Acute mycophenolate overdose: case series and systematic literature analysis

BACKGROUND

Literature regarding acute human toxicity of mycophenolate mofetil (MMF) and enteric-coated mycophenolate sodium (EC-MPS) is limited.

OBJECTIVES

Our objectives were to describe all cases of overdose with MMF or EC-MPS reported to the Swiss Toxicological Information Centre (STIC) or in the literature between 1995 and 2013. Therefore, we performed an observational case-series and systematic literature search to determine circumstances, magnitude, management and outcome of overdose with MMF or EC-MPS.

RESULTS

Of 152,762 reports to STIC, 15 (7 pediatric) involved overdose with MMF (n = 13) or EC-MPS (n = 2). Three cases from other centers were identified from a systematic literature search. The magnitude of overdose ranged from 1.2 to 16.7 (median 2.9) times usual dose. Six (33%) MMF overdoses had attributable symptoms, which included abdominal pain, vomiting, headache and dizziness. The majority of findings were minor, although a 9-fold MMF overdose caused hypotension 8 h after ingestion and a 12.5-fold overdose caused leukopenia after 5 days. Symptoms did not occur in patients who took 2.5 times or less of their usual MMF dose. Gastrointestinal decontamination measures with activated charcoal were undertaken in one-third of cases.

CONCLUSIONS

Acute MMF and EC-MPS overdoses had a favorable outcome in all cases reported to STIC and in the literature.

Acute thiopurine overdose: analysis of reports to a National Poison Centre 1995-2013

Literature regarding acute human toxicity of thiopurines is limited to a handful of case reports. Our objectives were to describe all cases of overdose with thiopurines reported to the Swiss Toxicological Information Centre between 1995–2013. A retrospective analysis was performed to determine circumstances, magnitude, management and outcome of overdose with these substances. A total of 40 cases (14 paediatric) were reported (azathioprine, n = 35; 6-mercaptopurine, n = 5). Of these, 25 were with suicidal intent, 12 were accidental and 3 were iatrogenic errors. The magnitude of overdose ranged from 1.5 to 43 (median 8) times the usual dose in adults. Twelve cases (30%) had attributable symptoms. The majority of these were minor and included gastrointestinal complaints and liver function test and blood count abnormalities. Symptoms were experienced by patients who took at least 1.5-times their usual daily thiopurine dose. Overdoses over two or more consecutive days, even if of modest size, were less well tolerated. One case of azathioprine and allopurinol co-ingestion over consecutive days led to agranulocytosis. Decontamination measures were undertaken in 11 cases (10 activated charcoal, 1 gastric lavage) and these developed fewer symptoms than untreated patients. This study shows that acute overdoses with thiopurines have a favourable outcome in the majority of cases and provides preliminary evidence that gastrointestinal decontamination with activated charcoal may reduce symptom development after overdose of these substances if patients present to medical services soon after ingestion.

Acute calcineurin inhibitor overdose: analysis of cases reported to a national poison center between 1995 and 2011

Transplant recipients and other patients requiring immunosuppression with calcineurin inhibitors or their household contacts may be exposed to overdose. This study investigated the circumstances, pharmacokinetics and outcomes of overdose with cyclosporine and tacrolimus reported to the Swiss Toxicological Information Centre between 1995 and 2011. Of 145,396 reports by healthcare professionals, 28 (0.02%) concerned enteral or parenteral overdose with these calcineurin inhibitors. Thirteen (46%) were iatrogenic errors, 12 (43%) were with suicidal intent and 3 (11%) were accidental. Iatrogenic overdoses usually involved noncapsule drug formulations. Acute enteral overdoses caused symptoms in a dose-dependent fashion but were generally well tolerated; the mean multiple of patient's usual dose was 20.8 ± 28.8 for symptomatic versus 4.4 ± 3.4 for asymptomatic cases (p = 0.037). The most common symptoms were nausea, headache, somnolence, confusion, hypertension and renal impairment. In contrast, acute intravenous overdoses were often poorly tolerated and resulted in one fatality due to cerebral edema after a cyclosporine overdose. Enteral decontamination measures were performed in six cases involving oral ingestion and appeared to reduce drug absorption, as shown by pharmacokinetic calculations. In the one case where it was used, pharmacoenhancement appeared to accelerate tacrolimus clearance after intravenous overdose.

