clinical benefits, and skin hygiene. This article summarizes clinical principles that physicians may find useful in managing this new addition to the attention-deficit/hyperactivity disorder treatment armamentarium.     

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??Pediatric functional cardiovascular diseases involve a series of dysfunctions which can affect children’s physical and mental health. They include vasovagal syncope??postural tachycardia syndrome??orthostatic hypotension??orthostatic hypertension and beta-adrenoceptor hyperfunction??etc. Since the above-mentioned diseases have various therapeutic response??with the research progress of the disease mechanisms and prognosis??great progress has been made in individualized management of pediatric functional cardiovascular diseases. In the future??great attention should be paid to the individualized diagnosis and treatment of the diseases so as to improve the diagnostic and therapeutic technology.     

Characterization of methylphenidate exposures reported to a regional poison control center

OBJECTIVE: To investigate the frequency, risk population, symptoms, reason, and outcome surrounding human methylphenidate exposures reported to a regional poison control center. DESIGN: Retrospective case series. SETTING/PATIENTS: All human methylphenidate exposures reported to a regional poison control center during a 2-year period were included. MAIN OUTCOME MEASURES: Data collected included age, dose, reason for exposure, symptoms (type and severity), treatment, and outcome. Age data for all other exposures reported during the same time period were also compiled. RESULTS: The study included 289 patients. Overall, 31% developed symptoms, most commonly tachycardia, agitation, and lethargy. No patient developed severe symptoms, although a less favorable outcome was seen with intentional vs unintentional exposures. When compared with the age data for all other exposures reported during the same time period, a trimodal vs bimodal pattern was seen, with the novel peak occurring in 6- to 9-year-old children. Within this age group, therapeutic error was the most common reason for exposure. CONCLUSIONS: Methylphenidate exposure was associated with symptom development in 31% of cases. An unusually high incidence of therapeutic error was noted surrounding its use, most commonly in the 6- to 11-year-old age group, defining a unique population at risk for toxic exposure. This initial data may allow targeted poisoning prevention efforts for this age group. Arch Pediatr Adolesc Med. 2000;154:1199-1203.     

Methylphenidate double-blind trial: indication and performing

Hyperkinetic disorders or attention-deficit/hyperactivity disorders (ADHD) are among the psychiatric diagnoses most often encountered in children and adolescents. Symptoms include inattention, hyperactivity and impulsivity. Within the multi-modal treatment system, the therapy with psychostimulants (e. g. methylphenidate) proved to be an effective in patients with ADHD. A double-blind trial is indicated in cases of unclear efficacy of methylphenidate at initial application or if psychostimulants have regularly been applied for more than one year with an leave-out trial delivering unequivocal results. Further it is helpful in verifying potential undesirable side effects and improving patients' compliance.     

Albuterol overdose: a case report and differential diagnosis.

The increase in the use of selective beta 2 agonists as first-choice agents in the therapy of asthma has resulted in a concomitant increase in overdoses and other therapeutic misadventures. This case describes a 22-month-old child who ingested a large overdose of albuterol, resulting in an acute syndrome consisting of agitation, tremulousness, marked hyperglycemia of > 320 mg/dl (17.8 mmol/L), ketonuria, and hypokalemia. Such toxicity has generally been reported only in diabetics or pregnant patients. These findings and a brief review of the pharmacology and toxicology of beta 2 agonists are detailed, with special emphasis on the differential diagnosis of overdoses characterized by hyperglycemia, hypokalemia, agitation, and tremulousness. A system of ordering the relative toxicity of these (and other) drugs is proffered using the exposure-case fatality rate (ECFR) as a crude measure of clinical toxicity (while delineating its shortcomings). Applying the ECFR (using American Association of Poison Control Centers' data base) to beta 2 agonist overdoses indicates that the resulting clinical syndrome, while troublesome, generally results in a benign outcome.     

