Clinical and ECG Effects of Escitalopram Overdose

Escitalopram-induced QTc prolongation and its relationship with KCNQ1, KCNE1, and KCNH2 gene polymorphisms

BACKGROUND

Escitalopram can cause prolongation of the QT interval on the electrocardiogram (ECG). However, only some patients get pathological QTc prolongation in clinic. We investigated the influence of KCNQ1, KCNE1, and KCNH2 gene polymorphisms along with clinical factors on escitalopram-induced QTc prolongation.

METHODS

A total of 713 patients prescribed escitalopram were identified and had at least one ECG recording in this retrospective study. 472 patients with two or more ECG data were divided into QTc prolongation (n = 119) and non-prolongation (n = 353) groups depending on the threshold change in QTc of 30 ms above baseline value (∆QTc ≥ 30 ms). 45 patients in the QTc prolongation group and 90 patients in the QTc non-prolongation group were genotyped for 43 single nucleotide polymorphisms (SNPs) of KCNQ1, KCNE1, and KCNH2 genes.

RESULTS

Patients with QTc prolongation (∆QTc ≥ 30 ms) got higher escitalopram dose (10.3 mg) than patients without QTc prolongation (9.4 mg), although no significant relationship was found between QTc interval and escitalopram dose in the linear mixed model. Patients who were older/coronary disease/hypertension or carried with KCNE1 rs1805127 C allele, KCNE1 rs4817668 C allele, KCNH2 rs3807372 AG/GG genotype were significantly at risk for QTc prolongation (∆QTc ≥ 30 ms). Concomitant antipsychotic treatment was associated with a longer QTc interval.

LIMITATIONS

A relatively small sample size and lack of the blood concentration of escitalopram restricted the accurate relationship between escitalopram dose and QTc interval.

CONCLUSION

Our study revealed that KCNQ1, KCNE1, and KCNH2 gene polymorphisms along with clinical factors provide a complementary effect in escitalopram-induced QTc prolongation.

Ventricular fibrillation in a 21-year-old after inhalation of an isobutyl nitrite "popper" product

BACKGROUND

Alkyl nitrite analogs known as "poppers" have been inhaled recreationally for decades. They are available to be purchased from gas stations marketed as "nail polish remover not for human consumption". These rapid-onset, short-acting, vasodilators cause the user to experience euphoria, dizziness, tachycardia and flushing. While chronic use may lead to problems such as methemoglobinemia or neuropathy, nitrites rarely lead to acute life-threatening side effects such as ventricular dysrhythmias.

CASE REPORT

We report a case of ventricular fibrillation cardiac arrest in a 21-year-old male after inhaling from a solution labeled to contain isobutyl nitrite, a rarely reported adverse effect of "popper" use. The product was analytically confirmed to contain mainly isobutyl alcohol, volatile hydrocarbons, and isobutyl nitrite, as well as smaller quantities of other substances. The patient was also prescribed escitalopram and hydroxyzine may have contributed. Return of spontaneous circulation was achieved in the field after initiation of CPR and defibrillation. He was found to have no clear predisposition to arrythmias during his care or on follow up.

CONCLUSION

Alkyl nitrite "popper" users and clinicians should be aware that products labeled to contain nitrites may contain volatile hydrocarbons along with nitrites and have the potential to cause arrhythmia.

QTc Prolongation in Poison Center Exposures to CredibleMeds List of Substances with "Known Risk of Torsades de Pointes"

Many drugs carry some risk of QT interval prolongation, which can lead to life-threatening dysrhythmias including Torsades de Pointes (TdP). CredibleMeds.org identifies medications categorized as "Known Risk of TdP" but does not stratify risk in acute supratherapeutic ingestions. We sought to determine the proportion of cases exhibiting QTc prolongation and life-threatening dysrhythmias including ventricular tachycardia (VT)/ventricular fibrillation (VF), TdP, and asystole in patients exposed to these substances. Retrospective chart review of cases reported to our Regional Poison Center from 2014 to 2019 of exposures to one or more of the "Known Risk" substances was performed. Demographics, therapies, clinical effects, and medical outcome for each case were analyzed. There were 1125 exposures, of which 760 had a documented QTc interval. QTc ≥ 500 ms was reported in 138 (18.2%) of the 760 cases. The most common "Known Risk" substances were citalopram, escitalopram and cocaine. Although not in the "Known Risk" category, mirtazapine, amitriptyline, diphenhydramine, and trazodone had a statistically significant association with QTc > 500 ms. Life-threatening dysrhythmias occurred in 13 cases, with VT/VF in 6 of the 760 (0.8%) cases, and one case of TdP. Flecainide (OR 11.1, 95% CI 2.2-55.8) and methadone (OR 7.1, 95% CI 2.1-23.4) were associated with increased risk of all life-threatening dysrhythmias. Exposures to medications on the Credible Meds list of "Known Risk of TdP" QTc prolongation is common, but life-threatening dysrhythmias are rare. Mirtazapine, amitriptyline, diphenhydramine, and trazodone were associated with prolonged QTc. Flecainide and methadone had the highest associated risk of life-threatening dysrhythmias.

Systematic review and meta-analysis on the therapeutic reference range for escitalopram: Blood concentrations, clinical effects and serotonin transporter occupancy

INTRODUCTION

A titration within a certain therapeutic reference range presupposes a relationship between the blood concentration and the therapeutic effect of a drug. However, this has not been systematically investigated for escitalopram. Furthermore, the recommended reference range disagrees with mean steady state concentrations (11-21 ng/ml) that are expected under the approved dose range (10-20 mg/day). This work systematically investigated the relationships between escitalopram dose, blood levels, clinical effects, and serotonin transporter occupancy.