Medication wrong route administration: a poisons center-based study

OBJECTIVES

To describe clinical effects, circumstances of occurrence, management and outcomes of cases of inadvertent administration of medications by an incorrect parenteral route.

METHODS

Retrospective single-center consecutive review of parenteral route errors of medications, reported to our center between January 2006 and June 2010. We collected demographic data and information on medications, route and time of administration, severity of symptoms/signs, treatment, and outcome.

RESULTS

Seventy-eight cases (68 adults, 10 children) were available for analysis. The following wrong administration routes were recorded: paravenous (51%), intravenous (33%), subcutaneous (8%), and others (8%). Medications most frequently involved were iodinated x-ray contrast media (11%) and iron infusions (9%). Twenty-eight percent of the patients were asymptomatic and 54% showed mild symptoms; moderate and severe symptoms were observed in 9% and 7.7%, respectively, and were mostly due to intravenous administration errors. There was no fatal outcome. In most symptomatic cases local nonspecific treatment was performed.

CONCLUSIONS

Enquiries concerning administration of medicines by an incorrect parenteral route were rare, and mainly involved iodinated x-ray contrast media and iron infusions. Most events occurred in adults and showed a benign clinical course. Although the majority of exposures concerned the paravenous route, the occasional severe cases were observed mainly after inadvertent intravenous administration.

Mushroom poisoning: a study on circumstances of exposure and patterns of toxicity

BACKGROUND

Picking wild mushrooms is a popular pastime in Switzerland. Correct identification of the species is difficult for laypersons. Ingestion of toxic mushrooms may result in serious toxicity, including death. The aim of the study is to analyze and describe the circumstances of exposure to mushrooms, and to define the clinical relevance of mushroom poisoning for humans in Central Europe.

MATERIALS AND METHODS

We performed a retrospective case study and analyzed all inquiries concerning human exposures to mushrooms (n = 5638, 1.2% of all inquiries) which were reported to the Swiss Toxicological Information Centre between January 1995 and December 2009.

RESULTS

The most frequent reason for contacting the poison center in cases of adult exposure was toxicity resulting from edible species. Pediatric exposure predominantly occurred from mushrooms found around the home. Severe symptoms have not only been observed after ingestion of non-amatoxin-containing toxic mushrooms, i.e. Boletus sp. and Cortinarius sp., but also after meals of edible species. The mortality of confirmed amatoxin poisonings was high (5/32) compared to other reports.

CONCLUSIONS

Inquiries regarding mushroom poisoning were a relatively infrequent reason for contacting the poison center. Nevertheless, accidental ingestion of toxic mushrooms can be responsible for severe or fatal poisonings. Although pediatric exposure to mushrooms found around the home has not led to serious toxicity in this study, prevention of exposure is warranted. Inspection of wild mushrooms by a certified mushroom expert or a mycologist seems to be a safe procedure which should be recommended.

Patterns of toxicity and factors influencing severity in acute adult trimipramine poisoning

AIMS

To analyze the clinical features of trimipramine poisoning, identify a minimal toxic dose, and the dose bearing a 50% risk of developing a moderate, severe or fatal outcome.

METHODS

All acute adult trimipramine monointoxications reported by physicians to the Swiss Toxicological Information Centre between January 1992 and December 2009 were identified.

RESULTS

Two hundred and thirty cases (26 confirmed and 204 probable) were analyzed, the mean age was 35.7 years and 74% were females. One hundred and thirty-seven patients showed mild, 54 moderate and 21 severe symptoms. Three cases were fatal due to refractory cardiovascular collapse. Ninety-three per cent of the events were attempted or completed suicides. The most common symptoms were central nervous system depression (79.2%), tachycardia (19.1%) and QT(c) prolongation (13.9%). The severity of poisoning depended significantly on the ingested dose (P < 0.001). The minimal dose for moderate symptoms was 250 mg (median dose 1.2 g) and 850 mg for severe symptoms (median dose 2.7 g). The dose for a 50% risk of developing a moderate, severe or fatal outcome was 5.11 g. In 38 patients early gastrointestinal decontamination was performed. Overall, these patients ingested higher trimipramine doses than the late- or not-decontaminated patients (P = 0.113). The median doses were also higher in the decontaminated group within each severity category except in the fatal cases.

