Extracorporeal treatment for poisoning to beta-adrenergic antagonists: systematic review and recommendations from the EXTRIP workgroup

BACKGROUND

β-adrenergic antagonists (BAAs) are used to treat cardiovascular disease such as ischemic heart disease, congestive heart failure, dysrhythmias, and hypertension. Poisoning from BAAs can lead to severe morbidity and mortality. We aimed to determine the utility of extracorporeal treatments (ECTRs) in BAAs poisoning.

METHODS

We conducted systematic reviews of the literature, screened studies, extracted data, and summarized findings following published EXTRIP methods.

RESULTS

A total of 76 studies (4 in vitro and 2 animal experiments, 1 pharmacokinetic simulation study, 37 pharmacokinetic studies on patients with end-stage kidney disease, and 32 case reports or case series) met inclusion criteria. Toxicokinetic or pharmacokinetic data were available on 334 patients (including 73 for atenolol, 54 for propranolol, and 17 for sotalol). For intermittent hemodialysis, atenolol, nadolol, practolol, and sotalol were assessed as dialyzable; acebutolol, bisoprolol, and metipranolol were assessed as moderately dialyzable; metoprolol and talinolol were considered slightly dialyzable; and betaxolol, carvedilol, labetalol, mepindolol, propranolol, and timolol were considered not dialyzable. Data were available for clinical analysis on 37 BAA poisoned patients (including 9 patients for atenolol, 9 for propranolol, and 9 for sotalol), and no reliable comparison between the ECTR cohort and historical controls treated with standard care alone could be performed. The EXTRIP workgroup recommends against using ECTR for patients severely poisoned with propranolol (strong recommendation, very low quality evidence). The workgroup offered no recommendation for ECTR in patients severely poisoned with atenolol or sotalol because of apparent balance of risks and benefits, except for impaired kidney function in which ECTR is suggested (weak recommendation, very low quality of evidence). Indications for ECTR in patients with impaired kidney function include refractory bradycardia and hypotension for atenolol or sotalol poisoning, and recurrent torsade de pointes for sotalol. Although other BAAs were considered dialyzable, clinical data were too limited to develop recommendations.

CONCLUSIONS

BAAs have different properties affecting their removal by ECTR. The EXTRIP workgroup assessed propranolol as non-dialyzable. Atenolol and sotalol were assessed as dialyzable in patients with kidney impairment, and the workgroup suggests ECTR in patients severely poisoned with these drugs when aforementioned indications are present.

Persistent wheezing caused by carvedilol overdose in a non-asthmatic man

Background

Cardiovascular dysfunction is the main manifestation of β‐blocker intoxication; however, respiratory manifestations have rarely been reported.

Case Presentation

A 41‐year‐old man, who had ingested 300 mg carvedilol in a suicide attempt, was transferred to our emergency department. The patient had wheezing on arrival; however, he had no known history of bronchial asthma. In the absence of signs of heart failure, we gave the patient inhaled procaterol, a short‐acting β2 agonist. The wheezing disappeared approximately 60 h after carvedilol ingestion and did not recur thereafter.

Conclusion

We report a case of wheezing caused by carvedilol intoxication. Although rare, clinicians should recognize that wheezing or bronchospasm can develop following β‐blocker intoxication, for which a short‐acting β2 agonist could be indicated.

Poison-related visits in a pediatric emergency department: A retrospective analysis of patients who bypass poison control centers

INTRODUCTION

Poison control centers (PCC) are an effective means to prevent unnecessary emergency department (ED) visits associated with poisoning exposures. However, not all patients with poison exposures utilize the PCC. The purpose of this study was to identify unintentional pediatric poisoning exposures presenting to a large US children's hospital that could have been managed onsite (i.e., at home) if consultation with a PCC had occurred prior to the ED visit.

