Selected tricyclic antidepressant ingestions involving children 6 years old or less

Systematic review on the use of activated charcoal for gastrointestinal decontamination following acute oral overdose

INTRODUCTION

The use of activated charcoal in poisoning remains both a pillar of modern toxicology and a source of debate. Following the publication of the joint position statements on the use of single-dose and multiple-dose activated charcoal by the American Academy of Clinical Toxicology and the European Association of Poison Centres and Clinical Toxicologists, the routine use of activated charcoal declined. Over subsequent years, many new pharmaceuticals became available in modified or alternative-release formulations and additional data on gastric emptying time in poisoning was published, challenging previous assumptions about absorption kinetics. The American Academy of Clinical Toxicology, the European Association of Poison Centres and Clinical Toxicologists and the Asia Pacific Association of Medical Toxicology founded the Clinical Toxicology Recommendations Collaborative to create a framework for evidence-based recommendations for the management of poisoned patients. The activated charcoal workgroup of the Clinical Toxicology Recommendations Collaborative was tasked with reviewing systematically the evidence pertaining to the use of activated charcoal in poisoning in order to update the previous recommendations.

OBJECTIVES

The main objective was: Does oral activated charcoal given to adults or children prevent toxicity or improve clinical outcome and survival of poisoned patients compared to those who do not receive charcoal?  Secondary objectives were to evaluate pharmacokinetic outcomes, the role of cathartics, and adverse events to charcoal administration. This systematic review summarizes the available evidence on the efficacy of activated charcoal.

METHODS

A medical librarian created a systematic search strategy for Medline (Ovid), subsequently translated for Embase (via Ovid), CINAHL (via EBSCO), BIOSIS Previews (via Ovid), Web of Science, Scopus, and the Cochrane Library/DARE. All databases were searched from inception to December 31, 2019. There were no language limitations.  One author screened all citations identified in the search based on predefined inclusion/exclusion criteria. Excluded citations were confirmed by an additional author and remaining articles were obtained in full text and evaluated by at least two authors for inclusion. All authors cross-referenced full-text articles to identify articles missed in the searches. Data from included articles were extracted by the authors on a standardized spreadsheet and two authors used the GRADE methodology to independently assess the quality and risk of bias of each included study.

RESULTS

From 22,950 titles originally identified, the final data set consisted of 296 human studies, 118 animal studies, and 145 in vitro studies. Also included were 71 human and two animal studies that reported adverse events. The quality was judged to have a Low or Very Low GRADE in 469 (83%) of the studies. Ninety studies were judged to be of Moderate or High GRADE. The higher GRADE studies reported on the following drugs: paracetamol (acetaminophen), phenobarbital, carbamazepine, cardiac glycosides (digoxin and oleander), ethanol, iron, salicylates, theophylline, tricyclic antidepressants, and valproate. Data on newer pharmaceuticals not reviewed in the previous American Academy of Clinical Toxicology/European Association of Poison Centres and Clinical Toxicologists statements such as quetiapine, olanzapine, citalopram, and Factor Xa inhibitors were included. No studies on the optimal dosing for either single-dose or multiple-dose activated charcoal were found. In the reviewed clinical data, the time of administration of the first dose of charcoal was beyond one hour in 97% (n = 1006 individuals), beyond two hours in 36% (n = 491 individuals), and beyond 12 h in 4% (n = 43 individuals) whereas the timing of the first dose in controlled studies was within one hour of ingestion in 48% (n = 2359 individuals) and beyond two hours in 36% (n = 484) of individuals.

CONCLUSIONS

This systematic review found heterogenous data. The higher GRADE data was focused on a few select poisonings, while studies that addressed patients with unknown and or mixed ingestions were hampered by low rates of clinically meaningful toxicity or death.  Despite these limitations, they reported a benefit of activated charcoal beyond one hour in many clinical scenarios.

Tricyclic drugs for depression in children and adolescents

BACKGROUND

There is a need to identify effective and safe treatments for depression in children and adolescents. While tricyclic drugs are effective in treating depression in adults, individual studies involving children and adolescents have been equivocal. Prescribing of tricyclic drugs for depression in children and adolescents is now uncommon, but an accurate estimate of their efficacy is helpful as a comparator for other drug treatments for depression in this age group. This is an update of a Cochrane review first published in 2000 and updated in 2002, 2006 and 2010.

OBJECTIVES

To assess the effects of tricyclic drugs compared with placebo for depression in children and adolescents and to determine whether there are differential responses to tricyclic drugs between child and adolescent patient populations.

SEARCH METHODS

We conducted a search of the Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Register (CCDANCTR) (to 12 April 2013), which includes relevant randomised controlled trials from the following bibliographic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (all years), EMBASE (1974-), MEDLINE (1950-) and PsycINFO (1967-). The bibliographies of previously published reviews and papers describing original research were cross-checked. We contacted authors of relevant abstracts in conference proceedings of the American Academy of Child and Adolescent Psychiatry, and we handsearched the Journal of the American Academy of Child and Adolescent Psychiatry (1978 to 1999).