CONCLUSIONS

We demonstrated that moderate trimipramine poisoning can already occur after ingestion of doses in the high therapeutic range. Poisoned patients have to be monitored for central nervous system depression, dysrhythmias and QT(c) prolongation. Early decontamination might be beneficial.

Countering health threats by chemicals with a potential terrorist background--creating a rapid alert system for Europe

BACKGROUND

The acronym "ASHT" stands for "Alerting System and Development of a Health Surveillance System for the Deliberate Release of Chemicals by Terrorists". Imagine this scenario: 15 patients with respiratory symptoms following a concert in Rome and 12 patients coughing after lunch in a cafeteria in the Czech Republic; are these events related? Today these events would never be connected as there is no mechanism to allow EU Member States to share this type of information effectively. The main objective of the ASHT project was to improve data sharing between EU Member States. In part, this was achieved by an internet accessible EU-wide alerting system with the aim to detect the deliberate (i.e. criminal or terrorist) or accidental release of chemicals. Nevertheless more information from police, fire brigades and health professionals is needed.

METHODS

Description of the design, development, functionality and testing of the relational database system called "RAS-CHEM" (Rapid Alert System for Chemicals).

RESULTS

A database structure appropriate for the description of "events" with sophisticated retrieval functions was developed. For evaluation purposes 37 events were entered into the database including 29 scenarios and 8 historical mass intoxications. The alert level was "background information" for 21 events, "suspected mass intoxication" for 6 cases and "confirmed mass intoxication" for 10 events.

CONCLUSION

The RAS-CHEM database works and will be integrated into the Health Emergency Operations Facility (HEOF) with other European Rapid Alert Systems. Poisons centres receive a large number of enquiries and could be important sentinels in this field of toxicovigilance.

Acute plant poisoning: analysis of clinical features and circumstances of exposure

INTRODUCTION

Human contact with potentially toxic plants, which may occur through abuse or by accident or attempted suicide, is frequent and sometimes results in clinically significant toxicity.

OBJECTIVE

The aim of the present study was to identify which plants may lead to severe poisoning, and to define the clinical relevance of plant toxicity for humans in Switzerland.

METHODS

We analyzed 42,193 cases of human plant exposure and 255 acute moderate, severe, and lethal poisonings, which were reported to the Swiss Toxicological Information Centre between January 1995 and December 2009.

RESULTS

Plant contact was rarely responsible for serious poisonings. Lethal intoxications were extremely rare and were caused by plants with cardiotoxic (Taxus baccata) or mitosis-inhibiting (Colchicum autumnale) properties.

CONCLUSIONS

Most often, plant contact was accidental and patients remained asymptomatic or developed mild symptoms, which fully resolved within a short time.

Retrospective analysis of stimulant abuse cases reported to the Swiss Toxicological Information Centre during 1997-2009

STUDY AIM

To describe characteristics of stimulant abuse and toxicity.

METHOD

We conducted a retrospective analysis of cases of exposure to cocaine, amphetamines (amphetamine, methamphetamine, and 3,4-methylenedioxymethamphetamine [MDMA]) and methylphenidate reported to the Swiss Toxicological Information Centre between 1997 and 2009.

RESULTS

There were 667 reports for cocaine, 147 for amphetamine, 41 for methamphetamine, 433 for MDMA, and 122 for methylphenidate. Detailed outcome data were available in 546 (39%) of all reported cases. Exposure to amphetamine or MDMA commonly resulted in mild to moderate toxicity, but severe toxicity was seen in approximately 15% of reported cocaine and MDMA exposures with a known medical outcome. Frequently observed clinical signs and symptoms included tachycardia, arterial hypertension, nausea, agitation, and panic. Amphetamine and MDMA exposures were seen in a younger population and were mainly reported at weekends, while cocaine users were older and exposures occurred proportionally more frequently on weekdays. Parenteral drug use and co-use of heroin was more frequent in cocaine users than in those using other stimulants. There has been an increase in reports of non-medical use of methylphenidate in recent years, indicating a need for further studies of abuse of prescription stimulants.

CONCLUSION

Stimulant abuse is associated with major toxicity in approximately 15% of reported cases with a known medical outcome. Amphetamine and MDMA users differed from cocaine users in terms of user characteristics, time of use and medical complications. Non-medical use of prescription stimulants such as methylphenidate needs attention.

