A retrospective analysis of antidepressant poisonings in the emergency department: 11-year experience

Antidepressant Poisoning Trends in Pediatric Intensive Care: A Comparative Study of New- and Old-Generation Antidepressants

PURPOSE/BACKGROUND

This study aimed to compare the frequency, clinical findings, treatment practices, and outcomes of toxicity to old-generation (OG) and new-generation (NG) antidepressants in our pediatric intensive care unit (PICU) by year-to-year.

METHODS/PROCEDURES

The study included patients hospitalized for antidepressant poisoning during the 11-year period of January 2010 through December 2020. Antidepressants were classified as OG and NG. The groups were compared in terms of patient demographic characteristics, type of poisoning (accidental/suicidal), clinical findings, supportive and extracorporeal treatments received, and outcomes.

FINDINGS/RESULTS

The study included 58 patients (NG, n = 30; OG, n = 28). The median age of the patients was 178 months (range, 13.6-215 months) and 47 patients (81%) were female. Patients admitted for only antidepressant poisoning constituted 13.3% of all poisoning cases (58/436). Of these, 22 cases (37.9%) were accidental and 36 (62.3%) were suicidal. The most common cause of poisoning was amitriptyline (24/28) in the OG group and sertraline (13/30) in the NG group. Neurological symptoms were significantly more common in the OG group (76.2% vs 23.8%), while gastrointestinal involvement was more common in the NG group (82% vs 18%; P = 0.001 and P = 0.026, respectively). Old-generation antidepressant poisoning was associated with more frequent intubation (4 vs 0 patients, P = 0.048) and longer length of PICU stay (median, 1 day [range, 1-8] vs 1 day [range, 1-4], P = 0.019). Rates of therapeutic plasma exchange and intravenous lipid emulsion therapy did not differ ( P = 0.483 and P = 0.229, respectively).

IMPLICATIONS/CONCLUSIONS

In poisoned patients, proper evaluation and management of patients requiring PICU admission are vital for favorable patient outcomes.

Prognostic factors in acute poisoning with central nervous system xenobiotics: development of a nomogram predicting risk of intensive care unit admission

Background

Acute intoxication with central nervous system (CNS) xenobiotics is an increasing global problem. Predicting the prognosis of acute toxic exposure among patients can significantly alter the morbidity and mortality. The present study outlined the early risk predictors among patients diagnosed with acute exposure to CNS xenobiotics and endorsed bedside nomograms for identifying patients requiring intensive care unit (ICU) admission and those at risk of poor prognosis or death.

Methods

This study is a 6-year retrospective cohort study conducted among patients presented with acute exposure to CNS xenobiotics.

Results

A total of 143 patients' records were included, where (36.4%) were admitted to the ICU, and a significant proportion of which was due to exposure to alcohols, sedative hypnotics, psychotropic, and antidepressants (P = 0.021). ICU admission was associated with significantly lower blood pressure, pH, and HCO₃ levels and higher random blood glucose (RBG), serum urea, and creatinine levels (P < 0.05). The study findings indicate that the decision of ICU admission could be determined using a nomogram combining the initial HCO₃ level, blood pH, modified PSS, and GCS. HCO₃ level < 17.1 mEq/L, pH < 7.2, moderate-to-severe PSS, and GCS < 11 significantly predicted ICU admission. Moreover, high PSS and low HCO₃ levels significantly predicted poor prognosis and mortality. Hyperglycemia was another significant predictor of mortality. Combining initial GCS, RBG level, and HCO₃ is substantially helpful in predicting the need for ICU admission in acute alcohol intoxication.

Conclusion

The proposed nomograms yielded significant straightforward and reliable prognostic outcomes predictors in acute exposure to CNS xenobiotics.

Relationship between tracheal intubation and the drugs used by patients with drug overdose due to self-harm

Background

Tracheal intubation may be performed in patients with drug overdose due to self-harm; however, the details of the causative drug are unknown. The purpose of this study was to clarify the relationship between drugs or its blood levels of patients with drug overdose and the need for tracheal intubation based on the actual measurement results.

Methods

From October 2018 to March 2020, 132 patients with drug overdose due to self-harm who were transported to the emergency department (ED) were studied. Patient drugs were measured using gas chromatography–mass spectrometry (GC-MS) and were analyzed on the basis of the GC/MS Forensic Toxicological Database. Logistic analysis was performed by combining patient information and GC-MS information.