METHODS

Following our previously published methodology, relevant articles were systematically searched and reviewed for escitalopram.

RESULTS

Of 1,032 articles screened, a total of 30 studies met the eligibility criteria. The included studies investigated escitalopram blood levels in relationship to clinical effects (9 studies) or moderating factors on escitalopram metabolism (12 studies) or serotonin transporter occupancy (9 studies). Overall, the evidence for an escitalopram concentration/effect relationship is low (level C).

CONCLUSION

Based on our findings, we propose a target range of 20-40 ng/ml for antidepressant efficacy of escitalopram. In maintenance treatment, therapeutic response is expected, when titrating patients above the lower limit. The lower concentration threshold is strongly supported by findings from neuroimaging studies. The upper limit for escitalopram's reference range rather reflects a therapeutic maximum than a tolerability threshold, since the incidence of side effects in general is low. Concentrations above 40 ng/ml should not necessarily result in dose reductions in case of good clinical efficacy and tolerability. Dose-related escitalopram concentrations in different trials were more than twice the expected concentrations from guideline reports.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=215873], identifier [CRD42020215873].

Serotonin Toxicity in Children and Adolescents: A Systematic Review and Meta-Analysis of Cases

Objectives: Serotonin toxicity is a state of central nervous system (CNS) excitation classically featuring altered mental status, neuromuscular excitation, and autonomic instability. While retrospective studies and reviews have characterized serotonin toxicity in adults, there have been no systematic reviews of serotonin toxicity in pediatric populations. The goal of this review was to use published case reports to describe serotonin toxicity in pediatric patients and to consider the impact of age on clinical presentation. Methods: A search for case reports of serotonin toxicity in patients younger than 18 years was conducted. Cases were systematically screened for inclusion using serotonin toxicity diagnostic tools, and a meta-analysis of case characteristics was conducted. Results: Sixty-six cases of serotonin toxicity in pediatric patients were reviewed. Only 56.1% met diagnostic criteria for serotonin toxicity on all three of the most commonly used diagnostic tools. Antidepressants were found to be the most common trigger of toxicity, implicated in 78.8% of cases. While onset of toxicity was rapid following overdose, toxicity was more likely to be delayed in the setting of medication titration (71.8% vs. 0%, p < 0.0001). Signs of neuromuscular excitation were prevalent, occurring in 92.4% of cases with 81.8% showing the full triad of neuromuscular symptoms, altered mental status, and autonomic instability. The only age-related differences occurred in relation to activation symptoms (more likely to be reported in children than in adolescents) and seizures (less likely to be reported in children than in adolescents or toddlers). Treatment was primarily supportive in nature, although 25.8% of patients received cyproheptadine. In all but one reviewed case, the patient survived. Conclusions: The presentation of serotonin toxicity in the pediatric population is similar to that seen in adults. Treatment is supportive with most patients achieving full recovery. Further exploration of the age-related differences in serotonin activity within the CNS is needed.

Toxicology of Psychoactive Substances

A trend in the increasing use of prescription psychoactive drugs (PADs), including antidepressants, antipsychotics, and mood stabilizers, has been reported in the United States and globally. In addition, there has been an increase in the production and usage of illicit PADs and emergence of new psychoactive substances (NPSs) all over the world. PADs pose unique challenges for critical care providers who may encounter toxicology issues due to drug interactions, side effects, or drug overdoses. This article provides a summary of the toxicologic features of commonly used and abused PADs: antidepressants, antipsychotics, mood stabilizers, hallucinogens, NPSs, caffeine, nicotine, and cannabis.

Drug-specific risk of severe QT prolongation following acute drug overdose

Background: Severe QT prolongation (SQTP) has been identified as a strong predictor of adverse cardiovascular events in acute drug overdose, but drug-specific causes of SQTP in the setting of acute drug overdose remain unclear. We aimed to perform the most definitive study to date describing drug-specific risk of SQTP following acute drug overdose.Methods: This was a prospective multicenter cohort study at >50 hospital sites across the US using the ToxIC Registry between 2015 and 2018. Inclusion criteria were adults (≥18 years) receiving medical toxicology consultation for acute drug overdose. The primary outcome was SQTP, which was defined using the computer automated Bazett QT correction (QTc) on the ECG with the previously validated cut point of 500 milliseconds. Mean difference in QTc was also calculated for specific drugs. Drugs associated with SQTP were analyzed using multivariable logistic regression to control for known confounders of QT risk (age, sex, race, cardiac disease).Results: From 25,303 patients screened, 6473 met inclusion criteria with SQTP occurring in 825 (13%). Drugs associated with increased adjusted odds of SQTP included Class III antidysrhythmics (sotalol), sodium channel blockers (amitriptyline, diphenhydramine, doxepin, imipramine, nortriptyline), antidepressants (bupropion, citalopram, escitalopram, trazodone), antipsychotics (haloperidol, quetiapine), and the antiemetic serotonin antagonist ondansetron.Conclusions: This large US cohort describes drug-specific risk of SQTP following acute drug overdose. Healthcare providers caring for acute drug overdoses from any of these implicated drugs should pay close attention to cardiac monitoring for occurrence of SQTP.

