Exotic venomous snakebites in Switzerland reported to the National Poisons Information Centre over 22 years

OBJECTIVE

The private keeping of exotic venomous snakes is legally permitted in Switzerland. The aim of the present study was to characterise the epidemiological and clinical features of bites by exotic venomous snakes over a period of 22 years in Switzerland.

METHODS

We included all calls related to exotic snakebites recorded at the Swiss National Poisons Information Centre (Tox Info Suisse) from 1997 to 2018. Exclusion criteria comprised indigenous snakes, non-venomous exotic snakes such boas or pythons, clinical courses incompatible with a snakebite or calls from abroad. Follow-up information was graded according to the Poisoning Severity Score.

RESULTS

Within the study period, 1,364 calls related to snakebites were recorded at Tox Info Suisse; 148 (11%) cases were attributed to exotic venomous snakes and fulfilled the study criteria. A total of 112 (98%) of 114 patients with medical follow-up information exhibited sufficient causality between exposure and clinical effects. Only adult patients were affected. The median age was 40 years (range 16-71) and the male gender was predominant (n = 136, 92%). Viperidae were involved in 87 (78%) and Elapidae in 25 (22%) patients. Overall, the main affected body part was the hand (89 patients, 79%). In the majority of the patients the clinical course was mild (46, 41%) or moderate (40, 36%), in a lower proportion asymptomatic (6, 5%) or with severe symptoms (20, 18%). No fatalities were reported in the study period. Severe symptoms were observed after elapid bites in six patients (24%) and after viper bites in 14 patients (16%). Besides local effects, neurological disorders after elapid bites and haematological disorders after viper bites were most frequently reported. Antivenom was administered in 24% (27 patients: 18 Viperidae, 21% and 9 Elapidae, 36%; 5 patients (4%) required multiple doses), overall, with good resolution of symptoms.

CONCLUSION

Exotic snakebite is a rare occurrence in Switzerland but has led to medically relevant morbidity, sometimes requiring antivenom treatment. Over half of the envenomed patients required symptomatic or specific treatment. No fatalities or bites in children were reported.

Observational cross-sectional case study of toxicities of antifungal drugs

INTRODUCTION

In this study we examined the toxicities, including poisoning and overdoses, with polyene, azole, flucytosine and echinocandin antifungals reported to the National Poison Center.

METHODS

An observational cross-sectional study on antifungals was performed based on reports between 1995 and 2016 to Tox Info Suisse. Patient demographic and clinical characteristics were summarized among all reported calls, stratified by age group. In secondary analyses, we evaluated cases with clinical follow-up information.

RESULTS

In total, 149 cases were reported to the National Poison Centre within the study period of which 49 (32.9%) were male and 91 (61.1%) were female. 95 (63.8%) were adults and 54 (36.2%) were children (age ≤ 16). The most frequently reported drug class were the azoles (n=136, 91.3%). In 31 cases (21%) reported by the treating physicians, further clinical follow-up information was available. Nearly half of these patients were asymptomatic (n=15, 48%). Among those with symptoms, in 11 (33%) patients, the symptoms of toxicity were categorized with a strong causality to the respective antifungal. Clinical findings caused by the triazoles were effects in the gastrointestinal tract, hallucinations and predilirium state. The clinical findings caused by the polyenes were mostly minor symptoms with infusion-related effects or hypokalemia. In 6 (54.6%) out of 11 cases the severity was categorized as minor and for 5 (45.5%) as moderate, respectively.

CONCLUSION

Despite high administered doses, no severe or fatal cases occurred within the study period. Although various toxicities can occur with antifungal administration and overdoses, they showed a favorable safety profile.

Indigenous venomous snakebites in Switzerland: analysis of reports to the National Poisons Information Centre over 22 years

INTRODUCTION

Two venomous snakes, the asp viper (Vipera aspis) and the common adder (Vipera berus) are native to Switzerland. Bites by both vipers cause mainly local effects, but systemic envenomation is possible.

METHODS

We analysed all calls concerning indigenous venomous snakebites recorded at the Swiss National Poisons Information Centre between 1997 and 2018, including all cases with identification by a herpetologist, and/or with compatible symptoms and circumstances of the exposure.

