Mirtazapine overdose is unlikely to cause major toxicity

Figures & data

Fig. 1. The number of cases presenting each year separated into isolated and co-ingestant groups.

Table 1. Characteristics of mirtazapine overdose patients, divided into isolated ingestion of tablets with or without alcohol and co-ingestant groups.

	Total group (N = 267)
Characteristics	Mirtazapine (± Alcohol) (N = 89)	Mirtazapine and at least one other ingestant (N = 178)
Age, y (IQR)	36 (26–49)	36.5 (26–46)
Sex, female (%)	45 (51%)	116 (65%)
Median dose ingested, mg (IQR)	420 (270–750)	300 (240–600)
Clinical findings:
Minimum GCS < 15	41 (46%)	82 (54%)
Minimum GCS < 9	0	26 (15%)
ICU admission	0	29 (16%)
Seizure	0	0
Serotonin Toxicity	0	2 (1%)
Delirium	0	9 (5%)
Abnormal QT	0	21 (13%)*
Maximum HR > 99 bpm	29 (33%)	99 (56%)
Minimum HR < 61 bpm	9 (10%)	19 (11%)
Maximum BP > 140 mmHg	32 (36%)	16 (9%)
Minimum BP < 90 mmHg	2 (2%)	64 (40%)

*162 presentations had an ECG.

Fig. 2. Scatter plot of the doses for different GCS. The two outliers with large ingestions with a GCS of 15 presented greater than 15 h after their ingestion.

Fig. 3. A plot of the QT vs HR on the QT Nomogram for mirtazapine only ingestions (filled circles) (A) and mirtazapine with co-ingestants (open squares) (B).