[Preparedness on Assaults with Highly Toxic Substances in Public Space]. / Vorbereitung auf Anschläge mit hochtoxischen Substanzen im öffentlichen Raum.

The use of chemical substances in terrorist scenarios is to be feared everywhere, especially in the western world, after the events that have become known in recent years. In order to protect civilian populations in an emergency, it is essential that the poisoning pattern (toxidrome) is recognized as quickly and reliably as possible through further training of the relevant agents and the provision of necessary rescue equipment (antidotes) in prepared facilities. In the event of a chemical attack with terrorist motivation, doctors from the Public Health Service (PHS) will foreseeably play a key role in communicating with decision-makers and the public a spart of a competency network.

Mushroom Poisoning.

BACKGROUND: Poisonous mushrooms are eaten by mushroom hunters out of ignorance, after misidentification as edible mushrooms, or as a psychoactive drug. Mushroom poisoning commonly leads to consultation with a poison information center and to hospitalization. METHODS: This review is based on pertinent publications about the syndromes, toxins, and diagnostic modalities that are presented here, which were retrieved by a selective search in PubMed. It is additionally based on the authors' longstanding experience in the diagnosis and treatment of mushroom intoxication, expert consultation in suspected cases, macroscopic identification of wild mushrooms, and analytic techniques. RESULTS: A distinction is usually drawn between mushroom poisoning with a short latency of less than six hours, presenting with a gastrointestinal syndrome whose course is usually relatively harmless, and cases with a longer latency of six to 24 hours or more, whose course can be life-threatening (e.g., phalloides, gyromitra, orellanus, and rhabdomyolysis syndrome). The DRG diagnosis data for Germany over the period 2000-2018 include a total of 4412 hospitalizations and 22 deaths due to the toxic effects of mushroom consumption. 90% of the fatalities were due to the death cap mushroom (amatoxins). Gastrointestinal syndromes due to mushroom consumption can be caused not only by poisonous mushrooms, but also by the eating of microbially spoiled, raw, or inadequately cooked mushrooms, or by excessively copious or frequent mushroom consumption. CONCLUSION: There are few analytic techniques available other than the qualitative demonstration of amatoxins. Thus, the diagnosis is generally made on the basis of the clinical manifestations and their latency, along with meticulous history-taking, assisted by a mushroom expert, about the type(s) of mushroom that were consumed and the manner of their preparation.

Mushroom poisoning: A proposed new clinical classification.

Mushroom poisoning is a significant and increasing form of toxin-induced-disease. Existing classifications of mushroom poisoning do not include more recently described new syndromes of mushroom poisoning and this can impede the diagnostic process. We reviewed the literature on mushroom poisoning, concentrating on the period since the current major classification published in 1994, to identify all new syndromes of poisoning and organise them into a new integrated classification, supported by a new diagnostic algorithm. New syndromes were eligible for inclusion if there was sufficient detail about both causation and clinical descriptions. Criteria included: identity of mushrooms, clinical profile, epidemiology, and the distinctive features of poisoning in comparison with previously documented syndromes. We propose 6 major groups based on key clinical features relevant in distinguishing between poisoning syndromes. Some clinical features, notably gastrointestinal symptoms, are common to many mushroom poisoning syndromes. Group 1 - Cytotoxic mushroom poisoning. Syndromes with specific major internal organ pathology: (Subgroup 1.1; Primary hepatotoxicity); 1A, primary hepatotoxicity (amatoxins); (Subgroup 1.2; Primary nephrotoxicity); 1B, early primary nephrotoxicity (amino hexadienoic acid; AHDA); 1C, delayed primary nephrotoxicity (orellanines). Group 2 - Neurotoxic mushroom poisoning. Syndromes with primary neurotoxicity: 2A, hallucinogenic mushrooms (psilocybins and related toxins); 2B, autonomic-toxicity mushrooms (muscarines); 2C, CNS-toxicity mushrooms (ibotenic acid/muscimol); 2D, morel neurologic syndrome (Morchella spp.). Group 3 - Myotoxic mushroom poisoning. Syndromes with rhabdomyolysis as the primary feature: 3A, rapid onset (Russula spp.); 3B, delayed onset (Tricholoma spp.). Group 4 - Metabolic, endocrine and related toxicity mushroom poisoning. Syndromes with a variety of clinical presentations affecting metabolic and/or endocrine processes: 4A, GABA-blocking mushroom poisoning (gyromitrins); 4B, disulfiram-like (coprines); 4C, polyporic mushroom poisoning (polyporic acid); 4D, trichothecene mushroom poisoning (Podostroma spp.); 4E, hypoglycaemic mushroom poisoning (Trogia venenata); 4F, hyperprocalcitoninemia mushroom poisoning (Boletus satanas); 4G, pancytopenic mushroom poisoning (Ganoderma neojaponicum). Group 5 - Gastrointestinal irritant mushroom poisoning. This group includes a wide variety of mushrooms that cause gastrointestinal effects without causing other clinically significant effects. Group 6 - Miscellaneous adverse reactions to mushrooms. Syndromes which do not fit within the previous 5 groups: 6A, Shiitake mushroom dermatitis; 6B, erythromelagic mushrooms (Clitocybe acromelagia); 6C, Paxillus syndrome (Paxillus involutus); 6D, encephalopathy syndrome (Pleurocybella porrigens).