METHODS

Using ED encounters from a tertiary children's hospital, unintentional pharmaceutical, chemical, or fume exposures occurring between October 1, 2014 and September 30, 2015 were identified from ICD-9-CM billing codes. Two specialists in poison information reviewed the medical records of the identified patients who had no contact with the PCC and determined whether these encounters were preventable through PCC triage. Descriptive statistics examined the differences between the encounters. Data were analyzed in R v3.2.4 (Vienna, Austria) and SAS v9.4 (SAS Institute, Cary, NC).

RESULTS

In the total study population (n = 231), 98 (42.4%) were PCC triaged and 133 (57.6%) were caregiver self-referred to the ED. For those who self-referred, 62 (46.6%) patients would have been recommended to be managed onsite instead of presenting at the ED for medical care. Analgesics and household cleaning products were the most common pharmaceutical and chemical exposures, respectively.

CONCLUSIONS

Nearly half of ED visits for pediatric patients with unintentional poisoning exposures could have been avoided by contacting a PCC. Educational and self-efficacy-based interventions are needed to expand the public's use of PCC services.

Clinical toxicology of beta-blocker overdose in adults

Beta-blocker overdose is potentially harmful due to the strong blood pressure-lowering and heart rate-lowering effects. However, conflicting data exist as to their differential toxicity, single-substance exposures and the effect of co-exposure with additional antihypertensive medication. For this, a 10-year retrospective, explorative analysis of the Mainz Poison Center/Germany database with regard to circumstances of beta-blocker exposure, doses, symptoms and treatment was carried out. Analyses were restricted to adult patients with single-substance exposures and co-exposures with one additional antihypertensive substance. Written follow-up information was obtained in half the cases. A total of 2967 cases were analysed, of which 697 were single-substance exposures. Metoprolol was most frequently reported followed by bisoprolol, atenolol, propranolol and sotalol. Metoprolol showed a linear dose-symptom relationship, whereas propranolol and sotalol seemed to have a threshold dose beyond which symptoms aggravated. Symptoms did not differ substantially, except for more seizures being reported with propranolol, and more CNS depression/vomiting with sotalol. Activated charcoal was used in 38%, gastric lavage in 11%, temporary pacemaker in 3%, glucagon in 1%, intubation for respiratory insufficiency and cardiopulmonary resuscitation in 1% and 0.5%. All patients recovered. In 174 co-exposure cases, the distribution of poisoning severity and rate of worsening of symptoms was comparable with single-substance exposures except one patient deceased after bisoprolol and verapamil co-exposure. In adults with beta-blocker overdose, no significant differences in poisoning severity among beta-blockers were detected, and no fatalities were observed with single-substance exposures. Co-exposures with other antihypertensives, sedatives or alcohol should be carefully attended to as fatalities might occur.

A 10-year review of single medication double-dose ingestions in the nation's largest poison control system

BACKGROUND

Most Americans take at least one medication on a daily basis. Inadvertently ingesting a double-dose of a medication with a narrow therapeutic index may lead to adverse effects. When a patient or medical professional contacts the local poison center after an overdose, a poison specialist fields the incoming information and, depending on the caller, provides specific recommendations. We sought to determine which medication classes were most likely to lead to significant adverse outcomes when an extra dose was ingested.

METHODS

This was a retrospective review of all double-dose medication ingestions reported to the California Poison Control System (CPCS) between January 2006 and December 2015. Inclusion criteria were single-instance, single-medication ingestions where the dose was known. All ages and both sexes were included. We evaluated generalized outcomes per AAPCC criteria stratified as no effect, minor, moderate, major or death. We also documented specific symptoms and interventions noted by the poison control specialists.

RESULTS

Out of 1286 cases, 876 ingestions met the inclusion criteria. Medications with antihypertensive and behavior modulating effects each accounted for over a third of all moderate and major effects. The medications/medication classes implicated in the 12 major outcomes included propafenone, beta blockers (βBs), calcium channel blockers (CCBs), bupropion, and tramadol. Of these, vasoactive medications were associated with the most severe effects requiring cardiac pacing and vasopressor drips. Analgesics, antimicrobials, and anti-allergy medications were well tolerated. There were no deaths.

