P. Truedson, Sweden
Presenter of 2 Presentations
EPP0628 - Monoaminoxidase inhibitors as a cause of serotonin syndrome – a systematic case review based on meta-analytic principles
ABSTRACT
Introduction
Serotonin syndrome (SS) is a toxic state characterized by increased serotonin activity. It has been suggested that severe serotonin syndrome usually involves monoaminoxidase inhibitors (MAOIs).
Objectives
To quantify in how far severe SS is associated with MAOIs.
Methods
Systematic review and quantitative analysis of all SS cases published between 1 January 2004 and 31 December 2014. Severe SS was defined as cases, either requiring intensive care or resulting in death. Cases were included if they met the diagnostic criteria for SS according to at least one of the three diagnostic criteria systems (Hunter, Radomski and Sternbach).
Results
Of the 299 included cases, 118 (39%) met the definition for severe SS. Eight cases had insufficient information to enable severity classification. Of the severe cases, 48 (40%) involved a MAOI. Of these, 67% related to psychiatric MAOIs, such as phenelzine and moclobemide and 33% to a somatic MAOI, such as methylene blue and linezolid. Of the remaining 173 non-severe SS cases, 24 cases (13%) involved a MAOI. In these, 12% related to a psychiatric MAOI and 83% to a somatic MAOI. One case (4%) had a combination of both. The odds ratio for MAOI involvement in severe versus non-severe serotonin syndrome was 4.3 (CI 2.4 – 7.5; p < 0.001).
Conclusions
In the majority of published case reports, drugs other than MAOIs are involved in serotonin syndrome, even in severe cases. MAOIs are, however, more common in severe serotonin syndrome than in non-severe cases.
O134 - ECG changes associated with lithium intoxication – a study based on the LISIE project
ABSTRACT
Introduction
It currently remains unclear in how far supratherapeutic lithium serum concentrations can affect the cardiac conduction system. Prolonged QT interval, arrhythmias and cardiac death have all been anecdotally reported, but the systematic studies are few.
Objectives
To examine ECG changes occurring with supratherapeutic lithium concentrations that have given rise to lithium toxicity.
Methods
We examined all episodes of lithium intoxication defined as serum lithium level (≥ 1.5 mmol/L). We analyzed ECG before, during and after intoxication and recorded ECG changes. These, we then assessed according to type of intoxications, clinical and other pharmacological characteristics. The study is based on 20-year data (1997-2020) from the retrospective cohort study (LiSIE) in the Swedish region of Norrbotten.
Results
Of 1101 patients treated with lithium, 77 patients had experienced lithium intoxications. 12 patients had more than one episode of intoxication, yielding 91 episodes. 39 had ECG available both as reference and during lithium intoxication. We found no statistically significant prolongation of the QTc interval during lithium intoxication, compared to respective reference ECG (p = 0.364). Heart rate during lithium intoxication was significantly lower, mean 73 beats/min (SD 16,8, range 43 - 112), compared to the reference ECG, mean 79 beats/min (SD 15,3, range 48-112; p = 0.006). No patient died. All findings were independent of whether an intoxication was acute or chronic.
Conclusions
In our study, heart rate was significantly lower during episodes of intoxication. However, this decrease was of no clinical relevance in most cases. Lithium intoxication was not associated with prolonged QT time.