Psychiatric comorbidity and personality structure in patients with polyvalent addiction.

BACKGROUND: This study focuses on the systematic psychiatric evaluation of polydrug-using opiate-dependent patients, using the standard DSM-IV diagnostic interviews and a new psychodynamic instrument operationalizing personality organization (Structured Interview of Personality Organization, STIPO). SAMPLING AND METHOD: 50 patients were interviewed with the Structured Clinical Interview for DSM-IV Disorders (SCID) I and II and the STIPO by two independent researchers at a detoxification treatment unit. RESULTS: According to the SCID I and II, all patients had at least one axis I disorder, 90% at least one axis II disorder. A correspondence was found between STIPO and SCID results, in that more pathology in the SCID coincided with more severity in the STIPO. According to the STIPO, 100% of the patients were located at the level of borderline personality organization, indicating identity pathology according to Kernberg's model. CONCLUSION: Given the fact that comorbid psychiatric disorders compromise the outcome of detoxification and dehabituation treatments, it is highly relevant to diagnose these disorders and to assess underlying personality pathology. While the evidence of psychosocial treatments in addiction therapy is still weak, the integration of syndrome-tailored treatment modules may help improve the treatment of patients with this chronically relapsing condition. LIMITATION: small sample size.

Organophosphate poisoning in the developed world - a single centre experience from here to the millennium.

Organophosphate (OP) poisoning is still associated with high morbidity and mortality rates, both in resource-poor settings and in well-developed countries. Despite numerous publications dealing with this particular poison, detailed clinical data on more severe overdoses with these agents are relatively sparsely reported. A retrospective study was consequently conducted on 33 patients with OP poisoning admitted to our intensive care unit (ICU) to provide additional data on clinical features. We included moderate to severe poisonings between 2000 and 2012 who required admission to ICU. Patients ingested dimethyl-OPs in 19 cases, diethyl-OPs in 8 cases and otherwise classified OPs in 6 cases. Death (5/33) occurred rather late and only one of these fatalities died during on-going cholinergic crisis. Of the survivors (28/33), 71% recovered fully while 29% showed predominantly neurological disabilities before being transferred to neurologic rehabilitation. Aspiration pneumonia predominated in 27/33 patients and one patient died in refractory acute respiratory distress syndrome (ARDS). The intermediate syndrome occurred twice and cardiopulmonary resuscitation had to be performed in 6/33 patients. Fatalities showed a higher Poison-severity-score, APACHE-II-score and SOFA-score on admission compared with survivors and they showed significantly longer QTc-time in the ECG, lower systolic blood pressure and heart rate, a lower pH and a lower base excess on admission. Patients with diethyl-OPs required intubation significantly earlier and showed lower and more sustained inhibited activity of the plasma-cholinesterase on admission compared with patients ingesting dimethyl-OPs. Treatment with atropine and obidoxime was comparable between these groups and severity of poisoning, outcome, hemodynamics on admission, duration of mechanical ventilation and length of stay in the ICU did not significantly differ between the involved group of dimethyl- and diethyl-OPs. We conclude that the fatality rate in our patient cohort treated in a well-staffed and equipped ICU of a developed country is quite similarly high compared with the rate observed in developing countries. Patients died rather late when severe cholinergic crisis had mostly been overcome and death was therefore related to non-poison specific complications.

