Potential mechanism of desipramine-related sudden death in children

Antidepressants in the treatment of adult attention-deficit hyperactivity disorder: a systematic review

INTRODUCTION

Stimulant medications are the most effective drugs in the treatment of attention-deficit hyperactivity disorder (ADHD) in children and in adults. However, some patients do not respond to this treatment and other patients suffer from adverse effects. Very often there are also comorbid disorders that warrant treatment or there is somatic comorbidity that precludes the prescription of stimulants. As a result, alternative treatments for the treatment of ADHD have been explored, such as antidepressant agents. In this systematic review the evidence base for the effect of antidepressants for ADHD in adult patients is determined.

METHODS

Electronic and hand searches were conducted in order to identify clinical trials studying antidepressants for the treatment of ADHD in adult patients. The trials were screened for methodological characteristics and treatment-effect sizes. The odds ratio was calculated for randomized controlled trials with bupropion. A descriptive review of all the randomized controlled studies and an overview of the nonrandomized studies was developed.

RESULTS

Only eight randomized controlled trials were retrieved with four different compounds. Five studies concerned bupropion and the meta-analysis indicates a beneficial effect for bupropion compared with placebo as measured with the Clinical Global Improvement Scale (odds ratio 2.42 [95% CI 1.09 to 5.36]). Several studies suffer from clinical and methodological shortcomings, such as exclusion of patients with comorbid disorders, short treatment duration, or a lack of information with respect to the randomization procedure.

CONCLUSION

Although there is a need for alternative interventions for the treatment of ADHD, such as with antidepressant agents, the evidence base is not large. Only treatment with bupropion seems to have a medium-range effect size, but this is less than that of stimulant medications.

Tricyclic antidepressant poisoning: an evidence-based consensus guideline for out-of-hospital management

A review of U.S. poison center data for 2004 showed over 12,000 exposures to tricyclic antidepressants (TCAs). A guideline that determines the conditions for emergency department referral and prehospital care could potentially optimize patient outcome, avoid unnecessary emergency department visits, reduce healthcare costs, and reduce life disruption for patients and caregivers. An evidence-based expert consensus process was used to create the guideline. Relevant articles were abstracted by a trained physician researcher. The first draft of the guideline was created by the lead author. The entire panel discussed and refined the guideline before distribution to secondary reviewers for comment. The panel then made changes based on the secondary review comments. The objective of this guideline is to assist poison center personnel in the appropriate prehospital triage and management of patients with suspected ingestions of TCAs by 1) describing the manner in which an ingestion of a TCA might be managed, 2) identifying the key decision elements in managing cases of TCA ingestion, 3) providing clear and practical recommendations that reflect the current state of knowledge, and 4) identifying needs for research. This guideline applies to ingestion of TCAs alone. Co-ingestion of additional substances could require different referral and management recommendations depending on their combined toxicities. This guideline is based on the assessment of current scientific and clinical information. The panel recognizes that specific patient care decisions may be at variance with this guideline and are the prerogative of the patient and the health professionals providing care, considering all the circumstances involved. This guideline does not substitute for clinical judgment. Recommendations are in chronological order of likely clinical use. The grade of recommendation is in parentheses. 1) Patients with suspected self-harm or who are the victims of malicious administration of a TCA should be referred to an emergency department immediately (Grade D). 2) Patients with acute TCA ingestions who are less than 6 years of age and other patients without evidence of self-harm should have further evaluation including standard history taking and determination of the presence of co-ingestants (especially other psychopharmaceutical agents) and underlying exacerbating conditions, such as convulsions or cardiac arrhythmias. Ingestion of a TCA in combination with other drugs might warrant referral to an emergency department. The ingestion of a TCA by a patient with significant underlying cardiovascular or neurological disease should cause referral to an emergency department at a lower dose than for other individuals. Because of the potential severity of TCA poisoning, transportation by EMS, with close monitoring of clinical status and vital signs en route, should be considered (Grade D). 3) Patients who are symptomatic (e.g., weak, drowsy, dizzy, tremulous, palpitations) after a TCA ingestion should be referred to an emergency department (Grade B). 4) Ingestion of either of the following amounts (whichever is lower) would warrant consideration of referral to an emergency department: an amount that exceeds the usual maximum single therapeutic dose or an amount equal to or greater than the lowest reported toxic dose. For all TCAs except desipramine, nortriptyline, trimipramine, and protriptyline, this dose is >5 mg/kg. For despiramine it is >2.5 mg/kg; for nortriptyline it is >2.5 mg/kg; for trimipramine it is >2.5 mg/kg; and for protriptyline it is >1 mg/kg. This recommendation applies to both patients who are naïve to the specific TCA and to patients currently taking cyclic antidepressants who take extra doses, in which case the extra doses should be added to the daily dose taken and then compared to the threshold dose for referral to an emergency department (Grades B/C). 5) Do not induce emesis (Grade D). 6) The risk-to-benefit ratio of prehospital activated charcoal for gastrointestinal decontamination in TCA poisoning is unknown. Prehospital activated charcoal administration, if available, should only be carried out by health professionals and only if no contraindications are present. Do not delay transportation in order to administer activated charcoal (Grades B/D). 7) For unintentional poisonings, asymptomatic patients are unlikely to develop symptoms if the interval between the ingestion and the initial call to a poison center is greater than 6 hours. These patients do not need referral to an emergency department facility (Grade C). 8) Follow-up calls to determine the outcome for a TCA ingestions ideally should be made within 4 hours of the initial call to a poison center and then at appropriate intervals thereafter based on the clinical judgment of the poison center staff (Grade D). 9) An ECG or rhythm strip, if available, should be checked during the prehospital assessment of a TCA overdose patient. A wide-complex arrhythmia with a QRS duration longer than 100 msec is an indicator that the patient should be immediately stabilized, given sodium bicarbonate if there is a protocol for its use, and transported to an emergency department (Grade B). 10) Symptomatic patients with TCA poisoning might require prehospital interventions, such as intravenous fluids, cardiovascular agents, and respiratory support, in accordance with standard ACLS guidelines (Grade D). 11) Administration of sodium bicarbonate might be beneficial for patients with severe or life-threatening TCA toxicity if there is a prehospital protocol for its use (Grades B/D). 12) For TCA-associated convulsions, benzodiazepines are recommended (Grade D). 13) Flumazenil is not recommended for patients with TCA poisoning (Grade D).