RESULTS

During the study period, 1,364 cases concerned snakebites. One third (466; 34%) were attributed to indigenous vipers. In 243 (52%) patients, medical follow-up information was available, with good causality between exposure and symptoms in 219 (90%) patients. Vipera aspis was identified in 77 of the cases (35%), Vipera berus in 54 (25%), and not further specified vipers in 88 (40%). In over two thirds of the 219 cases (155, 71%) adult patients were affected (male 109, female 46; median age 43 years [range 16-90]). Sixty-four patients were children (male 47, female 16; median age 11 years [range 1.3-15.9]). The highest occurrence of bites was in the summer months. In the majority of patients, the clinical course was mild (94; 43%) or moderate (80; 36%); a lower proportion was either asymptomatic (17; 8%) or exhibited severe symptoms (28; 13%). There were no fatalities reported. The most frequent symptoms were local effects at the bite site with mild (100; 46%) to moderate (56; 25%) swelling, pain (65; 30%) and redness (51; 23%). Gastrointestinal symptoms including nausea (31; 14%), vomiting (47; 22%) and abdominal pain (25; 11%) were also common. Other systemic symptoms included cardiovascular effects (e.g., hypotension (20; 9%) or shock [6; 3%]), neurotoxicity (e.g., visual impairment [5; 2.3%]) and haematotoxicity (e.g., coagulopathy [11; 5%]). Seven (3.2%) patients developed anaphylactic reactions. Antivenom was administered in only 20% (24 with moderate and 19 with severe symptoms) with good resolution of symptoms. The mean duration of hospitalization was 2 days (0-12 days).

CONCLUSION

Snakebites in Switzerland can result in severe symptoms, sometimes necessitating antivenom treatment.

Coadministration of tizanidine and ciprofloxacin: a retrospective analysis of the WHO pharmacovigilance database

PURPOSE

Tizanidine, an alpha-adrenergic substance with antinociceptive and antihypertensive effects, is extensively metabolized via cytochrome P450 (CYP) 1A2. Therefore, coadministration with potent CYP1A2 inhibitors, such as ciprofloxacin, is contraindicated. However, both drugs are broadly utilized in various countries. Their concomitant use bears an inherent high risk for clinically significant symptoms, especially in multimorbid patients experiencing polypharmacy. This study aims to investigate the impact of coadministration of tizanidine and ciprofloxacin using real-world pharmacovigilance data and to raise awareness of this potentially underestimated safety issue.

METHODS

We conducted a retrospective study including Individual Case Safety Reports (ICSR) registered until March 1, 2017, in the World Health Organization (WHO) global database. Demographic data, drug administration information, the course of the adverse drug reaction (ADR), its severity, and outcomes were analyzed for cases reporting ciprofloxacin comedication.

RESULTS

In 91 (2.0%) of the identified 4192 worldwide ICSR on tizanidine, coadministration of ciprofloxacin was reported. Most of the patients were female (n = 59, 64.8%) with a median age of 54 years (range 13-85 years). The countries contributing most reports were the USA (n = 54, 59.3%) and Switzerland (n = 16, 17.6%). ADRs reported most often affected the nervous system and the cardiac function, especially with large tizanidine doses or drugs with CNS and cardiovascular depressant effects. In two cases, a fatal outcome was reported.

CONCLUSION

Despite the existing formal contraindication, the concomitant use of tizanidine and ciprofloxacin can be observed in real-world clinical practice. Reactions mainly affected the central nervous and the cardiovascular system resulting in potentially severe adverse effects. The concomitant use of tizanidine and ciprofloxacin should absolutely be avoided.

Extracorporeal life support as bridge to recovery in yew poisoning: case reports and literature review

Aims

This short communication aims to review the treatment of cardiogenic shock in patients with yew poisoning based on two case reports from our institution, focusing on the use of extracorporeal life support (ECLS).