Results

The Glasgow Coma Scale (GCS) and Japan Coma Scale (JCS) efficiently predicted tracheal intubation in patients with drug overdose during transport triage; GCS (cut-off value: 12, area under the curve (AUC): 0.81, 95% confidence interval (CI): 0.71–0.88, sensitivity: 0.85, specificity: 0.71, P < 0.05) and JCS (cut-off value: 3, AUC: 0.74, 95% CI: 0.60–0.84, sensitivity: 0.60, specificity: 0.84, P < 0.05). The drugs detected in all patients with drug overdose in order were benzodiazepine receptor agonists (BZs; 43.9%), anticonvulsants (38.6%), antipsychotics (25.0%), and antidepressants (9.8%). In univariate logistic analysis, antipsychotics (odds ratio (OR) 2.46, 95% CI 1.19–5.20, P < 0.05), anticonvulsants (OR 2.71, 95% CI 1.26–5.98, P < 0.05), and anticonvulsants above alert blood levels (OR 27.8, 95% CI 2.92–264.1, P < 0.05) were significantly associated with tracheal intubation in patients with drug overdose, but not BZs and antidepressants. Also, in multivariate logistic analysis, antipsychotics (OR 2.27, 95% CI 1.07–4.83, P < 0.05), anticonvulsants (OR 2.50, 95% CI 1.14–5.64, P < 0.05) and in multivariate logistic analysis of blood levels, anticonvulsants above the alert blood levels (OR 24.9, 95% CI 2.56–241.6, P < 0.05) were significantly associated with tracheal intubation in patients with drug overdose respectively.

Conclusions

Logistic analysis revealed that the use of anticonvulsants and antipsychotics were significantly associated with an increased OR in the tracheal intubation of patients with drug overdose due to self-harm.

Endotracheal Intubation in the Pharmaceutical-Poisoned Patient: a Narrative Review of the Literature

INTRODUCTION

Endotracheal intubation (ETI) is an essential component of the supportive care provided to the critically ill patient with pharmaceutical poisoning; however, specific nuances surrounding intubation including techniques and complications in the context of pharmaceutical poisoning have not been well elucidated.

DISCUSSION

A search of the available literature on ETI in pharmaceutical-poisoned patients was undertaken using Medline, ERIC, Cochrane database, and PsycINFO using the following MeSH and keyword terms: ("toxicology" OR "poisons" OR "drug overdose" OR "poisoning") AND ("intubation, intratracheal" OR "intubation, endotracheal" OR "airway management" OR "respiration, artificial"). A hand-search was also performed when the literature in the above search required additional conceptual clarification, including using the "Similar Articles" feature of PubMed, along with reviewing articles' reference lists that discussed intubation in the context of a poisoning scenario. Articles with any discussion around the ETI process in the context of a pharmaceutical poisoning were then included. Intubation may be performed in patients poisoned with pharmaceuticals in the context of both single and multiple organ dysfunction including central and peripheral nervous system, pulmonary, or cardiovascular toxicity with hemodynamic instability, or localized effects resulting in mechanical airway obstruction. Certain classes of poisonings may require modifications to the standard rapid sequence induction airway management algorithm.

CONCLUSIONS

ETI is a key component of the supportive care provided to the patient poisoned by a pharmaceutical agent. Clinicians should be aware of the spectrum of toxicities that can necessitate intubation, as well as airway management nuances that are specific to various poisoning presentations.

Review article: Emergency endotracheal intubation in non-traumatic brain pathologies: A systematic review and meta-analysis

Endotracheal intubation is an advanced airway procedure performed in the ED and the out-of-hospital setting for acquired brain injuries that include non-traumatic brain pathologies such as stroke, encephalopathies, seizures and toxidromes. Controlled trial evidence supports intubation in traumatic brain injuries, but it is not clear that this evidence can be applied to non-traumatic brain pathologies. We sought to analyse the impact of emergency intubation on survival in non-traumatic brain pathologies and also to quantify the prevalence of intubation in these pathologies. We conducted a systematic literature search of Medline, Embase and the Cochrane Library. Eligibility, data extraction and assessment of risk of bias were assessed independently by two reviewers. A bias-adjusted meta-analysis using a quality-effects model pooled prevalence of intubation in non-traumatic brain pathologies. Forty-six studies were included in this systematic review. No studies were suitable for meta-analysis the primary outcome of survival. Thirty-nine studies reported the prevalence of intubation in non-traumatic brain pathologies and a meta-analysis showed that emergency intubation was used in 12% (95% CI 0-33) of pathologies. Endotracheal intubation was used commonly in haemorrhagic stroke 79% (95% CI 47-100) and to a lesser extent for seizures 18% (95% CI 10-27) and toxidromes 25% (95% CI 6-48). This systematic review shows that there is no high-quality clinical evidence to support or refute emergency intubation in non-traumatic brain pathologies. Our analysis shows that intubation is commonly used in non-traumatic brain pathologies, and the need for rigorous evidence is apparent.

