Extracorporeal treatment for calcium channel blocker poisoning: systematic review and recommendations from the EXTRIP workgroup

Association of Calcium Channel Blocker Use With Intradialytic Hypotension in Maintenance Hemodialysis

Introduction

Calcium channel blockers (CCBs) are common antihypertensive agents among patients receiving hemodialysis (HD). Despite this, the association of CCBs with intradialytic hypotension (IDH), an important adverse outcome that is associated with cardiovascular morbidity and mortality, remains largely unexplored.

Methods

Using kinetic modeling sessions data from the Hemodialysis (HEMO) Study, random effects regression models were fit to assess the association of CCB use versus nonuse with IDH (defined as systolic blood pressure [SBP] < 90 mm Hg if pre-HD SBP < 160 mm Hg or < 100 mm Hg if pre-HD SBP ≥160 mm Hg). Models were adjusted for age, biological sex (distinguishing between males and females), race, randomized Kt/V and flux assignments, heart failure, ischemic heart disease, peripheral vascular disease, diabetes mellitus, blood urea nitrogen, ultrafiltration rate, access type, pre-HD SBP, and other antihypertensives.

Results

Data were available for 1838 patients and 64,538 sessions. At baseline, 49% of patients were prescribed CCBs. The overall frequency of IDH was 14% with a mean decline from pre- to nadir-SBP of 33 ± 15 mm Hg. CCB use was associated with lower adjusted risk of IDH, compared with no use (incidence rate ratio [IRR]: 0.84; 95% confidence interval [CI]: 0.78-0.89). The association was most pronounced for those in the pre-HD SBP lowest quartile (IRR: 0.77; 95% CI: 0.70-0.85); compared with the highest quartile (IRR: 0.86; 95% CI: 0.77-0.97; P-interaction < 0.001).

Conclusion

Among patients receiving HD, CCB use was associated with a lower risk of developing IDH, independent of pre-HD SBP and other antihypertensives use. Mechanistic studies are needed to better understand the effects of CCB and other antihypertensives on peridialytic blood pressure (BP) parameters among patients receiving HD.

Metabolic management of accidental intoxication

PURPOSE OF REVIEW

Unintentional intoxication comprises a major chunk of all intoxications. Most patients are in the pediatric age group with another set of patients being the elderly. Substances found to cause accidental intoxication vary from country to country and even within different regions of a country. Frequent reviews of current literature are needed to be abreast of trends.

RECENT FINDINGS

Prescription drugs and household chemicals are major culprits when it comes to accidental intoxication. Acetaminophen, digoxin and metformin are some of the prominent prescription drugs frequently associated with unintentional intoxications. Increasingly alcohol based hand sanitizers are becoming an important etiology of these events, following their increased usage during the COVID-19 pandemic. Pattern recognition to identify class of intoxicant and supportive care including prevention of further absorption and increased excretion are cornerstones of therapy. Antidote when available should be used promptly.

SUMMARY

Knowledge about current epidemiology of accidental intoxications, toxidrome pattern recognition and appropriate antidote usage beside adequate and timely supportive care help in successful management of the unfortunate victim of accidental intoxication.

Beta-blocker and calcium-channel blocker toxicity: current evidence on evaluation and management

Beta-blocker and calcium-channel blocker overdoses are associated with severe morbidity and mortality; therefore, it is important to recognize and appropriately treat individuals with toxicity. The most common clinical findings in toxicity are bradycardia and hypotension. In addition to supportive care and cardiac monitoring, specific treatment includes administration of calcium salts, vasopressors, and high-dose insulin euglycaemia treatment. Other advanced treatments (e.g. ECMO) may be indicated depending on the severity of toxicity and specific agents involved.