Comparative risk of Selective Serotonin Reuptake Inhibitors (SSRIs)-induced nausea among Chinese senile depression patients: A network meta-analysis of randomized-controlled trials

OBJECTIVES

To compare the therapeutic effect of 6 SSRIs among the Chinese senile depression patients. And drug-induced nausea leads to low compliance in elderly depression patients in China, it is urgent to assess the safety of 6 SSRIs with respect to induced-nausea among the Chinese senile depression patients.

METHOD

In the present study, a network of meta-analysis was conducted to assess the efficacy of 6 SSRIs among the Chinese senile depression patients, in addition, the safety of 6 SSRIs with respect to induced-nausea among the Chinese senile depression patients was also evaluated. PubMed, Embase databases, WanFang, CNKI, ChongqingWeiPu were searched for the related articles. The primary outcome of this study were the number of effective cases of SSRIs and the number of cases of nausea caused by SSRIs in Chinese elderly depressed patients. Odds ratios (ORs) and corresponding 95% confidence intervals(95%CIs) were calculated within pairwise and network meta-analysis.

RESULTS

Twenty eight trials were identified, including 2246 patients, the network meta-analysis indicated that Escitalopram was associated with a lower risk of nausea compared Paroxetine (odds ratios 0.49, 95%CI = 0.34-0.69) when they were used in Chinese elderly depressed patients. Escitalopram also exhibited distinct advantages compared other SSRIs.In terms of drug efficacy, Escitalopram was significantly superior to Paroxetine (OR = 2.26, 95%CI = 1.55-3.37).

CONCLUSION

The rank of SSRIs with respect to induced-nausea was: Combination of EP > Fluoxetine > Paroxetine > Citalopram > Sertraline > Fluvoxamine > Escitalopram, respectively.

Comparative cardiovascular safety of selective serotonin reuptake inhibitors (SSRIs) among Chinese senile depression patients: A network meta-analysis of randomized controlled trials

BACKGROUND

Senile depression patients in China usually present with a higher risk of coronary heart disease that may trigger cardiac death. Selective serotonin reuptake inhibitors (SSRIs) were the most prescribed antidepressants in China; the cardiovascular safety of SSRIs when used in Chinese senile depression patients has not been evaluated.

METHODS

A network of meta-analysis was conducted to fill the objectives. PubMed, Embase databases, and 2 Chinese language electronic databases WANFANG and CNKI were searched for the related articles. The primary outcome of the present study was the number of cardiovascular reactions when each SSRI drug was used among senile depression patients in China. Odds ratios (ORs) and corresponding 95% confidence intervals (95% CIs) were calculated within pairwise and network meta-analysis.

RESULTS

Fifteen trials were identified, including 1432 patients; the network meta-analysis showed that Chinese senile depression patients treated by Escitalopram were associated with a lower risk of cardiovascular reaction (CDR) than Paroxetine (ORs 0.37, 95% CI 0.14-0.37). Escitalopram also exhibited distinct advantages compared with other SSRIs. The rank of SSRIs with respect to cardiovascular safety was Escitalopram > Sertraline > Citalopram > Paroxetine > Fluoxetine, respectively.

CONCLUSION

Escitalopram exhibited distinct advantages compared with other SSRIs, while Fluoxetine had the biggest cardiovascular reaction probability.

[A retrospective historical study evaluating the safe use of current antidepressants in cardiology practice]

AIM

To confirm the data available in the literature on the cardiac safety of antidepressants.

SUBJECTS AND METHODS

The archival data of 146 case histories were retrospectively analyzed. A study sample consisted of 96 cardiac inpatients regularly taking an antidepressant for more than 3 days during treatment for the underlying cardiovascular disease. The safe use of antidepressants was evaluated in terms of initial electrocardiogram (ECG) QTc interval changes, systolic and diastolic blood pressures (BP) (SBP and DBP), heart rate (HR), and hemorrhagic complications. The data obtained over periods of 3- and 6-8 days were analyzed.

RESULTS

The sample showed no clinically significant ECG QTc interval changes when taking regularly antidepressants within 8 days. Analysis of the dynamics of BP and HR in patients receiving antidepressants revealed no statistically significant differences in these indicators before and 3 and 6-8 days after drug administration. No case of hemorrhagic complications was seen in the study group taking antidepressants.

CONCLUSION

The investigation generally confirms the high cardiac safety of new-generation antidepressants within at least the first week of therapy. Noteworthy are the low daily drug dosages (relatively specified in the instructions) that are sufficient for most cardiac patients with depressive disorders and an additional factor for minimizing adverse reactions.

Stress, anxiety and depression in heart disease patients: A major challenge for cardiac rehabilitation

Cardiovascular events and emotional disorders share a common epidemiology, thus suggesting fundamental pathways linking these different diseases. Growing evidence in the literature highlights the influence of psychological determinants in somatic diseases. A patient's socio-economic aspects, personality traits, health behavior and even biological pathways may contribute to the course of cardiovascular disease. Cardiac events often occur suddenly and the episode can be traumatic for people not prepared for such an event. In this review of the literature, the authors tackle the question of psychobiological mechanisms of stress, in a pathophysiological approach to fundamental pathways linking the brain to the heart. Various psychological, biological and genetic arguments are presented in support of the hypothesis that various etiological mechanisms may be involved. The authors finally deal with biological and psychological strategies in a context of cardiovascular disease. Indeed, in this context, cardiac rehabilitation, with its global approach, seems to be a good time to diagnose emotional disorders like anxiety and depression, and to help people to cope with stressful events. In this field, cardiac rehabilitation seems to be a crucial step in order to improve patients' outcomes, by helping them to understand the influence of psychobiological risk factors, and to build strategies in order to manage daily stress.

