Unintentional exposure to pregabalin in ≤6-year-old children: a nationwide French Poison Control Center study

High-flow continuous hemodiafiltration successfully decreased blood pregabalin levels in a patient with severe pregabalin intoxication: a case report

Background

Severe pregabalin intoxication may cause serious symptoms, such as coma. Since pregabalin is a small molecule with no protein binding sites and has low volume of distribution, hemodialysis can be effective in eliminating pregabalin from the blood. However, in cases of emergency, it is not always possible to perform hemodialysis because of limited availability and time delay associated with using the plumbing equipment. Continuous hemodiafiltration (CHDF) can be performed without plumbing equipment; however, the knowledge on the effectiveness of CHDF in pregabalin elimination is insufficient.

Case presentation

A septuagenarian woman with normal renal function was found in a collapsed state with symptoms of coma and miosis. Empty medical bags of pregabalin (2350 mg), bepotastine besilate (600 mg), celecoxib (4600 mg), quetiapine fumarate (87.5 mg), clotiazepam (180 mg), and teprenone (50 mg) were found around her. During the patient's transfer to our hospital, her cognition worsened and she developed glossoptosis necessitating her emergent intubation upon arrival. We considered that the coma was mainly caused by pregabalin intoxication and were concerned about the consequent critical comorbidities. Thus, we performed CHDF in a high-flow setting in our intensive care unit for pregabalin elimination. After 8 h of CHDF, the patient regained consciousness, and after 6.5 h we extubated her. At a later date, we measured her serum pregabalin levels during the clinical course and estimated the blood pregabalin clearance levels depending on her metabolism as 76.8 mL/min and depending on CHDF itself as 65.1 mL/min. Based on these findings, we concluded that CHDF contributed to reducing blood pregabalin levels in this patient.

Conclusions

Our case revealed that pregabalin clearance using CHDF is similar to metabolic clearance in patients with normal renal function, indicating that CHDF decreases blood pregabalin levels and can be a potential treatment for severe pregabalin intoxication.

Possible impact of the COVID-19 pandemic on the recreational use of nitrous oxide in the Paris area, France

INTRODUCTION

Recreational use of nitrous oxide (N₂O) is increasing in Western countries, including France. During the COVID-19 pandemic, some authors warned that recreational N₂O use could increase further as the supply of illicit drugs was impacted by various containment measures.

METHODS

We retrospectively analyzed N₂O exposures reported to the Paris Poison Control Center (France) from 2010/01/01 to 2021/04/15. The Poison Severity Score was used to grade severity.

RESULTS

During the study period, 93 cases of N₂O recreational exposures were reported (male/female ratio: 1.1; median age: 20.9 years range: [14.8-49.0]). The first case was reported in 2012, 84/93 (90%) and 65/93 (70%) were reported since 2019 and March 17^th 2020 (first lockdown in France) respectively. Most of the patients were symptomatic (88/93; 95%) and developed neurological symptoms (78/93; 84%). Among the fourteen patients who developed moderate to severe symptoms, eleven were reported after March 2020.

CONCLUSION

Despite a marked increase in recreational N₂O exposures during the COVID-19 pandemic, the exact impact of COVID-19 on this increase remains to be determined as it was observed from 2019.

Exposure to immediate-release tramadol in children 6 years and under - a nationwide French poison control center study

INTRODUCTION

Data regarding immediate-release (IR)-tramadol exposures in children remain sparse. We aimed to investigate the incidence of IR-tramadol exposures in ≤6-year-old children, to describe the characteristics and resulting outcome of ingestions involving IR-tramadol alone, and to estimate a clinically relevant toxic dose in this population.

METHODS

Retrospective analysis of IR-tramadol exposures in ≤6-year-old children, collected by the French Poison Control Centers (PCCs) in 2003-2019. The incidence was estimated using IR-tramadol prescription data from the Health Improvement Network database (the French version of THIN). The Poison severity score (PSS) was used to grade severity.

RESULTS

We found 1260 IR-tramadol exposures in ≤6-year-old children. The number of cases per 100,000 IR-tramadol-treated patients increased over time (p < .0001). One hundred forty-five cases involving IR-tramadol alone were analyzed. The median age was 3.0 years (IQR: 1.9, 4.0), the M/F ratio was 1.5 and the median dose was 5.0 mg/kg (IQR 3.3-11.1). Half of the children (49.7%) remained asymptomatic (PSS0) while 29.6% and 14.5% developed minor (PSS1) or moderate-to-severe (PSS2-PSS3) neurological symptoms, respectively. Twelve children developed respiratory depression. No seizures and no fatality were reported. All symptomatic children recovered within 24 h. The ingested IR-tramadol dose was positively correlated with the PSS (p < .0001). Using a receiver operating characteristic (ROC) curve approach (area under the curve, 0.92; p < .001), ingestion of ≥7.4 mg/kg IR-tramadol was appropriate to recommend hospital referral (sensitivity, 100% [95% confidence interval (CI), 85-100]; specificity, 73% [95% CI, 64-80]; predictive positive value, 39% [95% CI, 35-57]; negative predictive value, 100% [95% CI, 96-100]). Children who ingested <7.4 mg/kg IR-tramadol developed no (n = 68) or minor (n = 22) neurological symptoms.