Management of Poisonings and Intoxications

Poisoning occurs after exposure to any of a number of substances, including medicines, which can result in severe toxicity including death. The nephrologist may be involved in poisonings that cause kidney disease and for targeted treatments. The overall approach to the poisoned patient involves the initial acute resuscitation and performing a risk assessment, whereby the exposure is considered in terms of the anticipated severity and in the context of the patient's status and treatments that may be required. Time-critical interventions such as gastrointestinal decontamination ( e.g. , activated charcoal) and antidotes are administered when indicated. The nephrologist is usually involved when elimination enhancement techniques are required, such as urine alkalinization or extracorporeal treatments. There is increasing data to guide decision making for the use of extracorporeal treatments in the poisoned patient. Principles to consider are clinical indications such as whether severe toxicity is present, anticipated, and/or will persist and whether the poison will be significantly removed by the extracorporeal treatment. Extracorporeal clearance is maximized for low-molecular weight drugs that are water soluble with minimal protein binding (<80%) and low endogenous clearance and volume of distribution. The dosage of some antidotes ( e.g. , N-acetylcysteine, ethanol, fomepizole) should be increased to maintain therapeutic concentrations once the extracorporeal treatment is initiated. To maximize the effect of an extracorporeal treatment, blood and effluent flows should be optimized, the filter with the largest surface area selected, and duration tailored to remove enough poison to reduce toxicity. Intermittent hemodialysis is recommended in most cases when an extracorporeal treatment is required because it is the most efficient, and continuous kidney replacement therapy is prescribed in some circumstances, particularly if intermittent hemodialysis is not readily available.

High-dose insulin should be used before vasopressors/inotropes in calcium-channel blocker toxicity

High-dose insulin (HDI) therapy with adapted glucose supplementation to maintain euglycaemia has been suggested to treat calcium-channel blocker (CCB) poisonings. Its underlying mechanisms of action are now well documented. We present a narrative review of the published experimental studies, case reports and experts' opinions to support the effectiveness and safety of HDI in the treatment of CCB poisoning. Our review strongly encourages the use of HDI as first-line therapy in CCB-poisoned patients in the presence of cardiovascular compromise, especially if cardiac function impairment has been diagnosed, before, but without delaying, the administration of vasopressors/inotropic drugs.

[Hemoperfusion and plasmapheresis in the intensive care unit]

In addition to kidney replacement procedures, several other extracorporeal procedures are employed in the intensive care unit. Hemoperfusion with activated charcoal was the predominant treatment used for removal of toxins from the 1970s until the millennium. Nowadays, this treatment does no longer play a clinically meaningful role as even strongly protein-bound toxins can be removed by effective dialysis procedures in case poisoning. The concept of a cytokine adsorber was introduced 10 years ago, which is directed towards withstanding the cytokine storm. Despite negative data from prospective randomized controlled studies, its use is steadily increasing in Germany. A totally different treatment concept is the biomimetic pathogen adsorber, which removes bacteria, viruses and fungi from the bloodstream by binding to immobilized heparin. Whether this rapid reduction of the pathogen load translates into an improvement of clinically relevant endpoints is unclear, as prospective randomized controlled studies are lacking. For the early hours of septic shock a very old procedure, plasmapheresis, has recently regained interest. The results of two large randomized controlled studies in this setting from Europe and Canada will become available in 2025/2026. The rationale to use plasma exchange in early sepsis is that this procedure not only removes cytokines but also replenishes reduced levels of protective factors, such as angiopoietin‑1, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS-13) and protein C, if fresh plasma is used as exchange fluid. All afore mentioned procedures do not only have a different mode of action but are also used at seperate time points of bloodstream infections and/or sepsis.

QuEChERS-Based Approach to the Extraction of Five Calcium Channel Blockers from Plasma Determined by UPLC-MS/MS

Here, a QuEChERS (quick, easy, cheap, effective, rugged, and safe) pretreatment method was combined with UPLC-MS/MS to facilitate the rapid and reliable simultaneous detection of five calcium channel blockers (CCBs) in human plasma. For this approach, samples were treated with 1 mL of acetonitrile, 350 mg of magnesium sulfate, and 70 mg of PSA adsorbent prior to centrifugation. Supernatants then underwent gradient elution for 8 min with an Agilent C18 column using an acetonitrile-water solution supplemented with 5 mmol⋅L^-1 of ammonium acetate. This technique exhibited a good linear response in the 1-800 ng⋅mL^-1 range for the analyzed drugs, with an R²≥ 0.9921, an accuracy of 87.54-113.05%, a matrix effect (ME) of 91.21-116.39%, a precision of 0.19-11.64%, and stability of no more than 10.05%. This time-saving QuEChERS reagent-based pretreatment technique thus allowed for the simultaneous and accurate detection of five CCBs in human plasma samples, providing a promising new basis for therapeutic drug monitoring in patients with hypertension.