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.

The pharmacokinetics of sertraline in overdose and the effect of activated charcoal

AIMS

To investigate the pharmacokinetics (PK) of sertraline in overdose and the effect of single dose activated charcoal (SDAC).

METHODS

Patients presenting to a toxicology unit with sertraline overdoses had demographic and clinical information recorded, and serial serum collected for measurement of sertraline concentrations. Monolix® version 4.2 was used to develop a population PK model of sertraline overdose and the effect of SDAC. Uncertainty in dose time was accounted for by shifting dose time using lag time with between subject variability (BSV). BSV on relative fraction absorbed was used to model uncertainty in dose.

RESULTS

There were 77 timed sertraline concentrations measured in 28 patients with sertraline overdoses with a median dose of 1550 mg (250-5000 mg). SDAC was given to seven patients between 1.5 and 4 h post-overdose. A one compartment model with lag time of 1 h and first order input and elimination adequately described the data. Including BSV on both lag time and relative fraction absorbed improved the model. The population PK parameter estimates for absorption rate constant, volume of distribution and clearance were 0.895 h(-1) , 5340 l and 130 l h(-1) , respectively. The calculated half-life of sertraline following overdose was 28 h (IQR 19.4-30.6h). When given up to 4 h post-overdose, SDAC significantly increased the clearance of sertraline by a factor of 1.9, decreased the area under the curve and decreased the maximum plasma concentration (Cmax ).

CONCLUSIONS

Sertraline had linear kinetics in overdose with parameter values similar to those in therapeutic use. SDAC is effective in increasing clearance when given 1.5 to 4 h post-overdose.

A prospective cohort study of trends in self-poisoning, Newcastle, Australia, 1987-2012: plus ça change, plus c'est la même chose

OBJECTIVE

To examine inhospital mortality and morbidity associated with self-poisoning with different drug classes over an extended period.

DESIGN, SETTING AND PARTICIPANTS

A prospective cohort study over 26 years (1987-2012) with limited follow-up of patients presenting consecutively to a primary and tertiary referral toxicology centre covering Newcastle, Lake Macquarie and Port Stephens, Australia.

MAIN OUTCOME MEASURES

Hospital length of stay, types of drugs ingested, intensive care unit (ICU) admission, requirement for ventilation, inhospital deaths and rates of antidepressant drug use in Australia.

RESULTS

Over the study period, there were 17 266 admissions of patients poisoned by 34 342 substances (16 723 drugs available only on prescription). The median length of stay was 16 hours, 12.2% of patients (2101/17 266) were admitted to an ICU, 7.4% (1281/17 266) were ventilated and 78 (0.45%) died in hospital. Patient demographics, social and psychiatric factors remained stable over the 26-year period, but case fatality decreased (from 0.77% [15/1955] to 0.17% [7/4060]) as did ICU admissions (19.2% [376/1955] to 6.9% [280/4060]), ventilation (13.7% [268/1955] to 4.8% [193/4060]) and LOS. The most frequently ingested substances were alcohol, benzodiazepines, paracetamol, antidepressants and antipsychotics. There was a substantial fall in some highly toxic drugs (tricyclic antidepressants, barbiturates, conventional antipsychotics and theophylline), but increases in less toxic selective serotonin reuptake inhibitors, serotonin-noradrenaline reuptake inhibitors and paracetamol. A greater than sixfold increase in community antidepressant use was accompanied by only minor changes in overall and antidepressant self-poisoning rates.

CONCLUSION

Over two decades, there were decreases in poisonings by many highly toxic drugs which were associated with substantial reductions in morbidity and inhospital deaths. Despite massive increases in the number of antidepressant prescriptions, neither rates of self-harm nor the proportion of antidepressant poisonings increased markedly.

CYP2C19 variation, not citalopram dose nor serum level, is associated with QTc prolongation

Recently, a FDA Safety Communication warned of a dose-dependent risk for QTc prolongation with citalopram, which is metabolized by CYP2C19 of the cytochrome P450 system. We investigate associations between citalopram and escitalopram dose, serum concentration, CYP2C19 phenotype, and QTc. We undertook a retrospective chart review of citalopram or escitalopram patients with the inclusion criteria of consistent medication dose, CYP2C19 phenotype (extensive metabolizers [EM], intermediate metabolizers [IM], poor metabolizers [PM]), and QTc interval on ECG. We further identified 42 citalopram users with citalopram serum concentration measurements and ECG. Regression and one-way ANOVA were used to examine the relationship between citalopram dose, citalopram serum concentration, CYP2C19 phenotype, and QTc interval. Of 75 citalopram patients, the EM group had significantly shorter QTc intervals than a combined IM+PM group (427.1±23.6 ms vs. 440.1±26.6 ms, one-tailed t-test, p=0.029). In the 80 escitalopram cohort, there was no significant difference in QTc between phenotype groups. There was no statistical correlation between citalopram (p=0.62) or escitalopram (p=0.30) dose and QTc. QTc was not associated with citalopram serum level (p=0.45). In contrast to the FDA warning, this study found no association between citalopram/escitalopram dose and QTc. However, PM of the drug tended to have longer QTc intervals. Our findings suggest cytochrome P450 genotyping in select patients may be helpful to guide medication optimization while limiting harmful effects.

Risk factors for QT prolongation associated with acute psychotropic drug overdose

BACKGROUND

Antipsychotic/Antidepressant use is a risk factor for QT interval (QT) prolongation and sudden cardiac death. However, it is unclear which drugs are risk factors for QT prolongation and torsades de pointes in cases of psychotropic drug overdose.