Methods and results

We report two cases of Taxus baccata poisoning treated with ECLS at our institution and review the literature based on a search in PubMed and Google Scholar on the topic of yew poisoning and ECLS. All cases were combined for analysis of demographics, ECLS therapy, and outcome. Case 1: A 35‐year‐old woman developed polymorphic ventricular tachycardia followed by cardiovascular arrest 5 h after orally ingesting a handful of yew needles. Successful resuscitation required ECLS for 72 h due to ongoing cardiac arrhythmias and cardiogenic shock. The patient left the hospital without neurological sequelae after 10 days. Case 2: A 30‐year‐old woman developed refractory cardiac arrhythmias and circulatory arrest. Resuscitation included ECLS for 71 h. T. baccata needles found by gastroscopy confirmed the diagnosis. The patient had no neurologic deficits and was transferred to psychiatry after 11 days. Review of the literature: Nine case reports were found and analysed along with our two cases. Five out of the 11 (45%) patients were female. Median (range) age was 28 (19–46) years. T. baccata needles were ingested with a suicidal intention in all patients. Median (range) duration of ECLS was 70 h (24–120 h). Eight (73%) patients had full neurological recovery.

Conclusions

Yew poisoning is a differential diagnosis in young psychiatric patients presenting with polymorphic ventricular tachycardia and cardiogenic shock. A characteristic cardiac contraction pattern in echocardiography may present a diagnostic clue. The early use of ECLS is a valuable bridge to recovery in most of these patients.

National Poison Center Calls Before vs After Availability of High-Dose Acetaminophen (Paracetamol) Tablets in Switzerland

IMPORTANCE

Acetaminophen (paracetamol) is among the most widely used pain medications worldwide; while safe within the therapeutic range, intake exceeding 4000 mg/d can lead to hepatotoxicity. Prior evidence suggests that limiting the availability of large quantities of acetaminophen is associated with decreased acetaminophen-related poisonings and mortality; in Switzerland, 500-mg tablets are available over-the-counter (OTC) and, as of October 2003, 1000-mg tablets are available with prescription.

OBJECTIVE

To evaluate the association of adding 1000-mg acetaminophen tablets to the Swiss market with utilization and poisonings.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used a quasi-experimental interrupted time series analysis to evaluate 15 790 acetaminophen poison records from January 1, 2000, to December 31, 2018. All calls for acetaminophen-related poisonings identified from the National Swiss Poisons Centre and all sales for oral acetaminophen tablets (prescription and OTC) dispensed between January 2000 and December 2018 were included.

EXPOSURE

October 3, 2003 (Q4 2003), was defined as the intervention date, corresponding to the date of market entry for 1000-mg acetaminophen tablets in Switzerland.

MAIN OUTCOMES AND MEASURES

The primary outcome was the number of quarterly acetaminophen-related poison calls to the National Poison Centre. Additional outcomes included quarterly sales for acetaminophen and change in poisoning circumstances, stratified by preintervention and postintervention periods and by formulation (ie, 500-mg and 1000-mg tablets).

RESULTS

Between 2000 and 2018, 15 790 acetaminophen-related poisoning calls were identified, of which 10 628 (67.3%) were regarding women, and the mean (SD) age of patients was 25.2 (18.2) years. The interrupted time series analysis identified a significant increase in the slope for the number of reported poisonings following the intervention point, particularly for accidental circumstances (z score, -3.62; P < .001). In the preintervention period, 120 of 961 poisonings (15.3%) involved a dose greater than 10 000 mg, while for the postintervention period, 1140 of 5696 (30.6%) had a dose larger than 10 000 mg (P < .001). There was a rapid uptake in 1000-mg acetaminophen sales, while sales of the 500-mg tablet decreased slightly. Since 2012, a mean (SD) of 20.7 million (1.4 million) 1000-mg tablets were dispensed quarterly compared with 2.7 million (0.5 million) 500-mg tablets.

CONCLUSIONS AND RELEVANCE

This study found a significant increase in acetaminophen dispensing and acetaminophen-related poisonings in Switzerland following the approval of 1000-mg tablets in 2003. The availability of 1000-mg acetaminophen should be re-evaluated to minimize the potential for accidental poisonings.