Hämoperfusion und Plasmapherese auf der Intensivstation

Neben Nierenersatzverfahren werden auf der Intensivstation mehrere andere extrakorporale Verfahren eingesetzt. In den 1970er- bis 2000er-Jahren stand die Hämoperfusion mit Aktivkohlekapseln zur Entfernung von Toxinen im Vordergrund. Dies ist mittlerweile aufgrund der effektiven Dialyseverfahren, die im Vergiftungsfall auch stark proteingebundene Toxine entfernen, fast bedeutungslos geworden. Vor 10 Jahren erlebte ein Zytokinadsorber die Markteinführung, der darauf gerichtet ist, den „Zytokinsturm“ zu überstehen. Dieser erfreut sich trotz ernüchternder Daten aus prospektiven, randomisierten, kontrollierten Studien wachsender Beliebtheit. Ein gänzlich anderes Therapiekonzept ist der biomimetische Pathogenadsorber, der Bakterien, Viren und Pilze durch Bindung an immobilisiertes Heparin aus dem Blutstrom entfernt. Ob sich diese schnelle Reduktion der Pathogenlast in eine Verbesserung klinisch relevanter Endpunkte übersetzt, ist unklar, da hier prospektive, randomisierte und kontrollierte Studien gänzlich fehlen. Für ein sehr altes Verfahren, nämlich die Plasmapherese, werden wir für die Frühphase der Sepsis bis zum Jahr 2025/2026 Ergebnisse aus 2 großen randomisierten, kontrollierten Studien aus Europa und Kanada erhalten. Neben der Entfernung von Zytokinen erhofft man sich durch die Verwendung von Frischplasma als Austauschflüssigkeit auch das Wiederauffüllen reduzierter protektiver Faktoren wie Angiopoietin 1, ADAMTS13 („a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13“) und Protein C. Alle genannten Verfahren funktionieren nicht nur unterschiedlich, sondern werden auch zu unterschiedlichen Zeitpunkten der Blutstrominfektion/Sepsis eingesetzt.

Calcium Channel Blocker Toxicity: A Practical Approach

Calcium channel blockers (CCBs) are widely prescribed medications for various clinical indications in adults and children. They are available in both immediate and long-acting formulations and are generally classified into dihydropyridines and nondihydropyridines, with nondihydropyridines having more cardioselectivity. CCB toxicity is common given the widespread use which leads to serious adverse clinical outcomes, especially in children. Severe CCB toxicities may present with life-threatening bradycardia, hypotension, hyperglycemia, and renal insufficiency. Dihydropyridine toxicity, however, may present with reflex tachycardia instead of bradycardia. Initial patient evaluation and assessment are crucial to identify the severity of CCB toxicity and design the best management strategy. There are different strategies to overcome CCB toxicity that requires precise dosing and close monitoring in various patient populations. These strategies may include large volumes of IV fluids, calcium salts, high insulin euglycemia therapy (HIET), and vasopressors. We hereby summarize the evidence behind the management of CCB toxicity and present a practical guide for clinicians to overcome this common drug toxicity.

Extracorporeal Treatment for Methotrexate Poisoning: Systematic Review and Recommendations from the EXTRIP Workgroup