METHODS

After correction of QT data by Bazett formula (QTc), QTc was classified into 3 categories (QTc<440 milliseconds, 440 milliseconds≤QTc<500 milliseconds, and QTc≥500 milliseconds), and the blood concentration of each drug was classified as not detected, therapeutic range, or toxic range. The association of the blood concentration of each drug with QTc was analyzed using the ordinal logistic regression model. Drugs that induced QT-heart rate pairs higher than the at-risk line of Isbister's QT-heart rate nomogram (QT nomogram) were further analyzed using the binomial logistic regression model.

RESULTS

A total of 649 patients were enrolled in the study. The independent risk factors for QTc prolongation were therapeutic and toxic range of phenotiazine antipsychotic drug (therapeutic range: odds ratio [OR], 1.56 [P=.039]; toxic range: OR, 3.85 [P<.001]), and toxic range of cyclic antidepressants (OR, 2.39; P=.018). In addition, toxic range of phenotiazine antipsychotic drug (OR, 3.87; P=.012) and tricyclic antidepressants (OR, 4.94; P<.001) were risk factors for QT higher than the at-risk line of the QT nomogram.

CONCLUSIONS

The possibility of QT prolongation and torsades de pointes due to overdose of phenotiazine antipsychotic drug or tricyclic antidepressants requires particular consideration.

Do serotonin reuptake inhibitors worsen outcome of patients referred to the emergency department for deliberate multi-drug exposure?

Incidence of poisonings with serotonin reuptake inhibitors (SRIs) is growing. SRI toxicity is considered low, but its actual impact in multi-drug poisonings remains unclear. Our objective was to evaluate the consequences of SRI exposure in patients referred to the emergency department (ED) for deliberate multi-drug exposure. Patients admitted for multi-drug exposure involving at least one SRI were matched with patients who did not ingest any SRI, according to age, gender, type of drug and ingested doses. Features of serotonin syndrome according to Sternbach's criteria and Hunter's serotonin toxicity criteria were evaluated from records. In 4 years, 148 SRI-exposed patients were included and compared to 296 matched controls. The SRIs mainly involved were escitalopram (22%), venlafaxine (20%), fluoxetine (19%), citalopram (15%) and paroxetine (11%). Serotonin syndrome was diagnosed in one patient, but actually occurred in five SRI-exposed patients based on the retrospective evaluation of records. Twenty patients (14%) exhibited one or more serotonin syndrome criteria. At least two of 11 of Sternbach's criteria and two of nine of Hunter's serotonin toxicity criteria were missing in each chart. Using a conditional logistic regression analysis, seizures (p = 0.04) and serotonin syndrome (p = 0.01 based on Sternbach's criteria and p = 0.004 based on Hunter's serotonin toxicity criteria) more frequently occurred in SRI-exposed patients. Requirement for mechanical ventilation was significantly increased (p = 0.03), although admission to the intensive care unit was not. In multi-drug-poisoned patients admitted to the ED, exposure to SRIs significantly increases the risk of seizures and requirement for mechanically ventilation. Diagnosis of serotonin syndrome remains insufficient justifying improved training.

Drug-Induced QT Prolongation as a Result of an Escitalopram Overdose in a Patient with Previously Undiagnosed Congenital Long QT Syndrome

We present a case of drug-induced QT prolongation caused by an escitalopram overdose in a patient with previously undiagnosed congenital LQTS. A 15-year-old Caucasian female presented following a suicide attempt via an escitalopram overdose. The patient was found to have a prolonged QT interval with episodes of torsades de pointes. The patient was admitted to the telemetry unit and treated. Despite the resolution of the torsades de pointes, she continued to demonstrate a persistently prolonged QT interval. She was seen by the cardiology service and diagnosed with congenital long QT syndrome. This case illustrates the potential for an escitalopram overdose to cause an acute QT prolongation in a patient with congenital LQTS and suggests the importance of a screening electrocardiogram prior to the initiation of SSRIs, especially in patients at high risk for QT prolongation.

[Citalopram, escitalopram and prolonged QT: warning or alarm?]

The alerts issued by regulatory agencies on the potential cardiac toxicity of citalopram and escitalopram have caused alarm among clinicians. A review of the data concerning this topic shows that the alarm should be limited to patients with a history of syncope or poisoning. As a precautionary measure, an electrocardiogram should be performed on elderly patients.

Mirtazapine overdose is unlikely to cause major toxicity

OBJECTIVE

There is limited information on mirtazapine overdose, but cases of severe effects (seizures, serotonin toxicity and coma) have been reported. We aimed to investigate the clinical effects and complications of mirtazapine overdose.

METHODS

This was an observational case series of mirtazapine overdoses (> 120 mg) identified from admissions to a toxicology unit between January 1987 and August 2013. Demographic information, details of ingestion, clinical effects, ECG parameters (HR, QT and QRS), and length of stay were extracted from a clinical database.