Characteristics of emergency department presentations requiring consultation of the national Poisons Information Centre

AIMS OF THE STUDY

To describe the characteristics of cases presenting at the emergency department due to (suspected) poisoning for which consultation on patient management with the national Poisons Information Centre was required.

METHODS

Retrospective study at the emergency department of Bern University Hospital, Switzerland, from May 2012 to December 2017. Cases were identified in the electronic patient database using appropriate full-text search terms. Cases were excluded if the contact with the National Poisons Information Centre was through an external hospital or directly by the patient. Cases in which the poison centre was not contacted and cases without the patient&rsquo;s general consent to use their medical data for research purposes were also excluded.

RESULTS

Overall, 667 cases from the study period were included. The median age was 32 years (range 16&ndash;94); 405 patients (61%) were female and 262 (39%) male. In most cases, the poisoning was acute (n = 631, 95%) and intentional (n = 505, 76%). The most common route of exposure was ingestion (n = 587, 88%) and the most commonly involved substances were sedatives (n = 185, 28%), antidepressants (n = 162, 24%) and non-opioid analgesics (n = 161, 24%). Impaired consciousness was documented in 299 cases (45%). Approximately half of the cases (n = 359, 54%) were of minor severity as assessed using the Poisoning Severity Score, 142 (21%) were of moderate severity, 110 (16%) were asymptomatic and 56 (8%) were severe. There were no fatalities. In most cases (n = 599, 90%), immediate therapeutic or diagnostic measures were undertaken prior to contact with the poison centre. Decontamination measures and specific antidotes undertaken or administered only after contacting the poison centre included whole bowel irrigation, haemodialysis, fomepizole, biperiden, silibinin, deferoxamine, leucovorin, dimercaptopropanesulfonic acid and hydroxocobalamin. Administration of a specific antidote/therapeutic agent was recommended in 87 cases (13%). In 70 of these 87 cases (80%), the specific agents were administered as recommended by the poison centre. In 17 cases (20%), the specific antidotes were not administered as recommended because of either clinical improvement (n = 11), termination of therapy based on laboratory results (n = 3), therapy refused by the patient (n = 2), or identification of a mushroom as non-poisonous (n = 1). In 109 cases (16%), there was no change in patient management after contacting the poison centre.

CONCLUSIONS

For patients presenting at the emergency department with severe poisoning, contact with the poison information centre can help to implement specific treatment and avoid fatalities. In less severe cases involving more common agents (e.g. paracetamol, benzodiazepines), contact can help to avoid unnecessary treatment and serve as a source of information and/or confirmation.

Risk of Seizures Associated with Antidepressant Use in Patients with Depressive Disorder: Follow-up Study with a Nested Case-Control Analysis Using the Clinical Practice Research Datalink

INTRODUCTION

Antidepressant use has been associated with an increased risk of seizures. Evidence on the association between antidepressant use at therapeutic doses and seizures mainly comes from clinical trials that were not designed to investigate this potential relationship.

OBJECTIVE

The objective of this study was to assess the risk of first-time seizures in association with exposure to antidepressants in patients with depressive disorders.

METHODS

We conducted a retrospective follow-up study with a nested case-control analysis between 1998 and 2012, using data from the UK-based Clinical Practice Research Datalink (CPRD). We estimated crude incidence rates with 95 % confidence intervals (CIs) of seizures in depressed patients who used selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), 'other antidepressants', no antidepressants, or who had used antidepressants in the past. To adjust for potential confounding, we estimated odds ratios of antidepressant drug use among cases with seizures and matched controls in a nested case-control analysis.

RESULTS

Of 151,005 depressed patients, 619 had an incident seizure during follow-up. Incidence rates per 10,000 person-years were 12.44 (95 % CI 10.67-14.21) in SSRI users, 15.44 (95 % CI 8.99-21.89) in SNRI users, 8.33 (95 % CI 4.68-11.98) in TCA users, 9.33 (95 % CI 6.19-12.46) in non-users of antidepressants, and 5.05 (95 % CI 4.49-5.62) in past users of antidepressants. In the case-control analysis, relative risk estimates for seizures were increased in current users of SSRIs (adjusted odds ratio 1.98, 95 % CI 1.48-2.66) and SNRIs (adjusted odds ratio 1.99, 95 % CI 1.20-3.29), but not TCAs (adjusted odds ratio 0.99, 95 % CI 0.63-1.53), compared with non-users.

