Serotonin syndrome after electroconvulsive therapy in a patient on trazodone, bupropion, and quetiapine: a case report

Recurrent Serotonin Syndrome After Ketamine-assisted Electroconvulsive Therapy: A Case Report and Review of the Literature

Serotonin (5-HT) syndrome (SS) consists of changes in mental status as well as autonomic and neuromuscular changes. Though not well understood, serotonergic pathways have been implicated in the mechanism of action of electroconvulsive therapy (ECT). Ketamine has been used as an induction agent in ECT and as therapy for treatment-resistant depression. Utilizing a case report and literature review, we explored the underlying serotonergic mechanisms of ECT and ketamine by which a syndrome of serotonin toxicity may be precipitated. We describe the case of a 72-year-old woman who developed recurrent SS on 2 occasions in similar circumstances involving the administration of ketamine for ECT. In our literature review, we found 5 cases in which SS was associated with ECT and 1 case linking ketamine to SS. There is emerging evidence that the mechanism of ECT involves 5-HT1A and 5-HT2A receptors, the same receptors that are involved in SS. ECT can transiently increase the permeability of the blood-brain barrier, leading to increased levels of antidepressants in the brain. ECT can, therefore, enhance 5-HT transmission and the likelihood of SS in the presence of serotonergic agents. The effect of ketamine on 5-HT transmission is mediated by the glutamate α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor. Ketamine increases α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid activity in the medial prefrontal cortex, which leads to downstream 5-HT release through glutamate. Through this mechanism, ketamine can increase 5-HT transmission, leading to SS. To our knowledge, this is the only case report of recurrent SS with concurrent use of ECT and ketamine. As ketamine is frequently used in ECT and many patients undergoing ECT are on serotonergic medications, it is important to recognize ketamine as a potential risk factor for SS. There is no evidence for added efficacy when combining ECT and ketamine. Thus, one should proceed with caution when combining these treatments. The burgeoning use of ketamine in ambulatory settings makes it necessary to elucidate the risks, which we discuss further. More research is needed into the mechanisms of ketamine and ECT, specifically how the combination of these treatments influence 5-HT levels.

Factors associated with seizure development after bupropion overdose: a review of the toxicology investigators consortium

BACKGROUND

Bupropion is an aminoketone antidepressant. A major concern in bupropion toxicity is seizure activity, which can occur up to 24 h from ingestion. It is difficult to predict which patients will have seizures. The purpose of this study is to identify clinical features associate with seizure after bupropion overdose.

METHODS

We searched the Toxicology Investigators Consortium registry for a cases of poisoning by bupropion between January 1, 2014 and January 1, 2017 in patients aged 13-65. Demographic variables and clinical features were compared between patients who did and did not experience a seizure and presented as unadjusted odds ratios (OR). Multivariable logistic regression was used to calculate adjusted odds ratios (aOR) between clinical features and seizures.

RESULTS

There were 256 cases of bupropion overdose remaining after inclusion/exclusion criteria were applied. Clinical features associated with seizure were QTc >500 (OR = 3.4, 95% CI: 1.3-8.8, p = 0.012), tachycardia (p > 140) (OR = 1.9, 95% CI: 1-3.561, p = 0.05), and age 13-18 years (2.4, 95% CI: 1.3-4.3, p = 0.005). The mean QTc value for patients experiencing a seizure was 482 ms (N = 95 IQR: 59 ms) versus 454 ms (N = 103, IQR: 43) in patients who did not experience seizure, however, it was not possible to identify a QTc cutoff with sensitivity or specificity to predict seizures.

CONCLUSION

Based on our analysis of data from the ToxIC registry, age (13-18), tachycardia (p > 140) and QTc >500 ms are associated with seizures in bupropion overdose; however, a specific QTc value may not be a useful predictor of seizures.