Intravenous application of an anticalin dramatically lowers plasma digoxin levels and reduces its toxic effects in rats.

Lipocalins tailored with high affinity for prescribed ligands, so-called anticalins, constitute promising candidates as antidotes. Here, we present an animal study to investigate both pharmacokinetic and clinical effects of an anticalin specific for the digitalis compound digoxin. Intravenous digoxin (2.5-50 µg/kg/min) was administered to rats until first changes in the ECG occurred (dose finding study) or a priori for 30 min (kinetic study). The anticalin DigA16(H86N), dubbed DigiCal, was administered intravenously at absolute doses of 1, 5, 10 and 20 mg, while the control group received isotonic saline. Hemodynamic changes, several ECG parameters and digoxin concentration in plasma were monitored at given time intervals. After DigiCal administration free digoxin concentration in plasma ultrafiltrate declined dramatically within 1 min to the presumably non-toxic range. There was also a significant and DigiCal dose-dependent effect on longer survival, less ECG alterations, arrhythmia, and improved hemodynamics. Infusion of a lower digoxin dose (2.5 µg/kg/min) resulted in a more sustained reduction of free digoxin in plasma after DigiCal administration compared to a higher digoxin dose (25 µg/kg/min), whereas ECG and hemodynamic parameters did not markedly differ, reflecting the known relative insensitivity of rats towards digoxin toxicity. Notably, we observed a re-increase of free digoxin in plasma some time after bolus administration of DigiCal, which was presumably due to toxin redistribution from tissue in combination with the relatively fast renal clearance of the rather small protein antidote. We conclude that anticalins with appropriately engineered drug-binding activities and, possibly, prolonged plasma half-life offer prospects for next-generation antidotal therapy.

Clinical and analytical features of severe suicidal quetiapine overdoses--a retrospective cohort study.

CONTEXT: Detailed data on severe overdoses with quetiapine are relatively sparsely reported in the literature. OBJECTIVE: To describe a cohort of 20 acute quetiapine overdoses and provide additional data on the pharmacokinetics and clinical features of intoxication with this drug. MATERIAL AND METHODS: A retrospective study was conducted on patients with quetiapine poisoning admitted to our institution. We included moderate to severe overdoses between 2005-2011 who required admission to ICU. RESULTS: Predominantly female patients (n = 17) ingested a median dose of 9.8 g quetiapine. Poison Severity Score was moderate in 9 patients, severe in 10 patients and in one case fatal. Quetiapine was analytically confirmed in all cases. Clinical manifestations included drowsiness or coma (all patients), tachycardia (12 patients) and hypotension (10 patients). Seizures and arrhythmia occurred in 4 patients, each. Intubation and mechanical ventilation was required in 14 patients due to seizures, respiratory depression or loss of airway protection and 15 patients developed pneumonia. Hypokalaemia and hyperglycaemia were present at admission in 10 and 5 patients, respectively. Despite frequent prolongation of the QT(c) in 13 patients, QT interval was normal in most cases and QRS-interval was prolonged in only one patient. Presumably anticholinergic delirium was recognised in 8 patients and 6 patients received physostigmine with good clinical response. In 13 cases quetiapine was analysed quantitatively in serum with a relevantly prolonged half-life (16 ± 12 h) and a median peak serum concentration of 3074 ng/mL. In 4 of these 13 patients we observed an increase of quetiapine serum concentration in the further course. CONCLUSION: In this study, quetiapine overdoses were associated with significant toxicity and a fairly high number of complications. A careful and often prolonged clinical observation in the more severe cases of overdose seems mandatory.

Atropine maintenance dosage in patients with severe organophosphate pesticide poisoning.