CONCLUSION

Current use of SSRIs or SNRIs was associated with a twofold increased risk of first-time seizures compared with non-use, while current use of TCAs (mostly low dose) was not associated with seizures. Treatment initiation in SSRI and SNRI users was associated with a higher risk of seizures than longer-term treatment.

Introducing Mushroom Fruiting Patterns from the Swiss National Poisons Information Centre

Changes in the ecology of macrofungi are poorly understood, not only because much of their life cycle is hidden belowground, but also because experiments often miss real-world complexity and most fruitbody inventories are limited in space and time. The National Poisons Information Centre ‘Tox Info Suisse’ provides countrywide 24hours/7days medical advice in case of poisonings since 1966. Here, we introduce a total of 12,126 mushroom-related phone calls that were received by Tox Info Suisse between 1966 and 2014. This indirect source of mycological information is dominated by the families of Boletaceae (11%), Agaricaceae (10%) and Amanitaceae (8%), which account for ~30% of all cases. Mushroom fruiting patterns revealed by the Poisons Centre inventory statistically resemble changes in fungal phenology, productivity and diversity as reflected by the Swiss National Data Centre ‘SwissFungi’. Although the newly developed Tox Info Suisse dataset provides an innovative basis for timely environmental research, caution is advised when interpreting some of the observed long-term changes and autumnal extremes. Uncertainty of the new record relates to possible data incompleteness, imprecise species description and/or identification, as well as the inclusion of cultivated and non-indigenous mushrooms. Nevertheless, we hope that the Tox Info Suisse inventory will stimulate and enable a variety of ecological-oriented follow-up studies.

[Bites of venomous snakes in Switzerland]

Although snake bites are rare in Europe, there are a constant number of snake bites in Switzerland. There are two domestic venomous snakes in Switzerland: the aspic viper (Vipera aspis) and the common European adder (Vipera berus). Bites from venomous snakes are caused either by one of the two domestic venomous snakes or by an exotic venomous snake kept in a terrarium. Snake- bites can cause both a local and/or a systemic envenoming. Potentially fatal systemic complications are related to disturbances of the hemostatic- and cardiovascular system as well as the central or peripheral nervous system. Beside a symptomatic therapy the administration of antivenom is the only causal therapy to neutralize the venomous toxins.

Acute Toxicity Associated With the Recreational Use of the Novel Psychoactive Benzofuran N-methyl-5-(2 aminopropyl)benzofuran

N-methyl-5-(2 aminopropyl)benzofuran (5-MAPB) is a novel psychoactive benzofuran, created by N-methylation of 5-(2-aminopropyl)benzofuran (5-APB), which shares structural features with methylenedioxymethamphetamine (MDMA). To our knowledge, no case of 5-MAPB-related toxicity has been published in the scientific literature. We report a case of oral 5-MAPB exposure confirmed by liquid chromatography-tandem mass spectrometry in a 24-year-old previously healthy white man. Observed symptoms and signs such as paleness, cold and clammy skin, hypertension, elevated high-sensitive troponin T level, tachycardia, ECG change, diaphoresis, mild hyperthermia, mydriasis, tremor, hyperreflexia, clonus, agitation, disorientation, hallucinations, convulsions, reduced level of consciousness, and creatine kinase level elevation (305 IU/L) were compatible with undesired effects related to 5-APB or MDMA exposure. Signs and symptoms resolved substantially within 14 hours with aggressive symptomatic treatment, including sedation with benzodiazepines, external cooling, analgesia and sedation with fentanyl-propofol, and treatment with urapidil, an α-receptor-blocking agent. 5-MAPB showed first-order elimination kinetics with a half-life of 6.5 hours, comparable to the half-life of MDMA. According to the chemical structure, this case report, and users' Web reports, 5-MAPB appears to have an acute toxicity profile similar to that of 5-APB and MDMA, with marked vasoconstrictor effect.