CONCLUSIONS

Despite increasing tramadol prescriptions in adults during the study period in France, oral exposure to IR-tramadol in ≤6-year-old children was rare but possibly responsible for severe toxicity. Children with no underlying disease and concomitant medication ingesting <7.4 mg/kg IR-tramadol alone could be observed at home. However, given the observed variability in the onset of seizures after tramadol ingestion, which can occur at ingested tramadol doses below 7.4 mg and even at therapeutic doses, parents or guardians should be specifically warned about the risk of seizures.

Pregabalin poisoning: Evaluation of dose-toxicity relationship

Context

Pregabalin poisoning is mostly benign, although coma and convulsions occasionally occur.

Aim

To determine the dose‐toxicity relationship of pregabalin.

Methods

Dose‐toxicity data of isolated pregabalin poisonings were collected from (1) a prospective study performed by the Dutch Poisons Information Centre (4 April 2014 to 4 October 2016) and from (2) case reports and case series reported in literature. Poisonings were graded using the Poisoning Severity Score (PSS) and the relationship between dose (mg kg⁻¹) and PSS was evaluated.

Results

In our study (n = 21 patients), the most commonly observed symptoms were drowsiness (62%), confusion (29%) and apathy (24%). PSS was none in three (14%), minor in 15 (71%), and moderate in three patients (14%). Most case series also reported a PSS of none to minor in the majority of poisonings (69‐100%). For 34 individual patients (21 from our study and 13 from literature), detailed data on dose and clinical course were available to examine the dose‐toxicity relationship.

The median dose was significantly lower in the PSS none‐minor group (“benign”) (8.6 mg kg⁻¹, interquartile range (IQ25‐75) 5.0‐17.6 mg kg⁻¹) than in the PSS moderate‐severe group (“significant toxicity”) (46.7 mg kg⁻¹, IQ25‐75 21.3‐64.3 mg kg⁻¹); estimate of the median difference = 27.3 mg kg⁻¹ (95% confidence interval (CI): 10‐48.6).

Conclusions

In general, higher pregabalin doses result in more severe poisonings. Below 20 mg kg⁻¹ the majority of patients (83%) only suffer from mild poisoning. However, large interindividual differences exist in pregabalin‐induced toxicity. Therefore, pre‐hospital triage should not only include pregabalin dose, but also underlying illnesses, co‐exposures and reported symptoms.

Increase in pregabalin recreational use in adolescents in France

INTRODUCTION

Misuse/abuse of pregabalin is increasing worldwide. French Poison Control Centers (PCCs) recently received several unusual calls regarding the recreational use of pregabalin in adolescents. This study aims to describe this new and specific population of pregabalin misusers.

METHODS

We extracted all cases of pregabalin intentional exposures reported to the French National Database of Poisonings (FNDP) from 2004 to 2020. We compared the proportion of recreational exposure to pregabalin between adolescents (10-17 years) and adults (>18 years). We reviewed all cases of pregabalin recreational exposures in adolescent in order to describe the characteristics of this population.

RESULTS

During the study period, 382 cases of acute intentional exposure to pregabalin were reported in adolescents and 1188 in adults, 94/382 (24.6%) and 43/1188 (3.6%) were pregabalin recreational use, respectively (p < .0001). Almost all cases of pregabalin recreational use in adolescent were reported from 2018 (86/94; 91%). Most of those adolescent patients were males (male/female ratio - 5.3:1) and the median age was 15 years (range: 11-17.8). They were homeless or living in migrant shelters in most of the cases (73/90, 81%). Two-third of these exposures (62/94; 66%) involved other toxicant(s) than pregabalin. Most of the patients remains asymptomatic (10/94; 11%), or developed minor to moderate neurological symptoms (76/94; 81%). Eight developed severe symptoms (8/94; 8%) including coma (5/8) or generalized seizures (2/8). Five patients (5/8) required oro-tracheal intubation. No fatality was reported.

CONCLUSIONS

We observed a sharp increase in pregabalin recreational use in adolescents in France. It should lead to prevention campaigns, targeted at the population at risk described in this study.