Although the importance of atropine in therapy of organophosphate (OP) poisoning is generally recognized, its dosing is a matter of debate. A retrospective analysis of atropine dosing was undertaken in 34 patients who had been enrolled in a clinical study assessing obidoxime effectiveness in OP-poisoning. All patients were severely intoxicated (suicidal attempts) and required artificial ventilation. Atropine was administered routinely by intensive care physicians for life-threatening muscarinic symptoms, with the recommendation to favor low dosage. The pharmacological active enantiomere S-hyoscyamine was determined by a radioreceptor assay. When RBC-AChE activity ranged between 10% and 30%, S-hyoscyamine plasma concentrations of approx. 5 nmol L⁻¹ were sufficient. This concentration could be maintained with about 0.005 mg h⁻¹ kg⁻¹ atropine. Only when RBC-AChE was completely inhibited, therapy of cholinergic crisis required atropine doses up to 0.06 mg h⁻¹ kg⁻¹. Elimination half-life of S-hyoscyamine was 1.5 h, showing occasionally a second slow elimination phase with t(½)=12 h. Malignant arrhythmias were observed in some 10% of our cases, which occurred late and often in the absence of relevant glandular cholinergic signs, when the S-hyoscyamine concentration was below 2.5 nmol L⁻¹. Arrhythmias mostly resolved on reinstitution of atropine.

Risk assessment of moderate to severe alcohol withdrawal--predictors for seizures and delirium tremens in the course of withdrawal.

AIMS: To develop a prediction model for withdrawal seizures (WS) and delirium tremens (DT) during moderate to severe alcohol withdrawal syndrome (AWS) in a large cohort of inpatients treated for AWS (n = 827). METHODS: Re-analysis of a cohort study population treated between 2000 and 2009. All patients received a score-guided and symptom-triggered therapy for AWS. Multivariable binary logistic regression models with stepwise variable selection procedures were conducted providing odds ratio (OR) estimates. RESULTS: In the multivariable regression, significant predictors of WS during AWS therapy were a delayed climax of withdrawal severity since admission [OR/10 h: 1.23; 95% confidence interval (CI): 1.1-1.4; P < 0.001)], prevalence of structural brain lesions in the patient's history (OR 6.5; 95% CI: 3.0-14.1; P < 0.001) and WS as the cause of admittance (OR 2.6; 95% CI: 1.4-4.8; P = 0.002). Significant predictors at admission for the occurrence of DT were lower serum potassium (OR/1 mmol/l 0.33; 95% CI: 0.17-0.65; P = 0.001), a lower platelet count (OR/100.000 0.42; 95% CI: 0.26-0.69; P = 0.001) and prevalence of structural brain lesions (OR 5.8; 95% CI: 2.6-12.9; P < 0.001). CONCLUSION: In this large retrospective cohort, some easily determinable parameters at admission may be useful to predict a complicated course of alcohol withdrawal regarding the occurrence of WS or DT. Using the provided nomograms, clinicians can estimate the percentage likelihood of patients to develop either WS or DT during their course of withdrawal. Prevalence of structural brain lesions in the patient's history does strongly warrant a careful observation of patients.

Case series: Alcohol intolerance with Coprine-like syndrome after consumption of the mushroom Lepiota aspera (Pers.:Fr.) Quél., 1886 (Freckled Dapperling).

Alcohol intolerance after consumption of wild mushrooms is a recognized phenomenon. This is best understood with Coprinus atramentarius. Its active component Coprine blocks enzymatic ethanol degradation at the stage of acetaldehyde, which is responsible for the well-recognized symptoms. Here, we report three events in five patients experiencing the same symptoms after consumption of self-collected Lepiota aspera. All had mistaken L. aspera for edible mushrooms as Amanita rubescens or Macrolepiota procera. In all events, L. aspera was identified by mycologists and no other mushrooms were involved. The mushrooms were well sautéed and tolerated well until an alcoholic beverage was consumed. Then within few minutes facial flushing, throbbing headache, tachycardia, and shortness of breath all occurred. The symptoms abated within a few hours with no sequelae but could be re-provoked by further alcohol consumption up to 48 h later. This syndrome appears to be identical with the one known from C. atramentarius. However, the toxin in L. aspera or its mechanism is not yet known.

Carbamazepine and valproate as adjuncts in the treatment of alcohol withdrawal syndrome: a retrospective cohort study.