Opipramol Overdose Presented with Wide-Complex Tachycardia to the Emergency Department

Opipramol is an antidepressant and anxiolytic drug similar in structure to tricyclic antidepressants (TCAs) but it is primarily used for the treatment of generalized anxiety disorders. Unlike many TCAs, opipramol has no reuptake-inhibiting properties. Opipramol acts as a high affinity sigma receptor agonist. Opipramol acts as a low to moderate affinity antagonist for the dopamine-2 (D2), 5-hydroxtryptamine (5-HT2), histamine 1 (H1), histamine 2 (H2), and muscarinic acetylcholine receptors accounting for its antihistamine effects, and muscarinic anticholinergic properties. Here, we report a rare case of opipramol overdose case involving a 18-year-old woman, presenting to our emergency department (ED) with loss of consciousness and wide-complex tachycardia. A firm diagnosis of opipramol overdose was made on the basis of clinical, laboratory and electrocardiogram findings.

Poisonings Associated with Intubation: US National Poison Data System Exposures 2000-2013

Patients may be intubated after exposure to a variety of substances because of respiratory failure, CNS sedation, pulmonary pathology, or cardiovascular instability. However, there is little data describing the types of substances that are associated with endotracheal intubation or the rates of intubation after these exposures. Evaluation of this association may inform future research on intubation after exposures to specific substances and guide poison prevention education. Our objective was to determine which exposures were commonly associated with intubation using the data from National Poison Data System (NPDS). The NPDS tracks data from potential exposures to substances reported to all American Association of Poison Control Centers. We performed a retrospective analysis of NPDS data from January 1st, 2000 to December 31st, 2013 to identify human exposures to substances that were associated with endotracheal intubation. Descriptive statistics were used to analyze the data. There were 93,474 single substance exposures and 228,507 multiple substance exposures that were associated with intubation. The most common exposures to substances that were associated with intubation were atypical antipsychotics (7.4 %) for single exposures and benzodiazepines (27.4 %) for multiple exposures. Within each age group, the most common known exposures to substances were for patients under 6 years, clonidine for single and multiple exposures; for patients aged 6-12 years, clonidine for single exposures and atypical antipsychotics for multiple exposures; for patients aged 13-19 years, atypical antipsychotics for single and multiple exposures; and for patients over 19 years, atypical antipsychotics for single exposures and benzodiazepines for multiple exposures. From 2000-2013, the exposures to substances most commonly associated with intubation varied by single versus multiple exposures and by age. This study helps clarify the exposures to substances that are associated with intubation reported to poison centers in the USA.

Endotracheal Intubation for Toxicologic Exposures: A Retrospective Review of Toxicology Investigators Consortium (ToxIC) Cases

BACKGROUND

Endotracheal intubation remains a cornerstone of early resuscitation of the poisoned patient, but little is known about which substances are associated with intubation.

OBJECTIVES

Our objective was to describe patient exposures to substances reported to the American College of Medical Toxicology (ACMT) Toxicology Investigators Consortium (ToxIC) that were managed with intubation between 2010 and 2014.

METHODS

We performed a retrospective review of cases managed with endotracheal intubation in the ACMT ToxIC Registry from January 1, 2010 through December 31, 2014. Descriptive statistics were used to describe patient exposures.

RESULTS

A total of 2724 exposures to substances were managed with endotracheal intubation. Intubated patients were 52% male and 82% adults. For all ages taken together, the most common known single-substance exposures managed with intubation were sedative hypnotics (9.8%), antidepressants (8.7%), and opioids (8.0%). The most common single ingestions associated with intubation in various age groups were: opioids (<2 years old), alpha-2 agonists (2-6 years old), antidepressants (7-18 years old), sedative-hypnotics (19-65 years old), and cardiac medications (>65 years old). Multiple substances were involved in 29.0% of exposures. Decontamination and elimination processes were used in 12.8% of patients.