Adverse Effects of Plant Food Supplements and Plants Consumed as Food: Results from the Poisons Centres-Based PlantLIBRA Study

Plant food supplements (PFS) are products of increasing popularity and wide-spread distribution. Nevertheless, information about their risks is limited. To fill this gap, a poisons centres-based study was performed as part of the EU project PlantLIBRA. Multicentre retrospective review of data from selected European and Brazilian poisons centres, involving human cases of adverse effects due to plants consumed as food or as ingredients of food supplements recorded between 2006 and 2010. Ten poisons centres provided a total of 75 cases. In 57 cases (76%) a PFS was involved; in 18 (24%) a plant was ingested as food. The 10 most frequently reported plants were Valeriana officinalis, Camellia sinensis, Paullinia cupana, Melissa officinalis, Passiflora incarnata, Mentha piperita, Glycyrrhiza glabra, Ilex paraguariensis, Panax ginseng, and Citrus aurantium. The most frequently observed clinical effects were neurotoxicity and gastro-intestinal symptoms. Most cases showed a benign clinical course; however, five cases were severe. PFS-related adverse effects seem to be relatively infrequent issues for poisons centres. Most cases showed mild symptoms. Nevertheless, the occurrence of some severe adverse effects and the increasing popularity of PFS require continuous active surveillance, and further research is warranted. Copyright © 2016 John Wiley & Sons, Ltd.

Adverse effects of plant food supplements and botanical preparations: a systematic review with critical evaluation of causality

AIMS

The objective of this review was to collect available data on the following: (i) adverse effects observed in humans from the intake of plant food supplements or botanical preparations; (ii) the misidentification of poisonous plants; and (iii) interactions between plant food supplements/botanicals and conventional drugs or nutrients.

METHODS

PubMed/MEDLINE and Embase were searched from database inception to June 2014, using the terms 'adverse effect/s', 'poisoning/s', 'plant food supplement/s', 'misidentification/s' and 'interaction/s' in combination with the relevant plant name. All papers were critically evaluated according to the World Health Organization Guidelines for causality assessment.

RESULTS

Data were obtained for 66 plants that are common ingredients of plant food supplements; of the 492 papers selected, 402 (81.7%) dealt with adverse effects directly associated with the botanical and 89 (18.1%) concerned interactions with conventional drugs. Only one case was associated with misidentification. Adverse effects were reported for 39 of the 66 botanical substances searched. Of the total references, 86.6% were associated with 14 plants, including Glycine max/soybean (19.3%), Glycyrrhiza glabra/liquorice (12.2%), Camellia sinensis/green tea ( 8.7%) and Ginkgo biloba/gingko (8.5%).

CONCLUSIONS

Considering the length of time examined and the number of plants included in the review, it is remarkable that: (i) the adverse effects due to botanical ingredients were relatively infrequent, if assessed for causality; and (ii) the number of severe clinical reactions was very limited, but some fatal cases have been described. Data presented in this review were assessed for quality in order to make the results maximally useful for clinicians in identifying or excluding deleterious effects of botanicals.

Incidence and causative agents of chemical eye injuries in Switzerland

CONTEXT

Chemical eye injuries are ophthalmological emergencies with a high risk of secondary complications and severe visual loss. Only limited epidemiological data for such injuries are available for many countries.

PATIENTS AND METHODS

We performed two independent studies. The cause of chemical eye injuries was assessed with a prospective questionnaire study. Questionnaires were sent to all ophthalmologists in Switzerland. A total of 163 patients (205 eyes) were included, between December 2012 and October 2014. Independent of the questionnaire study, the incidence of chemical eye injuries was assessed with a retrospective cohort study design using the database of the mandatory accident insurance.

RESULTS

Ophthalmological questionnaires revealed that plaster/cement (20.5%), alkaline (12.2%) and acid (10.2%) solutions caused the highest number of chemical injuries. Only 2% of all injuries were classified as grade III and none as grade IV (Roper-Hall classification). The official toxicological information phone-hotline was contacted in 4.3% of cases. Using data from the accident insurance, an incidence of chemical eye injuries of about 50/100 000/year was found in the working population.