AIMS: To compare the clinical course, incidence of withdrawal seizures (WS) or delirium tremens (DT) and side effects during treatment of alcohol withdrawal in patients treated with either carbamazepine (CBZ) or valproate (VPA) as an adjunct to clomethiazole and clonidine therapy. METHODS: Retrospective analysis of charts of two cohorts of inpatients treated during 2000-2009: CBZ 374 patients, VPA 453 patients. RESULTS: At baseline, those treated with VPA and those treated with CBZ were similar except for a trend to younger age and a higher incidence of previous WS in the CBZ group. The median duration of pharmacological treatment (91 vs. 76 h; P < 0.001) and the length of stay (8 vs. 6 days; P < 0.001) as well as the need for intensive care treatment (7 vs. 2%; P = 0.001) were significantly higher in the CBZ than the VPA group. Additionally, withdrawal-related complications such as WS occurred more often in the CBZ group (9.6 vs. 5.5%; not significant after adjusting for potential confounders); the incidence of DT in the CBZ group was insignificantly higher (6.6 vs. 4.4%; P = 0.52). Admittance with seizures and older age were predictors of WS and DT, respectively. Adverse drug reactions, mainly affecting the central nervous system, were significantly more frequent with CBZ than VPA (7.6 vs. 2%; P < 0.001). CONCLUSION: During alcohol withdrawal, VPA may offer some benefits compared with CBZ due to favorable tolerability, possibly less incidence of WS and a shorter duration of pharmacological treatment.

High-performance liquid-chromatographic tandem-mass spectrometric methods for atropinesterase-mediated enantioselective and chiral determination of R- and S-hyoscyamine in plasma.

S-hyoscyamine (S-hyo) is a toxic tropane alkaloid from plants of the solanacea family, which is extracted for pharmaceutical purposes thereby undergoing racemization (atropine). Merely the S-hyo enantiomer acts as an antagonist of muscarinic receptors (MR). Nevertheless, racemic atropine is clinically administered in e.g. ophthalmology and for symptomatic therapy of acute poisoning with organophosphorus compounds (OPCs, e.g. pesticides, nerve agents). However, very limited data are available of comparative pharmacokinetics of S- and R-enantiomers in humans or other species. Therefore, we developed an enantioselective LC-ESI-MS/MS assay making use of rabbit serum containing atropinesterase (AtrE, EC 3.1.1.10) which is suitable for stereospecific hydrolysis of S-hyo into tropine and tropic acid while R-hyo is unaffected. For sample preparation plasma was incubated with human serum (not containing AtrE, procedure A) and with rabbit serum (procedure B). Afterwards, hyoscyamines were quantified by a validated previously published non-chiral LC-ESI-MS/MS method. Following procedure A the concentration of total hyo and following procedure B remaining R-hyo were determined. S-hyo was calculated by the difference between these concentrations. This assay design allowed reproducible, precise (RSD 2-9%), accurate (93-101%) and selective determination of total and individual hyoscyamines. Potential therapeutics for OPC poisoning (carbamates, oximes) and thiono-pesticides did not interfere with the assay whereas some oxon-pesticides inhibited S-hyo hydrolysis. A control experiment was designed allowing to be aware of such interferences thus avoiding the use of false results. To validate this assay, results were compared to those from a novel isocratic chiral LC-ESI-MS/MS method. Separation of S-hyo (t(R) 31.1 ± 0.2 min) and R-hyo (t(R) 33.4 ± 0.2 min) was achieved on α-glycoprotein (AGP) chiral stationary phase at 40°C (selectivity factor α 1.07). Ammoniumformate (0.01 M, pH 8.0) with 3.75% (v/v) acetonitrile served as mobile phase (300 µL min(-1)). Hyoscyamines were detected in the positive multiple reaction monitor mode. The enantioselective assay was applied to the analysis of atropine degradation in diluted rabbit serum in vitro as well as to human in vivo plasma samples from a pesticide-poisoned patient treated with atropine.

Predictors of treatment outcomes after removal of amalgam fillings: associations between subjective symptoms, psychometric variables and mercury levels.