SELECTION CRITERIA

Randomised controlled trials comparing the efficacy of orally administered tricyclic drugs with placebo in depressed people aged 6 to 18 years.

DATA COLLECTION AND ANALYSIS

One of two review authors selected the trials, assessed their quality, and extracted trial and outcome data. A second review author assessed quality and checked accuracy of extracted data. Most studies reported multiple outcome measures including depression scales and clinical global impression scales. For each study, we took the best available depression measure as the index measure of depression outcome. We established predetermined criteria to assist in the ranking of measures. Where study authors reported categorical outcomes, we calculated individual and pooled risk ratios for non-improvement in treated compared with control subjects. For continuous outcomes, we calculated pooled effect sizes as the number of standard deviations by which the change in depression scores for the treatment group exceeded those for the control group.

MAIN RESULTS

Fourteen trials (590 participants) were included. No overall difference was found for the primary outcome of response to treatment compared with placebo (risk ratio (RR) 1.07, 95% confidence interval (CI) 0.91 to 1.26; 9 trials, N = 454). There was a small reduction in depression symptoms (standardised mean difference (SMD) -0.32, 95% CI -0.59 to -0.04; 13 trials, N = 533), but the evidence was of low quality. Subgroup analyses suggested a small reduction in depression symptoms among adolescents (SMD -0.45, 95% CI -0.83 to -0.007), and negligible change among children (SMD 0.15, 95% CI -0.34 to 0.64). Treatment with a tricyclic antidepressant caused more vertigo (RR 2.76, 95% CI 1.73 to 4.43; 5 trials, N = 324), orthostatic hypotension (RR 4.86, 95% CI 1.69 to 13.97; 5 trials, N = 324), tremor (RR 5.43, 95% CI 1.64 to 17.98; 4 trials, N = 308) and dry mouth (RR 3.35, 95% CI 1.98 to 5.64; 5 trials, N = 324) than did placebo, but no differences were found for other possible adverse effects. Wide CIs and the probability of selective reporting mean that there was very low-quality evidence for adverse events.There was heterogeneity across the studies in the age of participants, treatment setting, tricyclic drug administered and outcome measures. Statistical heterogeneity was identified for reduction in depressive symptoms, but not for rates of remission or response. As such, the findings from analyses of pooled data should be interpreted with caution.We judged none of these trials to be at low risk of bias, with limited information about many aspects of risk of bias, high dropout rates, and issues regarding measurement instruments and the clinical usefulness of outcomes, which were often variously defined across trials.

AUTHORS' CONCLUSIONS

Data suggest tricyclic drugs are not useful in treating depression in children. There is marginal evidence to support the use of tricyclic drugs in the treatment of depression in adolescents.

Significant toxicity in a young female after low-dose tricyclic antidepressant ingestion

BACKGROUND

Tricyclic antidepressant (TCA) ingestions are a relatively common pediatric ingestion, with significant potential for both cardiac and neurological toxicity. Previous studies on pediatric TCA ingestions have found the threshold of toxicity to be 5 mg/kg.

CASE

We report a case of an 8-year-old girl who presented to the emergency department with depressed mental status and seizure-like movements. An extensive workup was pursued to evaluate the cause of her mental status, which only revealed a positive urine toxicology screen for TCA. Quantified serum levels of amitriptyline were 121 ng/mL (therapeutic range, 50-300 ng/mL) and nortriptyline were 79 ng/mL (therapeutic range 70-170 ng/mL), 18 hours after onset of symptoms. Subsequent history obtained after her mental status returned to normal revealed that she had ingested amitriptyline at a dose of 0.8 mg/kg.

CONCLUSIONS

Tricyclic antidepressant ingestion has a high potential for toxicity in pediatric patients. This case suggests, contrary to previous literature, that toxicity may occur even with small doses.

Clinical, electrocardiographic, and laboratory findings in children with amitriptyline intoxication

BACKGROUND

Amitriptyline is one of the major tricyclic antidepressants, and the data on amitriptyline poisoning in children are limited.

OBJECTIVES

To present our experiences with amitriptyline poisoning in children, particularly with regard to its effects on electrocardiogram (ECG) and relation with clinical status.

METHODS

Clinical, laboratory, and electrocardiographic findings in 52 children admitted with amitriptyline poisoning were reviewed. Patients were divided into 2 groups according to age, as 6 years or younger (group A) and older than 6 years (group B).

RESULTS

Mean age was 4.6 +/- 3.0 years. Thirty-one patients were male, and 41 were 6 years or younger. Ingested amitriptyline dose was known in 23 patients (range, 2.3 mg/kg-27 mg/kg). The most frequent findings were lethargy (76.9%), sinus tachycardia (57.7%), and coma (48.1%). Four patients had a history of convulsion. The most common laboratory abnormalities were hyponatremia (26.9%) and leukocytosis (25%). Elevated transaminase levels were observed in 4 patients. In ECG, 11 (22.4%) patients had QTc prolongation and in 4 (8.2%) of them, it was significant. In 4 patients (8.2%), the QRS duration was 100 ms or longer and in 15 patients, the R wave in aVR was 3 mm or longer. The frequencies of clinical, laboratory, and electrocardiographic findings were similar between the 2 age groups (P > 0.05). No clinically apparent arrhythmias were observed. The positive predictive value of a widened QRS was 100% in terms of coma. None of the patients with an R wave in aVR of less than 3 mm developed convulsion; thus, the negative predictive value of an R wave in aVR of 3 mm or longer was 100% in terms of convulsion.