CONCLUSION

Here, we present data on the involved agents of chemical eye injuries in Switzerland, and also the incidence of such injuries in the working population. This may also help to assess the need for further education programs and to improve and direct preventive measures.

[Nalmefene and Opioid Withdrawal Syndrome: Analysis of the Global Pharmacovigilance Database for Adverse Drug Reactions]

Nalmefene (Selincro®) is a selective opioid receptor antagonist, licensed in April 2014 in Switzerland for the reduction of alcohol consumption in adults with a high drinking risk level. 200 reports of adverse drug reactions of nalmefene have been documented worldwide in the WHO global pharmacovigilance database between 7th March 1997 to 1st March 2015. In 21 cases (10,5%) nalmefene and an opioid were administered concomitantly, causing withdrawal symptoms. Until now, the regional pharmacovigilance center in Zurich received four cases of nalmefene combined with opioids. This combination should be avoided.

Acute sirolimus overdose: a multicenter case series

BACKGROUND

There are few data relating to sirolimus overdose in the medical literature. Our objectives were to describe all cases of overdose with sirolimus reported to Swiss, German and Austrian Poisons Centres between 2002-2013.

METHODS

An observational case-series analysis was performed to determine circumstances, magnitude, management and outcome of sirolimus overdose.

RESULTS

Five cases of acute sirolimus overdose were reported--three in young children and two in adults. Four were accidental and one was with suicidal intent. Two patients developed symptoms probably related to sirolimus overdose: mild elevation of alkaline phosphatase, fever and gastroenteritis in a 2.5-year-old male who ingested 3 mg, and mild changes in total cholesterol in an 18-year-old female after ingestion of 103 mg. None of these events were life-threatening. Serial blood concentration measurements were performed starting 24 h after ingestion of 103 mg in a single case, and these followed a similar pharmacokinetic time-course to measurements taken after dosing in the therapeutic range.

CONCLUSIONS

Acute sirolimus overdose occurred accidentally in the majority of cases. Even large overdoses appeared to be well-tolerated, however children might be at greater risk of developing complications. Further study of sirolimus overdose is needed.

Acute toxicity profile of tolperisone in overdose: Observational poison centre-based study

INTRODUCTION

Tolperisone is a centrally acting muscle relaxant that acts by blocking voltage-gated sodium and calcium channels. There is a lack of information on the clinical features of tolperisone poisoning in the literature. The aim of this study was to investigate the demographics, circumstances and clinical features of acute overdoses with tolperisone.

METHODS

An observational study of acute overdoses of tolperisone, either alone or in combination with one non-steroidal anti-inflammatory drug in a dose range not expected to cause central nervous system effects, in adults and children (< 16 years), reported to our poison centre between 1995 and 2013.

RESULTS

75 cases were included: 51 females (68%) and 24 males (32%); 45 adults (60%) and 30 children (40%). Six adults (13%) and 17 children (57%) remained asymptomatic, and mild symptoms were seen in 25 adults (56%) and 10 children (33%). There were nine adults (20%) with moderate symptoms, and five adults (11%) and three children (10%) with severe symptoms. Signs and symptoms predominantly involved the central nervous system: somnolence, coma, seizures and agitation. Furthermore, some severe cardiovascular and respiratory signs and symptoms were reported. The minimal dose for seizures and severe symptoms in adults was 1500 mg. In 11 cases the latency between the ingestion and the onset of symptoms was known and was reported to be 0.5-1.5 h.

CONCLUSIONS

The acute overdose of tolperisone may be life-threatening, with a rapid onset of severe neurological, respiratory and cardiovascular symptoms. With alternative muscle relaxants available, indications for tolperisone should be rigorously evaluated.