RESULTS

From 267 mirtazapine overdoses, there were 89 single-agent mirtazapine ingestions and 178 cases where mirtazapine was taken with at least one other drug. The median age of the 89 single-agent mirtazapine ingestions was 36 years [interquartile range (IQR): 26-49 years; Range: 15-81 years]; 45 were female (51%). The median ingested dose was 420 mg (IQR: 270-750 mg; Range: 150-1350 mg) and 41 patients (46%) had a Glasgow coma score (GCS) < 15, but the minimum GCS was 10. There were no seizures, serotonin toxicity or delirium. Tachycardia occurred in 29 patients (33%) and hypertension in 32 patients (36%). The median QRS was 80 ms (Range: 80-120 ms) and there were no cases with QT prolongation. There were no arrhythmias and no deaths. The median length of stay was 14 h (IQR: 8.8-18.2 h; Range:2.2-75 h). No single-agent mirtazapine patient was admitted to intensive care. The 178 patients taking co-ingestants had more severe toxicity depending on the co-ingested drug.

CONCLUSION

Mirtazapine appears to be relatively benign in overdose, associated with tachycardia, mild hypertension and mild CNS depression not requiring intervention.

The cardiovascular safety profile of escitalopram

The cardiovascular effects of escitalopram were examined in a large group of participants in double-blind, randomized, placebo-controlled studies. Escitalopram (n=3298) was administered at doses between 5 and 20mg/day. Patients were treated in acute (8-12 weeks) and long-term (24 weeks) studies. Assessment of cardiovascular safety included heart rate, blood pressure (BP), treatment-emergent adverse events (TEAEs) and electrocardiograms (ECGs). In the short-term, there was a small, but statistically significant 2 beats per minute decrease in heart rate with escitalopram compared with placebo. The difference compared to placebo in systolic or diastolic BP was not clinically or statistically significant. Valid ECG assessments at both baseline and last assessment were available for 2407 escitalopram patients and 1952 placebo patients. Escitalopram-placebo differences in mean changes in ECG values were not clinically meaningful. The mean difference to placebo in the corrected QT [Fridericia's (QTcF)] interval was 3.5 ms (all escitalopram doses); 1.3 ms (escitalopram 10mg) and 1.7 ms (escitalopram 20mg) (p=0.2836 for 10 versus 20 mg). One out of 2407 escitalopram patients had a QTcF interval >500 ms and a change from baseline >60 ms. The incidence and types of cardiac-associated adverse events were similar between patients treated for 8-12 weeks with placebo (2.2%) or escitalopram (1.9%) and for 24 weeks with placebo (2.7%) or escitalopram (2.3%). Analyses of data from long-term studies and studies of the elderly showed similar results. In conclusion, these data demonstrate that escitalopram, like other SSRIs, has a statistically significant effect on heart rate and no clinically meaningful effect on ECG values, BP, with a placebo-level incidence of cardiac-associated adverse events.

Sodium channel blockade with QRS widening after an escitalopram overdose

INTRODUCTION

Escitalopram is rarely associated with prolongation of the QTc interval; however, there are no reported cases of QRS complex widening associated with escitalopram overdose. We report a case of a patient who presented with both QRS complex widening and QTc interval prolongation after an escitalopram overdose.

CASE

A 16-year-old girl presented to the emergency department after ingestion of escitalopram, tramadol/acetaminophen, and hydrocodone/acetaminophen. Laboratory results were significant for 4-hour acetaminophen 21.1 μg/mL. Serum electrolytes including potassium, magnesium, and calcium were all normal. Initial electrocardiogram (ECG) revealed a widened QRS with an incomplete right bundle branch pattern. After administration of 100-mEq sodium bicarbonate, a repeat ECG revealed narrowing of the QRS complex and a prolonged QTc interval. Magnesium sulfate 2 g intravenous and sodium bicarbonate drip were initiated. A repeat ECG, 1 hour after the second, revealed normalization of the QRS complex and QTc interval.

DISCUSSION

Prolongation of the QTc interval is an expected effect of escitalopram. Both escitalopram and citalopram are metabolized to the cardiotoxic metabolite S-didesmethylcitalopram and didesmethylcitalopram, respectively, which have been implicated in numerous cardiac abnormalities including widening of the QRS complex. Although never previously described with escitalopram, this mechanism provides a reasonable explanation for the QRS complex widening and incomplete right bundle branch block that occurred in our patient.

CONCLUSIONS

Both QRS complex widening and QTc interval prolongation should be monitored in cases of escitalopram and citalopram overdoses.

Predicting the requirement for N-acetylcysteine in paracetamol poisoning from reported dose

Context

There is contention over whether reported dose correlates with toxicity in paracetamol poisoning and risk assessment is currently based on serum paracetamol concentration compared to a nomogram, irrespective of reported dose.

Objective

To determine if reported dose predicts the need for N-acetylcysteine (NAC).

Methods

Data were taken from paracetamol overdoses presenting to a tertiary toxicology service. Age, sex, reported dose, ingestion time, timed paracetamol concentrations between 4 and 16 h, hepatotoxicity (peak alanine transaminase > 1000 U/L) and treatment (single dose-activated charcoal [SDAC] and NAC) were analysed. Data were analysed within a repeated measures logistic regression framework using NONMEM (ver 7.2). The primary outcome was administration of NAC, which was determined based on a serum paracetamol concentration greater than the nomogram line.

Result

There were 1571 admissions in 1303 patients, with a median age of 27 years (12–96 years) and 1140 (73%) were females. The median dose was 10 g (1–100 g). The paracetamol concentration was above the nomogram line in 337 of 1571 (22%) patients. Patients presenting later (first paracetamol concentration between 7 and 16 h post-overdose) compared to those presenting earlier (4–7 h post-overdose) were more likely to have hepatotoxicity (5.5% vs. 0.4%; p < 0.0001), have a toxic paracetamol concentration (34% vs. 18%; p < 0.0001) and receive NAC (48% vs. 23%; p < 0.0001). SDAC reduced the probability of the paracetamol concentration being above the nomogram. Based on SDAC not being administered there was a 5% probability of requiring NAC at a dose of 6–9 g, a 10% chance of requiring NAC at a dose of 13–16 g, a 50% chance of requiring NAC at a dose of 30–34 g and a 90% chance for needing NAC at 48–50 g.