OBJECTIVE: This analysis aimed to study predictors of different treatment outcomes and associations between subjective symptoms, psychometric variables and mercury levels in patients who subjectively attributed their health problems to dental amalgam. MATERIAL AND METHODS: A secondary and retrospective analysis of data of a recently published randomized clinical trial was performed. Seventy-eight patients [44% female, mean (SD) age 35 (6) years, randomly assigned to either amalgam removal or a health promotion program] were included into statistical analysis. Prior to intervention and 12 months later, questionnaires for assessing symptoms, psychological distress and health status were presented, and mercury levels in blood and urine were determined. RESULTS: The patients' personality profile at study onset was characterized by slightly reduced extraversion and slightly elevated emotional instability. Overall, subjective symptoms decreased slightly and there were no statistically significant differences in the decrease of symptoms after intervention between both groups. Decrease of mercury levels after intervention was closely associated with removal of amalgam fillings (r(mult) = 0.64 in regression analysis). Statistically significant correlations could be found between mercury levels and subjective symptoms with respect to baseline (r = 0.29-0.39) and to changes after intervention (r = 0.24-0.42), but not for psychological distress (r = 0.05-0.25) and health related quality of life (r = -0.03-0.18). Prediction of symptom improvement after intervention was poor (r(mult) = 0.44). CONCLUSIONS: Results contribute some new aspects to the inconsistent findings in the literature with respect to associations between symptoms and subtoxic mercury levels. More emphasis should be placed on exploring individual vulnerability for amalgam sensitivity.

Free and total digoxin in serum during treatment of acute digoxin poisoning with Fab fragments: case study.

A woman ingested 10 mg of methyldigoxin in a suicide attempt and presented 19 hours after ingestion with clinical signs of glycoside intoxication. Her serum level of digoxin was 7.4 ng/mL, and antidotal therapy with Fab antibody fragments was started. The manufacturer's recommended dosing scheme was modified, with 80 mg Fab administered intravenously within 15 minutes followed by a continuous infusion at 30 mg/h. Total serum concentration of digoxin increased markedly within minutes after Fab therapy was started, while the level of free digoxin immediately decreased into the nontoxic range without recrudescent toxic effects of digoxin. The cumulative amounts of free and bound digoxin that were excreted in urine within 30 hours after ingestion were 900 microg and 1600 microg, respectively. Half-life of bound digoxin in urine was 9.9 hours; mean rate of clearance of bound digoxin in the urine was 7.0 mL/min. On the basis of these kinetic data, a smaller initial bolus dose of Fab followed by a continuous infusion may be a more tailored, cost-effective, and relatively safe therapy for patients who have overdosed on cardiac glycosides.

Assessment of neuromuscular dysfunction during poisoning by organophosphorus compounds.

Dysfunction of respiratory muscles is a life-threatening complication in poisoning by organophosphorus compounds (OPs). It is both of central and peripheral origin due to impaired cholinergic signalling upon inhibition of acetylcholinesterase (AChE). The dysfunction at neuromuscular synapses is not amenable to anticholinergics and remains a therapeutic challenge. Thus, a clear understanding of the distinct mechanisms occurring at neuromuscular synapses is decisive for the development and improvement of therapeutic strategies, particularly with nerve agent poisoning, where clinical studies are prevented by ethical considerations. Using red blood cell AChE, the kinetics of OP induced inhibition, aging, and spontaneous and oxime-induced reactivation have been elucidated. In a dynamically working in vitro model with real-time determination of membrane-bound AChE, it was shown that the kinetic constants derived from erythrocyte AChE are comparable to muscle AChE in a given species. To assess, whether kinetic considerations of AChE activity are relevant for the neuromuscular function, organotypic spinal cord-skeletal muscle cocultures have been established. In this model neostigmine and VX affected neuromuscular transmission as anticipated from their known actions on AChE. Also oxime-induced restoration of the neuromuscular transmission was observed. These findings were confirmed by functional studies on diaphragm muscles of various species with determination of muscle force generation upon phrenic nerve or indirect electrical field stimulation techniques. Investigations with human intercostal muscles are in progress to assess the conditions in human tissue. The results obtained with paraoxon favourably correlate with data from clinical findings of parathion-poisoned patients where the correlation of neuromuscular transmission with the activity of erythrocyte AChE could be established. In conclusion, a variety of methods are available to follow the microscopic reactions occurring at the synaptic level. Due to the lack of clinical data with different OPs, e.g. nerve agents, well designed animal experiments, reflecting the human situation as close as possible, are indispensable for the development of new drugs against the deleterious OP effects.