CONCLUSIONS

The most common substances involved in single- and multiple-substance exposures managed with intubation varied by age group. Most patients were managed with supportive care. Knowledge of substances commonly involved in exposures managed with intubation may inform triage and resource planning in the emergency department resuscitation of critically ill poisoned patients.

Comparison of different scores as predictors of mechanical ventilation in drug overdose patients

The decision of intubation and mechanical ventilation in poisoned patients with impaired consciousness can be a difficult task. The present study aimed to evaluate the power of Glasgow Coma Scale (GCS), acute physiology and chronic health evaluation (APACHE II), rapid acute physiology score (RAPS) and rapid emergency medicine score (REMS) at admission in predicting the need of intubation and mechanical ventilation in drug overdose patients with disturbed consciousness level (DCL). This prospective observational study was conducted on 104 poisoned patients who were admitted to Tanta Toxicological Unit with a DCL. Four scoring systems (GCS, APACHE II, RAPS and REMS) were recorded for all patients on admission. Discrimination was evaluated using receiver operating characteristics curve and calculating the area under the curve (AUC). Twenty-four cases required mechanical ventilation. The mechanically ventilated patients had significantly lower value of GCS and higher values of APACHE II, REMS and RAPS than other group ( p < 0.001). Although the APACHE II score has the best AUC value (0.796) in predicting mechanical ventilation, there was no statistically significant difference between the four scores. GCS > 8 had 100% negative predictive value, while REMS > 8 had 100% positive predictive value.

Antidepressant or Antipsychotic Overdose in the Intensive Care Unit - Identification of Patients at Risk

It is often advised that patients who have ingested an overdose of antidepressants (AD) or antipsychotics (AP) are monitored with continuous ECG for minimum of 12-24 hr. These patients are often observed in an ICU. Our aim was to identify the number of patients with AD and/or AP overdose without adverse signs at hospital admission that turned out to need intensive care treatment. The effect of the antidepressants overdose risk assessment (ADORA) system was evaluated in patients with antidepressant as well as antipsychotic overdose. Our hypothesis was that patients with low ADORA do not need intensive care treatment. This retrospective study was conducted in adult patients admitted to the ICU at Odense University Hospital after an overdose with AP and/or AD between 1 January 2009 and 1 September 2014. Patients with predefined adverse signs in the emergency department were excluded due to obvious need of intensive care. Of the 157 patients included, 12 patients (8%) developed events during the ICU stay. Only 3 patients received intubation, vasoactive drugs and/or dialysis. None developed ventricular dysrhythmias. There were no fatalities. All the patients with low-risk assessment by ADORA within the first 6 hr did not develop events within the first 24 hr after hospital admission. The vast majority of patients with AD and/or AP overdose and no adverse signs at admission did not require intensive care treatment. Low-risk ADORA identified patients with antidepressant as well as antipsychotic overdose who would not require initial intensive care treatment. This is the first time the ADORA system has been evaluated in patients with antidepressant as well as antipsychotic overdose.

Effects of 2-Hydroxypropyl-Beta-Cyclodextrin on Cardiovascular Signs of Amitriptyline Poisoning in a Rat Model

The aim of this study was to investigate the efficacy of 2-hydroxypropyl-beta-cyclodextrin (HPBCD) as an antidotal treatment for the in vivo cardiovascular effects of amitriptyline poisoning. Experiments were carried out on 33 Wistar rats. To evaluate cardiovascular effects of HPBCD, rats were infused with dextrose or HPBCD. In the poisoning model, amitriptyline (0.94 mg/kg/min) was infused until the mean arterial blood pressure (MAP) dropped to 50 % of the baseline. Following amitriptyline infusion, dextrose, low-dose HPBCD (4.19 mg/kg/min), or high-dose HPBCD (16.76 mg/kg/min) was infused, and MAP, heart rate (HR), and electrocardiogram were recorded for 60 min. Hearts were examined for tissue damage and apoptosis. HPBCD infusion alone did not yield significant difference for MAP, HR, QRS duration, QT interval, and cardiac tissue damage when compared to dextrose (p > 0.05). In the poisoning model, MAP and HR decreased, while QRS duration and QT interval prolonged significantly following amitriptyline infusion (p < 0.0167). Dextrose, low-dose HPBCD, and high-dose HPBCD infusion similarly corrected MAP, HR, QRS duration, and QT interval values at the end-experiment time point (p > 0.05). Histological scores for tissue damage and apoptosis showed no significant difference between the groups (p > 0.05). Based on our results, HPBCD did not show cardiovascular toxicity, while it was not more effective than dextrose for the treatment of amitriptyline poisoning. Further antidotal studies of cyclodextrins with higher doses and/or binding affinities are needed for poisonings.