Methotrexate is used in the treatment of many malignancies, rheumatological diseases, and inflammatory bowel disease. Toxicity from use is associated with severe morbidity and mortality. Rescue treatments include intravenous hydration, folinic acid, and, in some centers, glucarpidase. We conducted systematic reviews of the literature following published EXtracorporeal TReatments In Poisoning (EXTRIP) methods to determine the utility of extracorporeal treatments in the management of methotrexate toxicity. The quality of the evidence and the strength of recommendations (either "strong" or "weak/conditional") were graded according to the GRADE approach. A formal voting process using a modified Delphi method assessed the level of agreement between panelists on the final recommendations. A total of 92 articles met inclusion criteria. Toxicokinetic data were available on 90 patients (89 with impaired kidney function). Methotrexate was considered to be moderately dialyzable by intermittent hemodialysis. Data were available for clinical analysis on 109 patients (high-dose methotrexate [>0.5 g/m2]: 91 patients; low-dose [≤0.5 g/m2]: 18). Overall mortality in these publications was 19.5% and 26.7% in those with high-dose and low-dose methotrexate-related toxicity, respectively. Although one observational study reported lower mortality in patients treated with glucarpidase compared with those treated with hemodialysis, there were important limitations in the study. For patients with severe methotrexate toxicity receiving standard care, the EXTRIP workgroup: (1) suggested against extracorporeal treatments when glucarpidase is not administered; (2) recommended against extracorporeal treatments when glucarpidase is administered; and (3) recommended against extracorporeal treatments instead of administering glucarpidase. The quality of evidence for these recommendations was very low. Rationales for these recommendations included: (1) extracorporeal treatments mainly remove drugs in the intravascular compartment, whereas methotrexate rapidly distributes into cells; (2) extracorporeal treatments remove folinic acid; (3) in rare cases where fast removal of methotrexate is required, glucarpidase will outperform any extracorporeal treatment; and (4) extracorporeal treatments do not appear to reduce the incidence and magnitude of methotrexate toxicity.

Single-Pass Albumin Dialysis as Rescue Therapy for Pediatric Calcium Channel Blocker Overdose

Calcium channel blocker ingestions remain one of the leading causes of death related to cardiovascular medication ingestion in both adults and pediatric patients. We report a case of a 17-year-old, 103 kg female presenting after an intentional polypharmacy ingestion, including 500 to 550 mg of amlodipine. She presented with profound vasoplegia and cardiovascular collapse requiring high-dose inotropes and eventual life support with extracorporeal membrane oxygenation (ECMO). Current available treatments, designed for adults, including lipid emulsion and methylene blue, provided no sustained clinical improvement. This resulted in the initiation of single-pass albumin dialysis (SPAD). We aim to describe the clinical implications, amlodipine toxic dose effects, and clinical challenges associated with large pediatric patients and high-dose medications. We also discuss several challenges encountered related to dosing and concentration of medications, which led to fluid overload. Given the ongoing obesity epidemic, we routinely see pediatric patients of adult size. This will continue to challenge pediatric use of adult dosing and concentrations to avoid excessive fluid administration for high-dose medications, such as insulin and vasoactive agents. To our knowledge, this is the first successful case of using SPAD in conjunction with ECMO for salvage therapy after refractory life-threatening calcium channel blocker toxicity.

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.

Hemodynamic impact of molecular adsorbent recirculating system in refractory vasoplegic shock due to calcium channel blocker poisoning

OBJECTIVE

To report the hemodynamic effect of to the molecular adsorbent recirculating system (MARS™) therapy for patients in refractory vasoplegic shock due to calcium channel blocker (CCB) poisoning.

METHODS

We report a retrospective cohort of patients who were hospitalized for CCB poisoning with refractory vasoplegic shock and treated by MARS therapy, at Amiens Hospital University, from January 2010 to December 2019. Improvement in hemodynamic was assessed by dynamic changes in mean arterial pressure (MAP) and norepinephrine levels over a 24-h period after MARS therapy. Cardiac function was assessed by transthoracic echocardiography.

RESULTS

MARS therapy was performed on seven patients for CCB poisoning. CCB poisoning included nicardipine (n = 3, 43%) amlodipine (n = 3, 43%), and verapamil (n = 1, 14%). The median time to start MARS therapy was 24 [14-27] h after drug ingestion and 6 [2-9] h after ICU admission. Cardiac output was preserved for all patients. MAP values improved from 56 [43-58] to 65 [61-78] 16 mmHg (p = 0.005). Norepinephrine dose significantly decreased from 3.2 [0.8-10] µg/kg/min to 1.2 [0.1-1.9] µg/kg/min (p = 0.008) and lactate level decreased from 3.2 [2.4-3.4] mmol/l^-1 to 1.6 [0.9-2.2] mmol/l^-1 (p = 0.008). The median length of ICU stay was 4 (2-7) days and hospital stay was 4 (4-16) days. No complication related to the MARS therapy were reported. No patient died and all were discharged from the hospital.

CONCLUSION

We reported the largest case-series of MARS therapy for refractory vasoplegic shock due to CCB poisoning. We observed that MARS therapy was associated with an improvement of hemodynamic parameters.