Therapeutic interventions in sexual child abuse

This article describes the steps in a therapeutic crisis intervention in cases of intrafamilial child sexual abuse. It is outlined how the form and organisation of the intervention can in itself be highly therapeutic or very harmful. Taking to children, physical examination, coordination of professionals, the disclosure with parents and a family meeting are described as part of an overall therapeutic approach in the disclosure of the abuse. The described therapeutic crisis intervention attempts to take into account paediatric-medical routine and does not refer to any specialist therapeutic techniques in order to enable any child health professional who dares to face the issue of child sexual abuse to undertake the intervention.     

Impact of maternal substance use during pregnancy on childhood outcome

The impact of maternal substance abuse is reflected in the 2002-2003 National Survey on Drug Use and Health. Among pregnant women in the 15-44 age group, 4.3%, 18% and 9.8% used illicit drugs, tobacco and alcohol, respectively. Maternal pregnancy complications following substance use include increases in sexually transmitted disorders, placental abruption and HIV-positive status. Effects on the neonate include a decrease in growth parameters and increases in central nervous system and autonomic nervous system signs and in referrals to child protective agencies. In childhood, behavioral and cognitive effects are seen after prenatal cocaine exposure; tobacco and alcohol have separate and specific effects. The ongoing use of alcohol and tobacco by the caretaker affects childhood behavior. Therefore, efforts should be made to prevent and treat behavioral problems as well as to limit the onset of drug use by adolescent children born to women who use drugs during pregnancy.     

Dilated cardiomyopathy secondary to atrial ectopic tachycardia

Ectopic atrial tachycardia is an uncommon cause of supraventricular tachycardia in children. It can resolve spontaneously or induce dilated cardiomyopathy. It is important to recognize this entity as a reversible cause of dilated cardiomyopathy, characterized by the presence of an abnormal focus located in the atrial myocardium and distinct to sinus node. Treatment strategies include the use of antiarrhythmic drugs, radiofrequency ablation, and, in patients refractory to medical treatment, surgical resection of the ectopic focus. We describe a patient with dilated cardiomyopathy due to an atrial ectopic focus and its resolution after medical treatment.     

Arrhythmia Management in the Fontan Patient

With longer duration of follow-up, as many as 50% of Fontan patients will develop atrial tachycardia, usually in association with significant hemodynamic abnormalities. Arrhythmia management in the Fontan patient is reviewed. The incidence and type of arrhythmia occurrence are examined, including macro-reentrant rhythm which involves the right atrium, reentrant rhythm localized to the pulmonary venous atrium (seen in patients with lateral tunnel procedures), and atrial fibrillation. Risk factors for development of these arrhythmias are considered, and short- and long-term therapeutic options for medical and surgical treatment are discussed. Surgical results are presented for 117 patients undergoing Fontan conversion and arrhythmia surgery (isthmus ablation (9), modified right atrial maze (38) or Cox-maze III (70)). Operative mortality is low (1/117, 0.8%). Seven late deaths occurred, and include two patients who died shortly following cardiac transplantation (2/6, 33%) after Fontan conversion and arrhythmia surgery. Overall arrhythmia recurrence is 12.8% during a mean follow-up of 56 months. Fontan conversion with arrhythmia surgery can be performed with low operative mortality, low risk of recurrent tachycardia, and marked improvement in functional status in most patients. Because the development of tachycardia is usually an electromechanical problem, attention to only the arrhythmia with medications or ablation may allow progression of hemodynamic abnormalities to either a life-threatening outcome or a point at which transplantation is the only potential option. Because cardiac transplantation in Fontan patients is associated with high early mortality, earlier consideration for surgical intervention is warranted.     

Adolescent substance abuse: diagnostic and treatment issues

For teenagers, substance use initiation peaks between 16 and 18 years of age, with the greatest use occurring over the subsequent four years, after which time there is a significant reduction in usage. Factors associated with adolescent substance abuse include rebelliousness, relative indifference to school, tolerance for social deviance, family disruption, parental tolerance of alcohol or other drug use, and early onset of drug use. One major problem for teenagers is that the diagnosis and treatment of adolescent substance abuse is based primarily on adult models of alcoholism.     