Glasgow Coma Scale for outcome prediction after cardiac surgery: is it applicable?

OBJECTIVES

The Glasgow Coma Scale (GCS) is used commonly for assessing patients' neurologic condition and outcome in intensive care units (ICUs); however, its reliability in cardiac surgical patients has been questioned. It has been claimed that active sedation is the cause of its unsuitability for these patients. This study aimed to compare the accuracy of GCS in cardiac surgical patients with and without active sedation to find out if the inapplicability of GCS in surgical patients is related to active sedation.

DESIGN

This was an observational cohort study.

SETTING

The study was conducted in a cardiac surgical intensive care unit between January 1, 2007 and December 31, 2009.

PARTICIPANTS

All consecutive adult cardiac surgical patients were included in this study.

INTERVENTIONS

All types of cardiac surgical procedures performed during the study period were included without any exceptions. The study population was divided into 2 groups: sedated and non-sedated.

MEASUREMENTS AND MAIN RESULTS

GCS was calculated daily for the first 7 postoperative days. The authors developed a new 4-point neurologic descriptor (ND): (1) neurologically free, (2) ICU psychosis, (3) actively sedated, and (4) documented focal neurologic deficits. The accuracy of both scales (GCS and ND) at predicting ICU mortality was compared by replacing the GCS in the Sequential Organ Failure Assessment (SOFA) score with the new ND, producing a modified SOFA. GCS was not an accurate outcome predictor in non-sedated or sedated patients. The ND was superior to GCS. Correspondingly, the modified SOFA showed a significantly higher accuracy of ICU-mortality prediction than the original SOFA.

CONCLUSIONS

Regardless of active sedation, GCS is not accurate at outcome prediction for cardiac surgical patients. The suggested ND is a simple and more accurate risk stratification variable in cardiac surgical ICUs.

Amitriptyline overdose in emergency department of university hospital: evaluation of 250 patients

OBJECTIVE

The purpose of this study was to evaluate the patients with acute amitriptyline poisoning and investigate predictive factors for the development of life-threatening complications.

METHODS

Demographics, clinical, laboratory, and electrocardiographic (ECG) findings of 250 patients were evaluated retrospectively. Predictive parameters for the development of serious complications were studied.

RESULTS

Median age of patients was 14.6 years, of which, 70% of patients were female and 66% were in pediatric age group. The most common pathological clinical finding and laboratory abnormality were alteration of consciousness and hyponatremia. The rate of convulsive seizure, arrhythmia, and respiratory depression were 17 (6.8%), 16 (6.4%), and 11 (4.4%), respectively. These complications were more seen in pediatric patients than adults (15.8% and 1.2%). The incidence of hyponatremia was more in pediatric patients and severe poisoning groups (38.8 and 53.4%, respectively). The levels of amitriptyline and nortriptyline were significantly higher in the group with complications than the group without complications (p < 0.05). All adult patients were discharged with good prognosis. In pediatric age group, one patient was discharged with severe neurological sequelae and one patient died. QRS duration >100 ms, long corrected QT duration interval, and low Glasgow Coma Score (GCS) at admission were identified as independent risk factors for the development of life-threatening complications (odds ratio: 69.4, 1.9, and 1383, respectively; p < 0.05).

CONCLUSION

Amitriptyline poisoning may be associated with life-threatening complications, especially in pediatric age group and in patients with hyponatremia. Low GCS, presence of hyponatremia, high serum drug levels, and pathological ECG findings on admission may be helpful in predicting the development of complications and poor prognosis.