Management of severe arterial hypertension associated with serotonin syndrome: a case report analysis based on systematic review techniques

Serotonin syndrome is thought to arise from serotonin excess. In many cases, symptoms are mild and self-limiting. But serotonin syndrome can become life threatening, when neuromuscular hyperexcitability spins out of control. Uncontainable neuromuscular hyperexcitability may lead to cardiovascular complications, linked to extreme changes in blood pressure. Currently, there is little guidance on how to control blood pressure in hyperserotonergic states. We report a case with treatment-resistant arterial hypertension, followed by a clinical review (using systematic review principles and techniques) of the available evidence from case reports published between 2004 and 2016 to identify measures to control arterial hypertension associated with serotonin syndrome. We conclude that classic antihypertensives may not be effective for the treatment of severe hypertension associated with serotonin syndrome. Benzodiazepines may lower blood pressure. Patients with severe hypertension not responding to benzodiazepines may benefit from cyproheptadine, propofol or both. In severe cases, higher cyproheptadine doses than currently recommended may be necessary.

Electrical weapons and excited delirium: shocks, stress, and serum serotonin

It has been suggested that a CEW (conducted electrical weapon) exposure could elicit a stress response that could cause ExDS (excited delirium syndrome). There are some parallels between the signs of ExDS and serotonin syndrome (SS). Electroconvulsive therapy raises serotonin levels and therefore provides a plausible link between CEW applications and elevated serotonin levels. This study was designed to determine whether a CEW exposure elevates serum serotonin. A total of 31 police academy cadets were exposed to a very broad-spread 5-s CEW stimulus from a TASER brand X26 CEW. Blood was drawn before and after the exposure and at 24 h post exposure to measure serum serotonin levels. Lactic acid and cortisol levels were also compared. Median serum serotonin levels were 30 IQR (21,46), 36 IQR (22,50), and 32 IQR (21,45) ng/mL before exposure, after exposure, and 24 h after exposure (NS by pooled comparisons). The increase from baseline to post-test serotonin (∆ median = +6, ∆ mean = +2.7) ng/mL was not significant by a paired T-test (p = .29) but was significant by the Wilcoxon signed-rank test (p = .037). The increase to post-test log serotonin was not significant by a paired T-test (p = .13) but was significant by the Wilcoxon test (p = .049). All serotonin levels remained within the normal reference range of 0-200 ng/mL. Post-hoc analysis demonstrated that the study was powered to detect a ½ SD change, in log serotonin, with a 90% likelihood. With a very-broad electrode spread, CEW exposure did not significantly raise serum serotonin levels.

General Anaesthesia Protocols for Patients Undergoing Electroconvulsive Therapy: Retrospective analysis of 504 sessions over a five-year period at a tertiary care hospital in Oman

OBJECTIVES

This study aimed to review general anaesthesia protocols for patients undergoing electroconvulsive therapy (ECT) at a tertiary care hospital in Oman, particularly with regards to clinical profile, potential drug interactions and patient outcomes.

METHODS

This retrospective study took place at the Sultan Qaboos University Hospital (SQUH), Muscat, Oman. The electronic medical records of patients undergoing ECT at SQUH between January 2010 and December 2014 were reviewed for demographic characteristics and therapy details.

RESULTS

A total of 504 modified ECT sessions were performed on 57 patients during the study period. All of the patients underwent a uniform general anaesthetic regimen consisting of propofol and succinylcholine; however, they received different doses between sessions, as determined by the treating anaesthesiologist. Variations in drug doses between sessions in the same patient could not be attributed to any particular factor. Self-limiting tachycardia and hypertension were periprocedural complications noted among all patients. One patient developed aspiration pneumonitis (1.8%).

CONCLUSION

All patients undergoing ECT received a general anaesthetic regimen including propofol and succinylcholine. However, the interplay of anaesthetic drugs with ECT efficacy could not be established due to a lack of comprehensive data, particularly with respect to seizure duration. In addition, the impact of concurrent antipsychotic therapy on anaesthetic dose and subsequent complications could not be determined.