CONCLUSIONS

Major adverse outcomes after a double dose ingestion were rare. Most double dose medication ingestions can be safely monitored at home, albeit with a few exceptions. Vigilance is warranted in cases of βB and CCB ingestion due to the risk of hemodynamic collapse or seizures with tramadol and bupropion.

β-Blocker and Calcium Channel Blocker Poisoning: High-Dose Insulin/Glucose Therapy

Overdoses of β-blockers and calcium channel blockers can produce significant morbidity and mortality, and conventional therapies often do not work as treatments for these poisonings. High-dose insulin/glucose therapy has been successful in reversing the cardiotoxic effects of these drugs in cases where the standard therapies have failed, and it appears to be relatively safe. Many successes have been well documented, but the clinical experience consists of case reports, the mechanisms of action are not completely understood, and guidelines for use of the therapy are empirically derived and not standardized. Regardless of these limitations, high-dose insulin/glucose therapy can be effective, it is often recommended by clinical toxicologists and poison control centers, and critical care nurses should be familiar with when and how the therapy is used.

Severe carvedilol toxicity without overdose - caution in cirrhosis

Background

Carvedilol is used in the management of hypertension, ischemic heart disease, heart failure and most recently, portal hypertension. It has been associated with improved outcomes regarding variceal bleeding, hepatic decompensation and death when compared to propranolol and endoscopic band ligation. The main cause of portal hypertension is cirrhosis and therefore carvedilol is increasingly used in these patients. Due to its extensive hepatic metabolism, carvedilol is contraindicated in severe hepatic impairment. However, there are no dosage adjustments in the manufacturer's labelling for mild to moderate hepatic impairment.

Case presentation

We present a case of cardiogenic shock that occurred after carvedilol 25 mg orally was administered to a patient with cirrhosis. As there was no overdose, the diagnosis was based on clinical recognition of the toxidrome. The patient was successfully treated with glucagon 5 mg bolus followed by infusion.

Conclusions

Patients with cirrhosis represent a special at-risk group for beta blocker toxicity. The typical threshold for carvedilol toxicity in overdose is 50 mg but in patients with cirrhosis this is not applicable. Nurses and physicians need to recognize the toxidrome early. Hospitals where carvedilol is used in patients with cirrhosis should have glucagon in formulary at doses to treat toxicity (bolus and infusion). Finally, dose adjustment and slow uptitration of carvedilol in cirrhosis is recommended.

Eszopiclone ingestions reported to Texas poison control centers, 2005—2006

Eszopiclone is a nonbenzodiazepine hypnotic for the treatment of insomnia and classified as schedule IV controlled substance. Limited information exists on eszopiclone ingestions reported to poison control centers. The distribution of eszopiclone ingestions reported to Texas poison control centers during 2005—2006 was determined for various factors. In addition, triage guidelines for the management of such ingestions were drafted. Of 525 total eszopiclone ingestions, 259 involved coingestants. Of coingestant cases, 78.8% involved suspected attempted suicide and 90.7% were managed at a healthcare facility. Of 266 ingestions of eszopiclone alone, 40.2% were suspected attempted suicide and 62.0% were managed at a healthcare facility. A final medical outcome and dose ingested were known for 60 ingestions of eszopiclone alone. The mean dose was 28.3 mg (range 0.3—210 mg). Ingestions of eszopiclone alone of ≤6 and >6 mg differed with respect to the proportion involving suspected attempted suicide (0.0% versus 64.7%), final medical outcome of minor or moderate effect (38.5% versus 67.6%) and management at a healthcare facility (34.6% versus 91.2%). Using 6 mg as a threshold dose for referral to a healthcare facility, 78% of cases not already at/en route to a healthcare facility were managed according drafted triage guidelines. Human & Experimental Toxicology (2007) 26, 795— 800