CONCLUSIONS

Amitriptyline poisoning may result in severe toxicity. Frequencies of clinical, laboratory, and ECG findings were similar in the 2 age groups. Amitriptyline overdose results in some ECG changes that can possibly help to predict the results of poisoning. Absence of an R wave in aVR of 3 mm or longer predicts seizures with a high negative predictive value, and a QRS duration of 100 or longer ms predicts coma with a high positive predictive value.

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).

Pediatric Toxicology

Pediatric patients present unique concerns in the field of medical toxicology. First, there are medicines that are potentially dangerous to small children, even when they are exposed to very small amounts. Clinicians should be wary of these drugs even when young patients present with accidental ingestions of apparently insignificant amounts. Next, over-the-counter laxatives and syrup of ipecac, although not commonly considered abused substances, may be misused in both the setting of Munchausen's syndrome by proxy and in adolescents who have eating disorders. Their use should be considered in any gastrointestinal illness of uncertain origin. Finally, as the use of syrup of ipecac at home now has been discouraged by many, some have explored using activated charcoal at home as a new method of prehospital gastrointestinal decontamination. The literature examining activated charcoal and its use in this capacity is discussed.

Are one or two dangerous? Tricyclic antidepressant exposure in toddlers

Tricyclic antidepressants (TCA), increasingly prescribed for multiple indications in children and adults, are responsible for many pediatric poisonings. Though the majority of TCA exposures in this age group remain asymptomatic, several reports in the English language literature reveal significant morbidity as well as fatalities in toddlers, primarily from imipramine and desipramine. These few cases indicate that doses of 10-20 mg/kg (one to two pills) have the potential for toxicity and fatalities. More recent studies have focused on the relative safety of small exposures suggesting that with doses less than 5 mg/kg the patient may be safely observed at home. Though further studies are necessary to determine the exact dosing that places the child at risk, the authors recommend a 6-h Emergency Department observation period for children who ingest more than 5 mg/kg of most TCAs, as clinical toxicity becomes evident within this time frame.

Comparative tolerability of drug treatment for nocturnal enuresis in children

Primary nocturnal enuresis is one of the most frequent complaints in paediatric and urologic practice. Physicians face the dilemma of whether or not to treat primary nocturnal enuresis since the trend towards spontaneous remission is countered by social disadvantages and reduced self esteem of the children affected and their families. We reviewed randomised, controlled trials investigating efficacy and adverse effects of current medical treatment for primary nocturnal enuresis. Only desmopressin and imipramine displayed significant effects in reducing wet nights: when compared with baseline bedwetting or placebo controls, 30-70% of the studied children achieved therapeutic success. For drugs such as indometacin or oxybutynin, convincing studies displaying a significant positive effect are still needed. However, considering the adverse effects profiles of desmopressin and imipramine it can be seen that imipramine is associated with about twice as many unwanted reactions. More importantly, a serious adverse effect of imipramine is sudden cardiac arrest. In general, adverse effects with desmopressin are rare and mild, but there have been a number of case reports of hyponatraemic hypervolaemia associated with coma and seizures. Of these, many cases were attributed to excess water intake before taking the drug and all children recovered fully. In summary, if medical treatment is considered, preference should be given to desmopressin.

Use of dosage as a triage guideline for unintentional cyclic antidepressant (UCA) ingestions in children

Triage guidelines for unintentional cyclic antidepressant (UCA) ingestions vary widely, with limited supportive evidence. All records of UCA ingestion reported to 4 certified regional poison centers were evaluated for the years 1998 through 2000. Inclusion criteria included age </=6 years patients with a known outcome and known ingested dose by history. Exclusion criterion was polydrug ingestion. Two hundred forty-six cases were evaluated. The mean age was 2.4 years (standard deviation, +/-1.2 y). One hundred thirty-six patients (55%) were managed in a hospital. One hundred ten patients were managed at home with observation and telephone follow up. Symptoms reported were drowsiness (n = 59), tachycardia (n = 4), agitation (n = 2), coma (n = 2), respiratory depression (n = 1), and ataxia (n = 1). Medical outcome was reported as no effect (n = 185; 75%), minor effect (n = 57; 23%), moderate effect (n = 2; 1%); and major effect (n = 2; 1%). Mean dosage of patients with and without symptoms was 6.3 mg/kg (+/- 9.3) and 2.9 mg/kg (+/- 3.1), respectively. Forty-three of 57 patients (75%) with minor symptoms reported a dosage of <5 mg/kg. All patients with a moderate or major outcome (n = 4) reported a dosage of >5 mg/kg. The majority of UCA ingestions produced limited or no symptomatology. In this series, all children with ingestions of <5 mg/kg developed no or minor effects. Home monitoring might be appropriate in such cases.