Conclusion

Reported dose was a good predictor of a toxic paracetamol concentration and SDAC reduced the probability of the concentration being above the nomogram. These predictions may assist in determining which patients could be started on NAC immediately.

Metabolic and toxicological considerations for obsessive-compulsive disorder drug therapy

INTRODUCTION

Obsessive-compulsive disorder (OCD) affects the daily life of the patients. Chronic nature of this disease and the need for long-term high-dose drug therapy for its maintenance increase the risk of metabolic and toxicological complications.

AREAS COVERED

In this concise article, the metabolic and toxicological aspects of major medication categories prescribed in OCD, such as serotonin-specific reuptake inhibitors, tricyclic antidepressant (clomipramine), serotonin-norepinephrine reuptake inhibitors, and atypical antipsychotics indicated in OCD (both Food and Drug Administration-approved and off-label) are discussed.

EXPERT OPINION

The most critical point in pharmacotherapy of OCD is the need for the high-dose and long-term use of drugs. In OCD, generally the higher doses of applicable drugs than those used in depression are required, often exceeding the recommended maximum dose. Moreover, such high doses should be given for at least 10 - 12 weeks to ensure the adequate treatment duration for the clinical effects to emerge. This long-term high-dose maintenance therapy increases the risk of drug toxicity and adverse effects. Physicians should take extra care in periodical assessment of signs and symptoms of metabolic and toxicological complications in patients. Subjective symptoms reported by patients should be carefully assessed and not attributed to obsessive nature of the patients.

Review on depression and coronary heart disease

The impact of psychological factors on somatic disorders - and vice versa - and the involvement of biological mechanisms in psychic disorders have generated considerable interest in recent years, notably thanks to cutting-edge investigation techniques (immunohistochemistry, functional imaging, genetics, etc.). In the field of psychosomatics, coronary heart disease (CHD) is a frequent co-morbidity of mental disorders, particularly mood disorders. Indeed, there is a bidirectional relationship between CHD and mood disorders, with a strong co-occurrence of the two diseases accompanied by a reciprocal worsening of the prognosis for the two conditions. Various epidemiological studies have shown that depression is a psychic risk factor for CHD and that CHD is present in almost 30% of patients with affective disorders. In this review of the literature, we tackle the crucial question of the diagnosis of depression during myocardial infarction. This clinical approach is essential given the underevaluation of this psychic problem. Then, various psychological, biological and genetic arguments are presented in support of the hypothesis that various aetiological mechanisms of the two disorders are partly shared. We finally deal with the treatment of depression in the context of CHD with its pharmacological and psychological specificities. In conclusion, this review reiterates the need for a multidisciplinary approach, which is necessary to understand, diagnose and then treat this frequent co-morbid condition of heart disease and depression.

Population pharmacokinetics and pharmacodynamics of escitalopram in overdose and the effect of activated charcoal

AIMS

To describe the pharmacokinetics and pharmacodynamics (PKPD) of escitalopram in overdose and its effect on QT prolongation, including the effectiveness of single dose activated charcoal (SDAC).

METHODS

The data set included 78 escitalopram overdose events (median dose, 140mg [10-560mg]). SDAC was administered 1.0 to 2.6 h after 12 overdoses (15%). A fully Bayesian analysis was undertaken in WinBUGS 1.4.3, first for a population pharmacokinetic (PK) analysis followed by a PKPD analysis. The developed PKPD model was used to predict the probability of having an abnormal QT as a surrogate for torsade de pointes.

RESULTS

A one compartment model with first order input and first-order elimination described the PK data, including uncertainty in dose and a baseline concentration for patients taking escitalopram therapeutically. SDAC reduced the fraction absorbed by 31% and reduced the individual predicted area under the curve adjusted for dose (AUC(i) /dose). The absolute QT interval was related to the observed heart rate with an estimated individual heart rate correction factor (α= 0.35). The heart rate corrected QT interval (QT(c) ) was linearly dependent on predicted escitalopram concentration [slope = 87ms/(mgl(-1) )], using a hypothetical effect-compartment (half-life of effect-delay, 1.0h). Administration of SDAC significantly reduced QT prolongation and was shown to reduce the risk of having an abnormal QT by approximately 35% for escitalopram doses above 200mg.

CONCLUSIONS

There was a dose-related lengthening of the QT interval that lagged the increase in drug concentration. SDAC resulted in a moderate reduction in fraction of escitalopram absorbed and reduced the risk of the QT interval being abnormal.

The Toxicology Investigators Consortium (ToxIC) Registry

Many medical toxicologists are interested in participating in a practice-based, multicenter research and toxicosurveillance network. In 2009, the American College of Medical Toxicology established the Toxicology Investigators Consortium (ToxIC). One facet of ToxIC is a registry that can be used for surveillance of new or old agents, assessment of treatment decisions, and the creation of new research questions. This paper describes the development of and the initial experiences with this registry of toxicology patients. In November 2009, ACMT invited members to participate in a new registry of cases evaluated and cared for by practicing medical toxicologists who provide direct hands-on clinical care. A password-protected, encrypted, online registry data site was created to upload a newly developed electronic case report form (CRF) on registry patients. The CRF includes demographics; encounter circumstances; agent; syndrome, symptoms, and signs; and treatment. A test version at four sites began in January 2010, seven additional sites were added in March 2010 for the beta phase, and the registry was opened to all interested US medical toxicology practices in April 2010. The CRF underwent continuous modifications based upon frequent feedback from and discussion among the participants. Thirty-three toxicology practice sites, encompassing 56 hospitals and clinics, have entered data into the ToxIC Registry. During the first 14 months of data collection, 5,412 patients were entered. The experience thus far demonstrates that the creation of this registry is feasible and constitutes a potentially powerful toxicosurveillance and robust research tool.