Prehospital epinephrine overdose in a child resulting in ventricular dysrhythmias and myocardial ischemia

INTRODUCTION: Epinephrine overdoses in children have been associated with supraventricular tachycardia. Myocardial ischemia subsequent to epinephrine overdose has not been reported in pediatric patients. CASE REPORT: We report a case of ventricular dysrhythmias and myocardial ischemia in a 5-year-old boy who received 10 times the recommended dose of subcutaneous epinephrine. Prehospital providers administered the epinephrine, believing it was part of a "high-dose" epinephrine protocol. DISCUSSION: There is no role for high-dose epinephrine in the treatment of allergic reactions or asthma. Careful epinephrine dosing, using mg/kg and verifying the volume, dilution, and route of administration is essential to prevent epinephrine toxicity.     

Acute thyroxine ingestion in pediatric patients

During a 1-year period, 15 cases of acute thyroxine (T4) overdose with documented serum T4 concentrations were studied. All patients were less than 5 years of age and 80% were boys. All were examined within 1 to 6 hours of ingestion and all were asymptomatic. Estimated dose ingested in 10 patients ranged from 1.5 to 8.8 mg (0.1 to 0.73 mg/kg). Three patients with initial T4 serum concentrations greater than 75 micrograms/dL manifested signs of toxicity within 12 to 48 hours (fever, tachycardia, hypertension, and/or agitation) that resolved within 24 to 60 hours. The mean elimination half-life of T4 in 7 patients with multiple serum concentrations was 2.8 +/- 0.4 days, whereas the mean elimination half-life of triiodothyronine was 6 +/- 1.7 days. It was concluded that (1) the majority of acute pediatric T4 overdoses are not severe and may be managed on an outpatient basis, (2) the absence of early clinical manifestations does not preclude delayed onset of toxicity that may be better predicted by initial T4 concentrations, and (3) the elimination half-life of T4 is shorter and the elimination half-life of tri-iodothyronine is longer than with therapeutic doses.     

Supraventricular tachycardia in the neonate and infant

Supraventricular tachycardia (SVT) is the most common sustained arrhythmia to present in the neonatal and infancy age group. Predisposing factors (congenital heart disease, drug administration, illness and fever) occur only in 15% of infants. The presentation of SVT in the neonate is frequently subtle, and may include pallor, cyanosis, restlessness, irritability, feeding difficulty, tachypnea, diaphoresis and grunting. Congestive heart failure is more common in infants under 4 months of age (35% incidence). Age-related differences in the distribution of SVT mechanisms occur in different age groups. In infants under 1 year of age, the mechanisms underlying SVT are atrial tachycardia (15%), AV nodal re-entry tachycardia (5%), and AV reciprocating tachycardia (80%). Options for acute management include: use of the diving reflex, intravenous adenosine, transesophageal pacing, and cardioversion. Intravenous administration of verapamil should be avoided. Data regarding freedom from recurrence of untreated SVT in the first year of life are limited, and may be in the range of 25-60%. Chronic therapy with digoxin, beta-blockers, flecainide, sotalol and amiodarone has proved effective in controlling recurrent episodes of SVT. Radiofrequency ablation can be employed successfully in medically refractory cases, but should be avoided in this age group (increased complication rate).     

Adolescent resilience: The potential impact of personal development in schools

Abstract The challenges and stresses faced by adolescents include entry into secondary school, the development of adolescent sexuality, family conflicts, parental mental illness, socio-cultural factors, substance use and abuse, work and career abuse, social and antisocial behaviour, and the carry-over of problems from childhood. The ways in which programmes through schools can address these issues, enhance resilience and promote adolescent mental health are discussed. The potential of personal development programmes could be utilized to this end, with targeted educational and group initiatives and evaluation of outcomes.