Pediatric lisinopril ingestions reported to Texas poison control centers

Lisinopril is not recommended for use by young children. This study attempted to identify factors associated with serious outcomes in pediatric lisinopril ingestions. Cases for this study were lisinopril ingestions by children age ≤5 years reported to Texas poison control centers during 1998- 2005. The percentage of cases involving serious medical outcomes was identified for selected variables and evaluated for statistical significance by calculating the rate ratio (RR) and 95% confidence interval (CI). Of 691 total cases, 26 (3.8%) involved a serious outcome. Higher serious outcome rates were found with a max imum dose of >4 mg/kg (RR: 2.54, CI: 0.05-25.62), or > 80 mg (RR: 7.85; CI: 1.73-29.29),or five or more tablets (RR: 8.18; CI: 2.73-22.54), or the patient was already at or en route to a health care facility when the poison control center was contacted (RR: 13.93; CI: 3.68-77.78),or referred to a health care facility by the poison control center (RR: 33.49; CI: 9.04-194.94). The management of patients with severe outcomes was more likely to involve health care facilities. This information is useful for drafting triage guidelines for the management of pediatric lisinopril ingestions. Human & Experimental Toxicology (2007) 26 , 83- 89

Toxicology in the ICU: Part 2: specific toxins

This is the second of a three-part series that reviews the generalized care of poisoned patients in the ICU. This article focuses on specific agents grouped into categories, including analgesics, anticoagulants, cardiovascular drugs, dissociative agents, carbon monoxide, cyanide, methemoglobinemia, cholinergic agents, psychoactive medications, sedative-hypnotics, amphetamine-like drugs, toxic alcohols, and withdrawal states. The first article discussed the general approach to the toxicology patient, including laboratory testing; the third article will cover natural toxins.

Adult metaxalone ingestions reported to Texas poison control centers, 2000-2006

Few data exist on potentially adverse metaxalone (Skelaxin®) ingestions in adults. All metaxalone ingestions involving patients aged ≥20 years during 2000-2006 were retrieved from Texas poison control centers. Exclusion criteria were lack of follow-up or multiple substance ingestion. Cases were analyzed for selected demographic and clinical factors. Of the 142 patients, 66.2% were female. Dose ingested was reported for 61 patients. Of those cases with a reported dose, distribution by management site was 29.5% on-site, 59.0% already at/en route to health care facility, and 11.5% referred to health care facility. Final medical outcome was ‘no effect’ for 50.8% cases, ‘minor effect’ for 31.1%, and ‘moderate effect’ for 18.0%. The more common adverse clinical effects reported were drowsiness (27.9%), tachycardia (6.6%), agitation (6.6%), nausea (4.9%), dizziness (4.9%), slurred speech (4.9%), and tremor (4.9%). A moderate medical outcome occurred in 13.6% of ingestions of ≤2400 mg and 20.5% of ingestions of >2400 mg. Management involved a health care facility in 18.2% of ingestions of ≤2400 mg and 100.0% of ingestions of >2400 mg. This study found that adult ingestions of higher doses of metaxalone, particularly >2400 mg, were associated with more serious medical outcomes and were managed at health care facilities. This study also proposes triage guidelines for when ingestions can be safely managed at home.

Immediate- and controlled-release zolpidem ingestions reported to Texas poison centers

Zolpidem is available in immediate-release (IR) and controlled-release (CR) formulations. This investigation examined whether there were differences in zolpidem IR and CR ingestions reported to poison control centers. Zolpidem ingestions that did not involve coingestants reported to Texas poison control centers during 2005-2008 were identified. The ingestions were grouped by IR and CR formulations and compared with respect to demographic and clinical factors. There were 734 IR and 163 CR ingestions. The mean dose ingested was 92.9 mg and 104.6 mg, respectively. IR and CR cases were, respectively, 56.9% and 58.3% male, 54.6% and 49.7% age >19 years, 65.0% and 65.0% already at or en route to a health care facility when the poison control center was contacted, and 30.1% and 39.3% involved no effect. The most frequently reported adverse clinical effects were, for IR and CR, respectively, drowsiness (54.4% vs 42.3%), tachycardia (10.6% vs 11.7%), ataxia (6.3% vs 11.7%), slurred speech (6.3% vs 6.7%), vomiting (5.0% vs 5.5%) and hallucinations/delusions (4.9% vs 3.1%). The distribution of zolpidem IR and CR ingestions reported to Texas poison control centers were similar. However, zolpidem CR ingestions appeared less likely to result in drowsiness and hallucinations but more likely to result in ataxia.