Changes in autonomic regulation with age: implications for psychopharmacologic treatments in children and adolescents

Developmental changes in the cardiovascular system could have an impact on risks associated with psychopharmacological interventions. Children may be more vulnerable to adverse cardiac events due to immaturity in autonomic control of the heart. These changes are incompletely understood and are characterized in this study. A consecutive series of 70 boys, aged 6-14 years, was recruited. Developmental variation in the autonomic nervous system was evaluated by assessing heart period variability (HPV), pulse, and blood pressure in response to orthostasis. Increased age correlated significantly with greater heart rate and diastolic blood pressure response to orthostasis. HPV at rest and in response to tilt did not significantly correlate with age. Boys with family histories of hypertension had a significantly greater blood pressure response to orthostasis. These findings suggest that developmental age-related changes in the sympathetic nervous system, as reflected by changes of pulse and blood pressure response to tilt, occur across this age range. Parasympathetic changes, as reflected by HPV, do not. In light of these findings, more research is needed on children's and adolescents' relative cardiac risk with psychotropic medications as opposed to adults'.

Cardiovascular effects of desipramine in children and adults during exercise testing

OBJECTIVE

In light of recent reports of sudden death in children being treated with desipramine (DMI), 3 of which were associated with physical exercise, the authors examined the effects of DMI on exercise in children and adults before and during DMI treatment.

METHOD

Before treatment, 22 subjects (9 children, 13 adults) participated in a graded treadmill exercise test. Outcome measures included exercise tolerance, cardiovascular, and electrocardiographic parameters at progressive intensity levels and serum norepinephrine (NE) levels before and after exercise testing. Subjects were then treated with DMI, titrated to an average DMI dosage of 3 mg/kg, and underwent repeated exercise testing.

RESULTS

DMI treatment was associated with a significant elevation of circulating NE levels in the pre-exercise assessment. Exercise tolerance was not affected by DMI, and blood pressure and heart rate effects were modest. The cardiovascular impact of DMI treatment was similar in children and adults. One 31-year-old subject exhibited a brief episode of ventricular tachycardia associated with exercise during DMI treatment.

CONCLUSIONS

DMI has only minor effects on the cardiovascular response to exercise, and these effects do not appear age-related. However, DMI may increase the risk of exercise-associated arrhythmias in rare individuals.