Obidoxime in acute organophosphate poisoning: 1 - clinical effectiveness.

OBJECTIVE: The effects of obidoxime in the treatment of organophosphate poisoning were assessed by comparing the clinical course with its effects on laboratory parameters relevant to poisoning. In this article we report clinical findings and activity of cholinesterase in plasma and acetylcholinesterase (AChE) in red blood cells. In a linked paper we describe changes in neuromuscular transmission and atropine concentrations in the same patient cohort. METHODS: We studied 34 atropinized patients with severe parathion, oxydemeton methyl, and dimethoate self-poisoning who were treated with obidoxime in a standard protocol. We measured the AChE activity in blood and related it to clinical features of organophosphate poisoning. RESULTS: Patients poisoned with parathion responded promptly to obidoxime (250 mg bolus followed by continuous infusion at 750 mg/day up to 1 week) with improvement of neuromuscular transmission and increased AChE activity. The effects were only transient in cases with the other poisons. Death (7/34) occurred late and was mostly due to complications rather than due to ongoing cholinergic crisis. CONCLUSIONS: Obidoxime appeared safe and reactivated AChE in parathion poisoning.

Obidoxime in acute organophosphate poisoning: 2 - PK/PD relationships.

OBJECTIVE: The effects of obidoxime in the treatment of organophosphate poisoning were assessed by biochemical and biological effect monitoring. In this article we report effects on neuromuscular function, oxime and atropine concentration, and relate them to acetylcholinesterase (AChE) activity. METHODS: We measured the activity of cholinesterase in plasma and AChE in red blood cells (RBC) and related these data with neuromuscular transmission analysis (ulnar nerve stimulation). Concomitantly, poison and oxon along with plasma obidoxime and atropine levels were measured at regular intervals. RESULTS: We found a close correlation between RBC-AChE activity and neuromuscular transmission and a reciprocal correlation between both the atropine maintenance dose and/or its plasma concentration. The steady state of RBC-AChE activity of reactivation and re-inhibition followed the course predicted by laboratory-determined reaction constants. CONCLUSIONS: Intense monitoring of organophosphate-poisoned patients allowed assessment of why a given obidoxime concentration was, or was not, able to counteract the re-inhibition of the RBC-AChE. RBC-AChE activity mirrors the function of n-receptor- and m-receptor-mediated cholinergic signaling as measured by neuromuscular transmission and atropine requirements.

Risk assessment of severe tricyclic antidepressant overdose.

Prognostic factors for severe complications in tricyclic antidepressant (TCA) overdose remain unclear. We therefore evaluated the value of clinical characteristics and electrocardiograph (ECG) parameters to predict serious events (seizures, arrhythmia, death) in severe TCA overdose of 100 patients using logistic regression models for risk assessment. The overall fatality rate was 6%, arrhythmia occurred in 21% and 31% of the patients developed seizures. Using an univariable logistic regression model, the maximal QRS interval (OR 1.22; 95% CI 1.06-1.41; p = .005), the time lag between ingestion and occurrence of first symptoms of overdose (OR 1.13; 95% CI 0.99-1.29; p = .072) and the age (OR 0.73; 95% CI 0.55-0.98; p = .038) were determined as the solely predictive parameters. In the multivariable logistic regression model, the QRS interval could not be established as independent predictor, however, the terminal 40-ms frontal plane QRS vector (T40) reached statistical significance regarding prediction of serious events (odds ration [OR] 1.70; 95% confidence interval [CI] 1.02-2.84; p = .041), along with age and time lag between ingestion and onset of symptoms of overdose with a sensitivity and specificity of 71% and 70%, respectively. Evaluation of both clinical characteristics and ECG-parameters in the early stage of TCA overdose may help to identify those patients who urgently need further aggressive medical observation and management.