Serotonin Syndrome After a Massive Overdose of Controlled-Release Paroxetine

Review article: Efficacy of cyproheptadine in the management of serotonin toxicity following deliberate self-poisoning - A systematic review

Serotonin toxicity is a potentially fatal condition caused by increased serotonergic activity in the central nervous system. Cyproheptadine, a serotonergic antagonist, is recommended for treatment; however, there is a lack of evidence to support its use. The present study aimed to evaluate the evidence for the use of cyproheptadine in the management of serotonin toxicity following deliberate self-poisoning. Publications from 2003 were identified by searching electronic databases Cochrane, MEDLINE, EMBASE and PsycINFO. The inclusion criteria for studies to be included were determined a priori and consisted of studies published in English (or where an English translation was available) where the primary diagnosis of serotonin toxicity (or syndrome) following deliberate self-poisoning and cyproheptadine was administered as the sole serotonergic antagonist. Studies were evaluated for quality and risk of bias. Twelve articles were identified, of which 11 were case reports and one was a case series. Serotonin toxicity was most attributed to selective serotonin reuptake inhibitors and all cases fulfilled Hunter serotonin toxicity criteria. Cyproheptadine regimen varied widely with respect to reporting of initial dose, repeat doses, frequency and duration. Few reports commented on clinical resolution and therefore efficacy was not established. All studies were graded as being of very low evidence and at high risk of bias. There is a lack of evidence to support the efficacy of cyproheptadine or its recommendation in clinical guidelines pertaining to the management of serotonin toxicity.

Toward Personalized Treatment of Depression: An Affordable Citalopram Test based on a Solid-Contact Potentiometric Electrode for at-Home Monitoring of the Antidepressant Dosage

Citalopram (CTLP) is one of the most common antidepressants prescribed worldwide. It has a narrow therapeutic window and can cause severe toxicity and mortality if the dosage exceeds the safe level. Reports indicated that at-home monitoring of citalopram dosage considerably benefits the patients, yet there are no devices capable of such measurement of citalopram in biofluids. This work presents an affordable citalopram test for at-home and point-of-care monitoring of citalopram levels in urine, ensuring a safe and effective drug compliance. Our platform consists of a citalopram-selective yarn-based electrode (CTLP-SYE) that uses polymeric sensing membranes to provide valuable information about drug concentration in urine. CTLP-SYE is noninvasive and has a response time of fewer than 10 s. The fabricated electrode showed near-Nernstian behavior with a 52.3 mV/decade slope in citalopram hydrobromide solutions ranging from 0.5 μM to 1.0 mM, with a detection limit of 0.2 μM. Results also indicated that neither interfering ions nor pH affects electrode performance. We showed that CTLP-SYE could accurately and reproducibly measure citalopram in human urine (RSD 2.0 to 3.2%, error <12%) at clinically relevant concentrations. This work paves the way for the personalized treatment of depression and accessible companion diagnostics to improve treatment efficacy and safety.

Fatal serotonin syndrome: a systematic review of 56 cases in the literature

INTRODUCTION

Serotonin syndrome (SS) is a drug-induced potentially life-threatening clinical condition. There is a paucity of data on the risk factors, clinical course, and complications associated with fatal SS.

OBJECTIVE

To characterize the epidemiological profile, clinical features, and risk factors associated with fatal SS through a systematic review.

METHODS

We performed a systematic review of MEDLINE and Google Scholar for case reports, case series, or cohort studies of fatal SS.

RESULTS

Initial database search identified 2326 articles of which 46 (56 patients) were included in the final analysis. The mean age was 42.3 years (range 18-87 years) with female predominance (57%). North America and Europe constitute 80% of the reported fatal SS. The symptoms evolved very rapidly, within 24 h after the administration of serotonergic drugs in 59% of the cases. Fever (61%) was the most common symptom, followed by seizure (36%) and tremors (30%). The mean temperature in the reported cases (25 patients) was 41.6 ± 1.3 °C (range 38.3-43.5 °C). SS was reported to occur with the maintenance dosage of serotonergic agents, after initiation of the drug for the first time, and addition of the drugs for the development of another unrelated illness. Creatine kinase (CK) activities were elevated (>3 times of the upper limit of normal) in eighteen patients, and it was very high (>25,000 IU/L) in four patients. Presence of high grade fever, seizures, and high CK activities may be associated with severe SS. Nine patients (16%) received 5-HT2A antagonists as a therapy. About 50% of patients died within 24 h of the onset of symptoms.

CONCLUSIONS

While fatal SS is rare, frequently observed features include hyperthermia, seizures, and high CK activities. Cyproheptadine use appears infrequent for these patients.

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.

Citalopram Overdose: a Fatal Case

BACKGROUND

Citalopram is a selective serotonin reuptake inhibitor (SSRI) with cardiac and neurologic toxicities as well as the potential for serotonin syndrome. In most instances, patients recover fully from toxic ingestions of SSRIs. We describe a fatal case of a citalopram overdose.

