Lack of significant toxicity after mirtazapine overdose: A five-year review of cases admitted to a regional toxicology unit
ABSTRACT Mirtazapine is a comparatively new antidepressant that selectively blocks central alpha2-adrenergic autoreceptors and postsynaptic 5-HT2 and 5-HT3 receptors, causing reduced neuronal norepinephrine and serotonin reuptake. The prevalence of mirtazapine prescribing has steadily risen; however, comparatively little information is available regarding the clinical features associated with mirtazapine overdose.
To characterize the toxic features that result from mirtazapine overdose.
We performed a retrospective case analysis of patients admitted to the Toxicology Unit of the Royal Infirmary of Edinburgh between January 2000 and December 2004 after stated mirtazapine overdose. Casenotes were examined for clinical, laboratory, and electrocardiographic safety data.
There were 117 mirtazapine cases where the median (interquartile range) stated dose ingested was 450 mg (240-785 mg). Conscious level was reduced in 27.2% of patients and there was a higher incidence of tachycardia (30.4%) than predicted from normal reference range values (p < 0.001). There was no evidence of any other significant clinical, laboratory, or electrocardiographic abnormality.
Severe toxic features could be attributed to other co-ingested drugs or alcohol. The adverse clinical effects attributable to mirtazapine overdose appeared mild and predictable. Mirtazapine overdose appears to be associated with fewer features of severe toxicity than previously reported for other antidepressants.
Full-textDOI: · Available from: W. Stephen Waring, Jun 02, 2015
[Show abstract] [Hide abstract]
ABSTRACT: Newer antidepressants that are more selective in their neurotransmitter effects include the selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and others (agomelatine, bupropion, mirtazapine, reboxetine, vilazodone, vortioxetine). This article systematically reviews data from a variety of sources regarding the potential adverse effects of these medications on various cardiovascular parameters. Potential biochemical mechanisms by which these antidepressants may adversely affect the cardiovascular system are also discussed. Antidepressants that are associated with higher cardiovascular risk (SNRIs, reboxetine), lower risk (SSRIs), and without current evidence of cardiovascular risk (agomelatine, mirtazapine, vilazodone, vortioxetine) are identified. The FDA's recommendations regarding citalopram are organized and summarized, and situations with higher risk of cardiovascular adverse effects are identified.Expert Review of Neurotherapeutics 04/2014; DOI:10.1586/14737175.2014.908709 · 2.83 Impact Factor
Article: MirtazapineCNS Drugs 01/2009; 23(5). DOI:10.2165/00023210-200923050-00006 · 4.38 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: 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.Clinical Toxicology 11/2013; 52(1). DOI:10.3109/15563650.2013.859264 · 3.12 Impact Factor