Applicability of different scoring systems in outcome prediction of patients with mixed drug poisoning-induced coma

Background:

Mixed drugs poisoning (MDP) is common in the emergency departments. Because of the limited number of intensive care unit beds, recognition of risk factors to divide the patients into different survival groups is necessary. Poisoning due to ingestion of different medications may have additive or antagonistic effects on different parameters included in the scoring systems; therefore, the aim of the study was to compare applicability of the different scoring systems in outcomes prediction of patients admitted with MDP-induced coma.

Methods:

This prospective, observational study included 93 patients with MDP-induced coma. Clinical and laboratory data conforming to the Acute Physiology and Chronic Health Evaluation (APACHE II), Modified APACHE II Score (MAS), Mainz Emergency Evaluation Scores (MEES) and Glasgow Coma Scale (GCS) were recorded for all patients on admission (time₀) and 24 h later (time₂₄). The outcome was recorded in two categories: Survived with or without complication and non-survived. Discrimination was evaluated using receiver operating characteristic (ROC) curves and area under the ROC curve (AUC).

Results:

The mortality rate was 9.7%. Mean of each scoring system was statistically significant between time₀ and time₂₄ in the survivors. However, it was not significant in non-survivors. Discrimination was excellent for GCS₂₄ (0.90±0.05), APACHE II₂₄ (0.89±0.01), MAS₂₄ (0.86±0.10), and APACHE II₀ (0.83±0.11) AUC.

Conclusion:

The GCS₂₄, APACHE II₂₄, MAS₂₄, and APACHE II₀ scoring systems seem to predict the outcome in comatose patients due to MDP more accurately. GCS and MAS may have superiority over the others in being easy to perform and not requiring laboratory data.

The role of adenosine receptors on amitriptyline-induced electrophysiological changes on rat atrium

We investigated the role of adenosine receptors in amitriptyline-induced cardiac action potential (AP) changes in isolated rat atria. In the first group, APs were recorded after cumulative addition of amitriptyline (1 μM, 10 μM and 50 μM). In other groups, each atrium was incubated with selective adenosine A1 antagonist (8-cyclopentyl-1,3-dipropylxanthine (DPCPX), 10−4 M) or selective adenosine A2a receptor antagonist (8-(3-chlorostyryl) caffeine, 10−5 M) before amitriptyline administration. Resting membrane potential, AP amplitude (APA), AP duration at 50% and 80% of repolarization (APD50 and APD80, respectively), and the maximum rise and decay slopes of AP were recorded. Amitriptyline (50 μM) prolonged the APD50 and APD80 ( p < 0.001) and the maximum rise slope of AP was reduced by amitriptyline ( p < 0.0001). Amitriptyline reduced maximum decay slope of AP only at 50 μM ( p < 0.01). DPCPX significantly decreased the 50-μM amitriptyline-induced APD50 and APD80 prolongation ( p < 0.001). DPCPX significantly prevented the effects of amitriptyline (1 μM and 50 μM) on maximum rise slope of AP ( p < 0.05). DPCPX significantly prevented the amitriptyline-induced (50 μM) reduction in maximum decay slope of AP ( p < 0.001). The selective adenosine A1 receptor antagonist prevented the electrophysiological effects of amitriptyline on atrial AP. A1 receptor stimulation may be responsible for the cardiovascular toxic effects produced by amitriptyline.

Adenosine-mediated cardiovascular toxicity in amitriptyline-poisoned rats

We investigated the contribution of endogenous adenosine to amitriptyline-induced cardiovascular toxicity in rats. A control group of rats was pretreated with intraperitoneal (i.p.) 5% dextrose and received intravenous 0.94 mg/kg/min of amitriptyline for 60 minutes. The second and third groups of rats pretreated with i.p. 10 mg/kg of erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), an adenosine deaminase inhibitor, and i.p. 1 mg/kg of S-(4-nitrobenzyl)-6-thioinosine (NBTI), a facilitated adenosine transport inhibitor, received 5% dextrose and amitriptyline infusion, respectively. Outcome parameters were mean arterial pressure (MAP), heart rate (HR), QT and QRS durations, and plasma adenosine concentrations. Plasma adenosine concentrations were increased in all groups. In the control group, amitriptyline decreased MAP and HR and prolonged QT and QRS durations after 10 minutes of infusion. In EHNA/NBTI-pretreated rats, amitriptyline prolonged QRS duration at 10 and 20 minutes. In EHNA/NBTI pretreated rats, amitriptyline-induced MAP, HR reductions, and QRS prolongations were more significant than that of dextrose-infusion-induced changes. Our results indicate that amitriptyline augmented the cardiovascular effects of endogen adenosine by increasing plasma levels of adenosine in rats.