CASE REPORT

A 35-year-old woman presented to the emergency department after having witnessed seizures at home. An empty citalopram prescription bottle was located, and an intentional overdose was suspected. At the scene, she was found to be in cardiac arrest with pulseless electrical activity and underwent cardiopulmonary resuscitation, including intravenous epinephrine and bicarbonate. In the emergency department, her physical exam was notable for cough and gag reflexes and movement in all extremities with increased muscle tone and tachycardia. Her initial postresuscitation ECG showed sinus rhythm with QRS 92 ms and QTc 502 ms. Her temperature was initially normal, but she rapidly became febrile to 41.8 °C shortly after admission. She was treated symptomatically and with cyproheptadine for suspected serotonin syndrome (SS) but became increasingly hemodynamically unstable over the next 6 h and then developed torsades des pointes (TdP) progressing to pulseless, wide complex tachycardia. She underwent cardiopulmonary resuscitation (CPR) for approximately 50 min but ultimately expired. Postmortem serum analysis revealed a citalopram concentration of 7300 ng/mL (therapeutic range 9-200 ng/mL) and THC, but no other non-resuscitation drugs or substances.

CASE DISCUSSION

Citalopram overdoses often have only mild to moderate symptoms, particularly with ingestions under 600 mg in adults. However, with higher doses, severe manifestations have been described, including QTc prolongation, TdP, and seizures. Serotonin syndrome has also been described in SSRI overdose, and our patient exhibited signs consistent with SS, including increased muscle tone and autonomic dysregulation. Our patient's serum concentration suggests a massive overdose, with major clinical effects, possible SS, and death.

CONCLUSIONS

Although most patients recover from citalopram overdose, high-dose ingestions can produce severe effects and fatalities may occur. In this case, it is likely that the patient's delayed presentation also contributed significantly to her death. The clinician must be aware of the potential for large ingestions of citalopram to produce life-threatening effects and monitor closely for the neurologic, cardiovascular, and other manifestations that, in rare cases, can be fatal.

Serotonin syndrome: is it a reason to avoid the use of tramadol with antidepressants?

BACKGROUND

There is a warning associated with all serotonergic antidepressants and its concomitant use with tramadol due to the concern for a drug-drug interaction resulting in serotonin syndrome (SS). The prescribing of antidepressants with tramadol may be unnecessarily restricted due to fear of causing this syndrome.

OBJECTIVES

There are 3 objectives of this review. To (1) review case reports of SS associated with the combination of tramadol and antidepressant drugs in recommended doses, (2) describe the mechanisms of the drug interaction, and (3) identify the potential risk factors for SS.

METHODS

Case reports of SS associated with tramadol and antidepressants were identified via Cochrane Library, PubMed, and Ovid (through October 2012) using search terms SS, tramadol, antidepressants, fluoxetine, sertraline, paroxetine, fluvoxamine, citalopram, escitalopram, venlafaxine, desvenlafaxine, duloxetine, mirtazapine, milnacipran, trazodone, vilazodone, and bupropion. Cases involving monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants were excluded.

RESULTS

Nine articles were identified describing 10 cases of suspected SS associated with therapeutic doses of tramadol combined with an antidepressant. Mechanisms of the drug-drug interactions involve pharmacodynamic, pharmacokinetic, and possible pharmacogenetic factors.

CONCLUSIONS

Review of the available case reports of tramadol combined with antidepressant drugs in therapeutic doses indicates caution in regard to the potential for SS but does not constitute a contraindication to their use. Tramadol is only contraindicated in combination with MAOIs but not other antidepressants in common use today. These case reports do suggest several factors associated with a greater risk of SS, including increased age, higher dosages, and use of concomitant potent cytochrome P450 2D6 inhibitors. Tramadol can be safely combined with antidepressants; however, monitoring and counseling patients are prudent when starting a new serotonergic agent or when doses are increased.

Recognizing serotonin toxicity in the pediatric emergency department

The use of selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors in treating depression, mood disorders, and behavioral disorders has escalated dramatically in the last 20 years, resulting in increased risk and clinical presentation of serotonin toxicity. Health care providers must also be aware of other medications and substances with proserotonergic activity that can cause serotonin toxicity when used in combination with these medications. There are many adverse effects of selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors, although their toxicity profile compared to older antidepressants seems to be safer. Serotonin syndrome is described as a clinical triad of mental status changes, autonomic hyperactivity, and neuromuscular abnormalities. It encompasses a spectrum of clinical findings ranging from a few nonspecific symptoms to significant clinical toxicity that can result in death. The objectives of this article are to review specific serotonergic medications including their adverse effects and toxicity in overdose, to describe other medications/substances that have proserotonergic effects, which could result in serotonin excess in combination with traditional serotonergic agents, and to define the criteria for serotonin syndrome/toxicity and its treatment.