Atypical antipsychotic poisoning in young children: a multicentre analysis of poisons centres data

Although paediatric patients frequently suffer from intoxications with atypical antipsychotics, the number of studies in young children, which have assessed the effects of acute exposure to this class of drugs, is very limited. The aim of this study was to achieve a better characterization of the acute toxicity profile in young children of the atypical antipsychotics clozapine, olanzapine, quetiapine, and risperidone. We performed a multicentre retrospective analysis of cases with atypical antipsychotics intoxication in children younger than 6 years, reported by physicians to German, Austrian, and Swiss Poisons Centres for the 9-year period between January 1, 2001 and December 31, 2009. One hundred and six cases (31 clozapine, 29 olanzapine, 12 quetiapine, and 34 risperidone) were available for analysis. Forty-seven of the children showed minor, 28 moderate, and 2 severe symptoms. Twenty-nine cases were asymptomatic. No fatalities were recorded. Symptoms predominantly involved the central nervous and cardiovascular systems. Minor reduction in vigilance (Glasgow Coma Scale score >9) (62 %) was the most frequently reported symptom, followed by miosis (12 %) and mild tachycardia (10 %). Extrapyramidal motor symptoms were observed in one case (1 %) after ingestion of risperidone. In most cases, surveillance and supportive care were sufficient to achieve a good outcome, and all children made full recovery.

CONCLUSIONS

Paediatric antipsychotic exposure can result in significant poisoning; however, in most cases only minor or moderate symptoms occurred and were followed by complete recovery. Symptomatic patients should be monitored for central nervous system depression and an electrocardiogram should be obtained.

Seizures after single-agent overdose with pharmaceutical drugs: analysis of cases reported to a poison center

CONTEXT

Seizures during intoxications with pharmaceuticals are a well-known complication. However, only a few studies report on drugs commonly involved and calculate the seizure potential of these drugs.

OBJECTIVES

To identify the pharmaceutical drugs most commonly associated with seizures after single-agent overdose, the seizure potential of these pharmaceuticals, the age-distribution of the cases with seizures and the ingested doses.

METHODS

A retrospective review of acute single-agent exposures to pharmaceuticals reported to the Swiss Toxicological Information Centre (STIC) between January 1997 and December 2010 was conducted. Exposures which resulted in at least one seizure were identified. The seizure potential of a pharmaceutical was calculated by dividing the number of cases with seizures by the number of all cases recorded with that pharmaceutical. Data were analyzed using descriptive statistics.

RESULTS

We identified 15,441 single-agent exposures. Seizures occurred in 313 cases. The most prevalent pharmaceuticals were mefenamic acid (51 of the 313 cases), citalopram (34), trimipramine (27), venlafaxine (23), tramadol (15), diphenhydramine (14), amitriptyline (12), carbamazepine (11), maprotiline (10), and quetiapine (10). Antidepressants were involved in 136 cases. Drugs with a high seizure potential were bupropion (31.6%, seizures in 6 of 19 cases, 95% CI: 15.4-50.0%), maprotiline (17.5%, 10/57, 95% CI: 9.8-29.4%), venlafaxine (13.7%, 23/168, 95% CI: 9.3-19.7%), citalopram (13.1%, 34/259, 95% CI: 9.5-17.8%), and mefenamic acid (10.9%, 51/470, 95% CI: 8.4-14.0%). In adolescents (15-19y/o) 23.9% (95% CI: 17.6-31.7%) of the cases involving mefenamic acid resulted in seizures, but only 5.7% (95% CI: 3.3-9.7%) in adults (≥ 20y/o; p < 0.001). For citalopram these numbers were 22.0% (95% CI: 12.8-35.2%) and 10.9% (95% CI: 7.1-16.4%), respectively (p = 0.058). The probability of seizures with mefenamic acid, citalopram, trimipramine, and venlafaxine increased as the ingested dose increased.

CONCLUSIONS

Antidepressants were frequently associated with seizures in overdose, but other pharmaceuticals, as mefenamic acid, were also associated with seizures in a considerable number of cases. Bupropion was the pharmaceutical with the highest seizure potential even if overdose with bupropion was uncommon in our sample. Adolescents might be more susceptible to seizures after mefenamic acid overdose than adults. "Part of this work is already published as a conference abstract for the XXXIV International Congress of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) 27-30 May 2014, Brussels, Belgium." Abstract 8, Clin Toxicol 2014;52(4):298.

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.