Comparison of Immediate-Release and Controlled-Release Paroxetine Ingestions Reported to Texas Poison Control Centers between 2002 and 2008

Background:

Controlled-release (CR) paroxetine was created to improve the tolerability of immediate-release (IR) paroxetine while maintaining therapeutic benefits. There is limited information comparing the toxicity of the 2 paroxetine formulations.

Objective:

To compare the toxicity and management of paroxetine IR and paroxetine CR ingestions reported to poison control centers.

Methods:

Cases of ingestion of paroxetine that were reported to Texas poison control centers between 2002 and 2008, in which the final medical outcome and dose were known, were retrospectively reviewed. The rates for selected variables were determined for paroxetine IR and paroxetine CR and comparisons between the 2 were made by calculating the ratio of the drug's CR rate to the IR rate and 95% confidence interval. Compliance with simplified algorithms of triage management guidelines was determined for both formulations.

Results:

Included in the analysis were 405 cases of paroxetine IR ingestion and 169 cases of paroxetine CR ingestion for which a reported dose and final medical outcome were known. There were no statistically significant differences between the paroxetine CR and paroxetine IR formulations with respect to serious medical outcomes (ratio 0.69, 95% CI 0.34 to 1.31), self-harm or malicious intent (ratio 0.82, 95% CI 0.60 to 1.12), or referral to a healthcare facility (ratio 1.18, 95% CI 0.76 to 1.83). The rate of compliance with the triage algorithm for cases not already en route to or at a healthcare facility when the poison control center was contacted was 87% for paroxetine IR and 89% for paroxetine CR.

Conclusions:

The toxicity and management of paroxetine IR and paroxetine CR ingestions reported to Texas poison control centers were similar after adjusting for differences in dosage.

Adult metformin ingestions reported to Texas poison control centers, 2000–2006

Metformin is an oral hypoglycemic agent used in the management of type 2 diabetes mellitus. Limited information exists on adult metformin ingestions reported to poison control centers. The distribution of adult metformin ingestions reported to Texas poison control centers during 2000–2006 was determined for various factors. In addition, triage guidelines for the management of isolated ingestions were drafted. Of 1528 total metformin ingestions, 58% involved coingestants. Of the 264 ingestions of metformin alone, where the final medical outcome was known, dose ingested was reported for 66%. The mean reported dose was 4739 mg (range 500–60,000 mg). Ingestions of ≤2500 mg and >5000 mg reported doses differed with respect to the proportion involving suspected attempted suicide (6% versus 81%), serious final medical outcome (3% versus 19%), and referral to a health care facility (3% versus 83%). Using 5000 mg as a threshold dose for referral to a health care facility, 91% of cases not already at or en route to a health care facility were managed according drafted triage guidelines.