A question about the potential cardiac toxicity of escitalopram

Previous reviews have focused on the potential cardiac toxicity of the racemic drug citalopram (Celexa(®)). Evaluating the safety of escitalopram (Lexapro(®)) is an important issue to consider, since it is the S-enantiomer of citalopram. Escitalopram has a small effect on the QTc interval. A prolonged QTc was seen in 2% to 14% of escitalopram overdose cases, without serious cardiac sequelae. The QTc prolongation effect of citalopram in beagle dogs has been attributed to the minor metabolite racemic didemethylcitalopram (DDCT). Whether the escitalopram minor metabolite S-DDCT has this effect is not known. Concentrations of S-DDCT are lower than DDCT, but for a broad range of doses of escitalopram and citalopram, the S-DDCT and DDCT concentrations are well below the QTc prolonging concentrations reported in dogs. There is no strong evidence from human and animal studies that the cardiac safety of escitalopram is significantly superior to that of citalopram.

A critical evaluation of the cardiac toxicity of citalopram: part 1

In August 2011, the U.S. Food and Drug Administration issued a safety announcement that the antidepressant drug citalopram (Celexa(®)) should not be used at dosages greater than 40 mg per day (or greater than 20 mg per day for patients 60 and older) because it can cause abnormal changes in the electrical activity of the heart. This warning was based on the results of a "thorough QT/QTc study" of citalopram and on post-marketing reports of QT prolongation and torsade de pointes in some patients taking the drug. The statistically significant results from the "thorough QT/QTc study" were small in magnitude, and their clinical significance is questionable. Additional electrocardiogram analyses from other studies do not confirm these findings. Nearly 600 cases of citalopram overdoses have been described. Although citalopram overdose is not entirely "cardiac safe," only a proportion of patients develop QTc prolongation without serious cardiac sequelae and no deaths. Three studies comparing citalopram overdoses to other antidepressant overdoses do not demonstrate clinically meaningful differences in cardiotoxic effects.

Amisulpride overdose is frequently associated with QT prolongation and torsades de pointes

This study aimed to describe the effects of the antipsychotic amisulpride in overdose, including the frequency of QT prolongation and torsades de pointes. Cases of amisulpride overdose (>1 g) were recruited from 2 state poison centers and a tertiary toxicology unit over 5 years. A 1-page clinical research form was used to collect clinical information. Copies of all electrocardiograms were obtained. Electrocardiogram parameters (QRS and QT intervals) were manually measured as previously described, and plots of QT-heart rate (HR) pairs were compared with the QT nomogram. There were 83 patients with amisulpride overdoses with a median age of 29 years (interquartile range [IQR], 23-40 years), and 42 (51%) were female. The median dose ingested was 6 g (IQR, 3-13 g, range, 1.2-120 g). The median HR was 66 beats/min (IQR, 60-81 beats/min). Bradycardia occurred in 20 cases (24%), and hypotension in 19 (23%). From 440 electrocardiograms (average of 5 per case; range, 1-15), an abnormal QT-HR pair occurred in 61 cases (73%). Torsades de pointes developed in 6 cases (7%), with doses of 4, 4.6, 18, 24, 32, and 80 g. The patient taking 32 g died after a cardiac arrest. Widened QRS did not occur except transient rate-dependent bundle-branch block in 3 cases. There were significant associations of bradycardia, hypokalemia, and hypocalcaemia, with QT prolongation and torsades de pointes. Central nervous system effects were uncommon with coma in 7 cases, seizures in 2, and dystonic reactions in 2. Amisulpride overdose commonly causes QT prolongation, bradycardia, and hypotension. Torsades de pointes occurred commonly enough to suggest that amisulpride is highly cardiotoxic in overdose.

Escitalopram causes fewer seizures in human overdose than citalopram

CONTEXT

Seizures are a recognized complication of acute overdose with the racemic (1:1 ratio of R- and S-enantiomers) selective serotonin reuptake inhibitor antidepressant citalopram.

OBJECTIVE

We tested the hypothesis that escitalopram (the therapeutically active S-enantiomer of citalopram) causes fewer seizures in overdose than citalopram at comparable doses of the S-enantiomer.

METHODS

Multicenter retrospective review of cases with citalopram and escitalopram overdose reported to German, Austrian, and Swiss Poisons Centers between 1997 and 2006.

RESULTS

316 citalopram and 63 escitalopram cases were analyzed. Somnolence, nausea, vomiting, tachycardia, QT prolongation, and tremor occurred with similar frequency in both groups. There was a striking difference in the frequency of single and multiple seizures: 43 cases (13.5%) in the citalopram group and 1 case (1.6%) with a single seizure in the escitalopram group (p=0.0065).

DISCUSSION AND CONCLUSIONS

At comparable ingested doses of the S-enantiomer, the symptom profile for citalopram and escitalopram intoxications is similar except for seizures that occur more frequently in citalopram than in escitalopram poisoning.