Glasgow coma scale and its components on admission: are they valuable prognostic tools in acute mixed drug poisoning?

Introduction. The verbal, eye, and motor components of Glasgow coma scale (GCS) may be influenced by poisoned patients' behavior in an attempted suicide. So, the values of admission GCS and its components for outcomes prediction in mixed drugs poisoning were investigated. Materials and Methods. A followup study data was performed on patients with mixed drugs poisoning. Outcomes were recorded as without complications and with complications. Discrimination was evaluated by calculating the area under the receiver operating characteristic curves (AUC). Results. There was a significant difference between the mean value of each component of GCS as well as the total GCS between patients with and without complication. Discrimination was best for GCS (AUC: 0.933 ± 0.020) and verbal (0.932 ± 0.021), followed by motor (0.911 ± 0.025), then eye (0.89 ± 0.028). Conclusions. Admission GCS and its components seem to be valuable in outcome prediction of patients with mixed drug poisoning.

Tricyclic antidepressants intoxication in Tehran, Iran: epidemiology and associated factors

BACKGROUND

Tricyclic antidepressant (TCA) intoxication contributes a large number of drug toxicities with serious complications. There are a few studies about factors associated with TCA intoxication. This study therefore aimed to identify determinants of this type of intoxication.

METHODS

A cross-sectional study was carried out at Loghman-Hakim Poison Hospital during a 6-month period. All poisoned patients aged >12 years presented to this hospital during the mentioned period were evaluated. Then, TCA-poisoned patients were compared with other drug intoxications as the control group to determine factors associated with TCA intoxications.

RESULTS

There were 9809 admissions, of which 1583 (16.1%) patients including 601 (38%) males were intoxicated with TCAs. Mean age of the subjects was 26.5 + 10 years. Most of the TCA intoxications (74.4%) were intentional (p = 0.01). Amitriptyline was the most frequent agent followed by Nortriptyline. There was no significant difference between TCA and non-TCA intoxications regarding the mortality (1.3% in TCA vs. 1.1% in others, p = 0.45). Logistic regression analysis revealed that sex, addiction status, and history of psychological problems have association with TCA intoxication.

CONCLUSIONS

The results of this study are helpful in identifying individuals who are prone to TCA intoxication and may be useful in implementation of preventive strategies.

Current and Emerging Detoxification Therapies for Critical Care

Toxicity resulting from prescription drugs such as tricyclic antidepressants and cardioactive steroids, as well as drugs of abuse and exposure to environmental chemicals, represents a major need for detoxification treatments. Particles and colloids, antibody fragments (Fab), and indirect treatment methods such as macroemulsions, are currently being developed or employed as detoxification therapies. Colloids, particles, and protein fragments typically mitigate toxicity by binding to the toxin and reducing its concentration in vital organs. Indirect methods such as macroemulsions and sodium bicarbonate act directly on the affected organs, rather than the toxin. In this review, key design parameters (i.e. binding affinity, biocompatibility, pharmacokinetics) are discussed for each type of detoxification treatment. In addition, some of the latest research in each area is reviewed.

Self-poisonings with tricyclic antidepressants and selective serotonin reuptake inhibitors in Tehran, Iran

In a prospective hospital-based cohort study, we addressed the question of severity and outcome of antidepressant poisonings in patients who attended the Loghman-Hakim Hospital Poison Center, the only national center in Tehran dedicated for detoxification. The aim of the study was to find out if tricyclic antidepressant (TCA) intoxications require more therapeutic efforts than selective serotonin reuptake inhibitor (SSRI) intoxications. The study was applied over a 7-week period (28 March-20 May 2006). From 3578 intoxications, 334 patients with antidepressant or lithium self-poisoning were identified (9.3% of all poisoning cases; 233 females, 101 males; median age 24 years, min 13, max 70). Compared to SSRI single-substance intoxications (n=17), TCA single-substance intoxications (n=73) were associated with: (1) a significantly lower level of consciousness (P=0.005); (2) a significantly higher admission frequency (80.8 vs. 35.3%; P<0.001); and (3) a higher intubation frequency (13.7 vs. 0%; P=ns). SSRI multiple-substance intoxications were associated with a significantly lower level of consciousness than SSRI single-substance intoxications (P=0.042), while there was no significant difference between TCA multiple- and single-substance intoxications. This study suggests that an overdose with SSRIs results in a more favourable clinical outcome than an overdose with TCAs.