Adult lisinopril ingestions reported to Texas poison control centers, 1998—2005

There is limited information on potentially adverse lisinopril ingestions reported to poison control centers. Using adult lisinopril ingestions reported to Texas poison control centers during 1998—2005, the proportion of cases involving serious outcomes was determined for selected variables and evaluated for statistical significance by calculating the rate ratio (RR) and 95% confidence interval (CI). Of 468 cases identified, 43 (9%) involved serious outcomes. The severity of the outcome associated with adult lisinopril ingestions depended on the dose and the circumstances of the ingestion. Thus, serious outcomes were significantly more likely to occur with a maximum dose >80 mg (RR 5.69, CI 2.43—13.33) or, if the dose was unknown, ≥3 tablets (RR 9.57, CI 2.39—54.97), where the circumstances of the exposures involved self-harm or malicious intent (RR 6.96, CI 3.65—13.31), or the patient was already at or en route to a health care facility when the poison control center was contacted (RR 7.33, CI 3.09—17.85) or referred to a health care facility by the poison control center (RR 23.76, CI 10.62—55.67). The management of patients with severe outcomes was more likely to involve health care facilities. Such information is useful for creating of triage guidelines for the management of adult lisinopril ingestions. Human & Experimental Toxicology (2007) 26, 483—489

Adult atomoxetine ingestions reported to Texas Poison Control Centers, 2003-2005

BACKGROUND

Limited information exists on outcomes from adult ingestions of atomoxetine reported to poison control centers.

OBJECTIVE

To identify factors that might affect the outcome of adult atomoxetine ingestions reported to poison control centers.

METHODS

Using adult ingestions of atomoxetine alone reported to Texas poison control centers during 2003-2005, the proportion of cases involving serious outcomes was determined for selected variables and evaluated for statistical significance by calculating the rate ratio (RR) and 95% confidence interval (CI).

RESULTS

Of 64 cases identified, 9 (14%) involved serious outcomes. No serious outcomes were reported with a maximum dose of 100 mg or less. Serious outcomes were significantly more likely to occur with a maximum dose of more than 2 capsules (RR 8.25; 95% CI 1.48 to 83.58), where the circumstances of the exposures involved self-harm or malicious intent (RR 6.02; 95% CI 1.30 to 30.35) or when the patient was already at or en route to a healthcare facility when the poison control center was contacted (RR 18.75; 95% CI 2.10 to 886.83) or was referred to a healthcare facility by the poison control center (RR 22.50; 95% CI 1.81 to 1181.19).

CONCLUSIONS

The severity of the outcomes associated with adult atomoxetine ingestions depended on the dose taken and the circumstances of the ingestion. The management of patients with serious outcomes was more likely to involve healthcare facilities. Such information is useful in creating triage guidelines for the management of adult atomoxetine ingestions.

Treatment of poisoning caused by β-adrenergic and calcium-channel blockers

PURPOSE

The toxic effects and treatment of beta-adrenergic blocker and calcium-channel blocker (CCB) overdose are reviewed.

SUMMARY

Overdoses with cardiovascular drugs are associated with significant morbidity and mortality. Beta-blockers and CCBs represent the most important classes of cardiovascular drugs. In overdose, beta-blockers and CCBs have similar presentation and treatment overlaps and are often refractory to standard resuscitation measures. The common feature of beta-blocker toxicity is excessive blockade of the beta-receptors resulting in bradycardia and hypotension. Poisoning by CCBs is characterized by cardiovascular toxicity with hypotension and conduction disturbances, including sinus bradycardia and varying degrees of atrioventricular block. Therapies include beta-agonists, glucagon, and phosphodiesterase inhibitors. However, in beta-blocker poisoning where symptomatic bradycardia and hypotension are present, high-dose glucagon is considered the first-line antidote. Traditionally, antidotes for CCB overdose have included calcium, glucagon, adrenergic drugs, and amrinone. For cases of CCB poisoning where cardiotoxicity is evident, first-line therapy is a combination of calcium and epinephrine; high-dose insulin with supplemental dextrose and potassium therapy (HDIDK) is reserved for refractory cases. Health-system pharmacists should be aware that when these drugs are used as antidotes, higher than normal dosing is needed.

CONCLUSION

Poisoning by beta-blockers or CCBs usually produces hypotension and bradycardia, which may be refractory to standard resuscitation measures. For cases of beta-blocker poisoning where symptomatic bradycardia and hypotension are present, high-dose glucagon is considered the first-line antidote. For cases of CCB poisoning where cardiotoxicity is evident, a combination of calcium and epinephrine should be used initially, reserving HDIDK for refractory cases.