Journal of toxicology. Clinical toxicology最新文献

Objective: To compare the toxicity of citalopram, venlafaxine, mirtazapine, and nefazadone after overdose.

Methods: Two-year retrospective review of consecutive patients admitted to the toxicology unit of Edinburgh Royal Infirmary. Outcome measure included physiological variables, ECG recordings, peak creatine kinase, development of arrhythmias, seizure, tremor or agitation, and the need for admission to a critical care facility.

Results: A total of 225 patients were studied. Venlafaxine was associated with a significantly higher pulse rate (p < 0.0001) and tremor (p = 0.007) than other antidepressants. Citalopram was associated with a significantly longer QT interval on ECG recording (p < 0.0001) but mean QTc durations were not significantly different between all drugs studied. No arrhythmias were recorded. Only venlafaxine and citalopram caused seizures and were associated with the need for admission to Intensive Care, but there was no significant difference between them.

Conclusions: Mirtazapine and nefazadone appear safe in overdose and were associated with minimal features of neurological or cardiovascular toxicity. Citalopram is more likely to cause QT prolongation but other features of cardiovascular toxicity were uncommon. Both citalopram and venlafaxine are proconvulsants. Venlafaxine also causes more frequent features of the serotonin syndrome.

Flumazenil is frequently administered to the poisoned patient. Seizures may be precipitated and resedation may occur in patients who awakened following flumazenil administration. Seizures may increase morbidity and mortality of the overdose. Benefit:Risk ratio of administering flumazenil should be determined in each overdose patient. Indications for flumazenil are limited.

Background: Dipyrone is a pyrazolone derivative used as an analgesic and antipyretic. Agranulocytosis, dipyrone's most serious and potentially fatal adverse effect, has led to its withdrawal in several countries. However, agranulocytosis is subject to geographical variability, ratio with at risks ranging from 0.8-23.7. In many countries dipyrone is still widely used in adults and children and even as an over-the-counter (OTC) preparation. Information on the effects of dipyrone overdose is scanty.

Objective: To determine the demographic and clinical characteristics of dipyrone overdose.

Methods: Retrospective review of prospectively collected poison center data on acute exposure to dipyrone over a three-year period. The data were subjected to descriptive analysis. Mann-Whitney test and Chi-square analysis were performed where relevant.

Results: A total of 243 records met the inclusion and exclusion criteria. Median age was 17y (4m-83y), median amount 5 g (250 mg-45 g), and median time to consultation was 2 h (5 min-48 h). Toxic events (49) occurred in 39 (16%) patients; 57% of these were gastrointestinal and all were mild. Time to consultation was longer in the symptomatic patients (4 h vs. 1.5 h, respectively, p=0.001) and in children (8 h vs. 3.5 h in adults). Suicidal patients ingested significantly larger amounts (8 g vs. 3.7 g, respectively, p=0.001), as did patients with gastrointestinal symptomatology (7.5 g vs. 5 g in asymptomatics, p=0.001). No agranulocytosis was reported.

Discussion: Dipyrone overdose is associated with mild, mainly gastrointestinal toxicity; this was noted at a median dose of 7.5 g. Early gastrointestinal decontamination may have prevented toxicity. The suggested treatment includes gastrointestinal decontamination (if <1 h since ingestion) and supportive measures.