The value of acute toxicity studies to support the clinical management of overdose and poisoning: a cross-discipline consensus

Acute toxicity studies are no longer required to support first clinical trials of pharmaceuticals in man. However, it is unclear in the wording of the revised ICH M3 whether acute toxicity studies are required later in drug development (e.g., phase 3) in order to support the management of overdose. The NC3Rs held a workshop in January 2010 with representatives from international poison centres, the pharmaceutical and chemical industries, and regulatory and government bodies to explore further whether acute toxicity studies are used to support the clinical management of overdose of pharmaceuticals and whether this work can be translated to other sectors such as the chemical industry. The consensus formed at the workshop was that acute toxicity studies are not used for managing overdose of pharmaceuticals and are of little value in treating human poisoning from chemicals. In this paper, the authors describe the key considerations in treating human overdose and poisoning, challenge the value of the classification and labelling process of chemicals for this purpose and discuss how acute toxicity studies can be improved to better inform risk assessment.

Escitalopram causes fewer seizures in human overdose than citalopram

CONTEXT

Seizures are a recognized complication of acute overdose with the racemic (1:1 ratio of R- and S-enantiomers) selective serotonin reuptake inhibitor antidepressant citalopram.

OBJECTIVE

We tested the hypothesis that escitalopram (the therapeutically active S-enantiomer of citalopram) causes fewer seizures in overdose than citalopram at comparable doses of the S-enantiomer.

METHODS

Multicenter retrospective review of cases with citalopram and escitalopram overdose reported to German, Austrian, and Swiss Poisons Centers between 1997 and 2006.

RESULTS

316 citalopram and 63 escitalopram cases were analyzed. Somnolence, nausea, vomiting, tachycardia, QT prolongation, and tremor occurred with similar frequency in both groups. There was a striking difference in the frequency of single and multiple seizures: 43 cases (13.5%) in the citalopram group and 1 case (1.6%) with a single seizure in the escitalopram group (p=0.0065).

DISCUSSION AND CONCLUSIONS

At comparable ingested doses of the S-enantiomer, the symptom profile for citalopram and escitalopram intoxications is similar except for seizures that occur more frequently in citalopram than in escitalopram poisoning.

A Fatal Case of Autumn Crocus (Colchicum Autumnale) Poisoning in a Heifer: Confirmation by Mass-Spectrometric Colchicine Detection

A heifer developed severe signs of acute gastrointestinal irritation 48 hr after ingesting fresh leaves of Colchicum autumnale growing on a damp meadow. Confirmation of the suspected toxicosis was obtained by detecting colchicine in serum and urine using liquid chromatography coupled with tandem mass spectrometry using atmospheric pressure chemical ionization. Although the serum colchicine concentration had declined to an apparently nontoxic level of 2.4 ng/ml, a more prominent concentration (640 ng/ml) indicative of colchicine poisoning was detected in the urine. This finding is consistent with the known toxicokinetic properties of colchicine, whereby a large volume of distribution results in low circulating blood concentrations and prolonged urinary excretion.

Household chemicals: management of intoxication and antidotes

Exposure to household products is very common, but in industrialized countries severe or fatal poisoning with household products is rare today, due to the legal restriction of sale of hazardous household products. The big challenge for physicians, pharmacologists and toxicologists is to identify the few exceptional life-threatening situations where immediate intervention is needed. Among thousands of innocuous products available for the household only very few are hazardous. Substances found in these products include detergents, corrosives, alcohols, hydrocarbons, and some of the essential oils. The ingestion of batteries and magnets and the exposure to cyanoacrylates (super glue) can cause complications in exceptional situations. Among the most dangerous substances still present in household products are ethylene glycol and methanol. These substances cause major toxicity only through their metabolites. Therefore, initial symptoms may be only mild or absent. Treatment even in asymptomatic patients has to be initiated as early as possible to inhibit production of toxic metabolites. For all substances not only the compound itself but also the route of exposure is relevant for toxicity. Oral ingestion and inhalation generally lead to most pronounced symptoms, while dermal exposure is often limited to mild irritation. However, certain circumstances need special attention. Exposure to hydrofluoric acid may lead to fatal hypocalcemia, depending on the concentration, duration of exposure, and area of the affected skin. Accidents with hydrocarbon pressure injectors and spray guns are very serious events, which may lead to amputation of affected limbs. Button batteries normally pass the gastrointestinal tract without problems even in toddlers; in rare cases, however, they get lodged in the esophagus with the risk of localized tissue damage and esophageal perforation.