Risk assessment of severe tricyclic antidepressant overdose

Prognostic factors for severe complications in tricyclic antidepressant (TCA) overdose remain unclear. We therefore evaluated the value of clinical characteristics and electrocardiograph (ECG) parameters to predict serious events (seizures, arrhythmia, death) in severe TCA overdose of 100 patients using logistic regression models for risk assessment. The overall fatality rate was 6%, arrhythmia occurred in 21% and 31% of the patients developed seizures. Using an univariable logistic regression model, the maximal QRS interval (OR 1.22; 95% CI 1.06-1.41; p = .005), the time lag between ingestion and occurrence of first symptoms of overdose (OR 1.13; 95% CI 0.99-1.29; p = .072) and the age (OR 0.73; 95% CI 0.55-0.98; p = .038) were determined as the solely predictive parameters. In the multivariable logistic regression model, the QRS interval could not be established as independent predictor, however, the terminal 40-ms frontal plane QRS vector (T40) reached statistical significance regarding prediction of serious events (odds ration [OR] 1.70; 95% confidence interval [CI] 1.02-2.84; p = .041), along with age and time lag between ingestion and onset of symptoms of overdose with a sensitivity and specificity of 71% and 70%, respectively. Evaluation of both clinical characteristics and ECG-parameters in the early stage of TCA overdose may help to identify those patients who urgently need further aggressive medical observation and management.

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.

Effect of glucagon on amitriptyline-induced cardiovascular toxicity in rats

The aim of this study was to investigate the effect of glucagon on cardiovascular parameters in anesthetized rat model of tricyclic antidepressant overdose. Toxicity was induced by infusion of amitriptyline 0.94 mg/kg/min until a 40–45% of reduction in mean arterial pressure was observed. Amitriptyline infusion rats were then randomized into three groups. Control group of rats (group 1) received a bolus of 5% dextrose followed by the continuous infusion of dextrose, whereas treatment groups received 1 mg/kg (group 2) or 2 mg/kg (group 3) bolus doses of glucagon followed by continuous infusion (0.1 mg/kg/min) of glucagons for 60 min. Mean arterial pressure, heart rate, and electrocardiogram were recorded. Amitriptyline caused a significant decrease in mean arterial pressure and a prolongation in QRS, yet it did not change the heart rate. High-bolus dose of glucagon (2 mg/kg) followed by glucagon infusion significantly increased mean arterial pressure at 40, 50, and 60 min ( P < 0.05) and shortened the prolonged QRS at 50 and 60 min ( P < 0.05) when compared with control group. There was also a significant increase in heart rate. In conclusion, bolus doses followed by a continuous infusion of glucagon were found to be effective in reversing the hypotension and QRS prolongation in the rat model of amitriptyline toxicity. Further studies are needed to reveal the exact mechanism of the proposed effect.

Uptake of amitriptyline and nortriptyline with liposomes, proteins, and serum: implications for drug detoxification

Liposomes composed of DOPG and DMPC were studied for their ability to sequester amitriptyline and nortriptyline under physiological conditions. The liposomes reduced the free drug concentration in protein mixtures and in human serum, but the drug uptake efficiency of liposomes was reduced in the presence of plasma proteins, perhaps due to adsorption of proteins on the liposomes. The reduction was significantly more for the pure DOPG liposomes. The 50:50 DMPC:DOPG liposomes (0.72 mg lipid/mL) reduced the free amitriptyline concentration by 50-60% in the presence of 7% proteins (4% albumin (w/w), 2% fibrinogen (w/w), 1% globulins (w/w)). In human serum, the free drug reduction was 35-70% with the same 50:50 liposomes (0.72 mg lipid/mL). The liposomal systems were equally efficient at sequestering nortriptyline, which is a major metabolite of amitriptyline. The drug binding to liposomes in the presence of serum proteins is also quick and reversible and the likely mechanism of drug sequestration is adsorption of drug on the surface of liposomes. Accordingly, the drug uptake increases with increased charge and lipid loading. Even though the serum proteins reduced the effectiveness of the liposomes at sequestering the drug, the 50:50 DMPC:DOPG liposomes may be effective at treating amitriptyline overdose patients.