Management of Calcium Channel Blocker Toxicity in the Pediatric Patient

Calcium Channel Blocker Overdose Causes Acute Respiratory Distress Syndrome and Acute Kidney Injury in a 15-Year-Old Female

Calcium channel blockers (CCBs) are among the most commonly prescribed cardiovascular medications in the adult population. Approximately 20% of adults with hypertension in the United States are prescribed dihydropyridine calcium channel blockers. Similarly, in the pediatric population, CCBs such as nifedipine and amlodipine are frequently prescribed in the non-emergent management of hypertension in children and adolescents. Despite the prevalence of CCB usage, the available literature on the management of calcium channel blocker toxicity in the pediatric population remains scarce. In the absence of formal guidelines, the management of CCB overdoses comes from case reports. This case identifies a 15-year-old Hispanic female who developed acute respiratory distress syndrome (ARDS) and acute kidney injury (AKI) after an overdose of amlodipine. Our patient presented with profound, refractory hypotension requiring substantial inotropic support. She subsequently developed significant dyspnea, desaturating into the 80s with radiological evidence of ARDS requiring endotracheal intubation. After aggressive diuresis and electrolyte replacement, along with inotropic agents to maintain adequate blood pressure, our patient began to make significant clinical progress. With continued improvement and resolution of her AKI and ARDS, she was successfully weaned off ventilatory support and all infusions. Our patient was deemed medically appropriate for discharge 10 days after the initial presentation and was admitted to an inpatient psychiatric unit. Calcium channel blocker toxicity can pose considerable risks, as was seen with our patient. Prompt recognition and judicious management of CCB overdoses can mitigate associated morbidity and mortality, resulting in favorable outcomes for patients. The intention behind documenting this case is to contribute to the limited literature on the successful management of calcium channel blocker poisoning in the pediatric population.

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.

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 cardiopulmonary resuscitation for the treatment of amlodipine overdose in a pediatric patient

We present the case of a 16-year-old female with systemic lupus erythematosus who presented with shock of unclear etiology, refractory to fluid resuscitation and triple vasopressors. She suffered pulseless electrical activity and underwent cannulation onto veno-arterial extracorporeal membrane oxygenation (ECMO). After cannulation, it was discovered she had intentionally overdosed on her home medication, amlodipine, a calcium channel blocker (CCB). She was supported on ECMO, treated with IV calcium and insulin, and was able to be weaned off ECMO after 4 days. She developed oligoanuric acute kidney injury, treated with continuous renal replacement therapy followed by intermittent hemodialysis. At discharge, she was neurologically intact and did not require dialysis. Herein, we review the treatment of CCB overdose, review the literature on the use of ECMO in refractory shock due to cardiovascular medication overdose, and highlight the utility of ECMO in pediatric refractory shock and/or cardiac arrest of unclear etiology.

N-acetylcysteine prevents verapamil-induced cardiotoxicity with no effect on the noradrenergic arch-associated neurons in zebrafish

There is a strong association between calcium channel blockers (CCBs) and heart failure. CCB toxicity is very common due to overdose and underlying medical conditions. CCBs also have been shown to affect the nervous system. Recently, we demonstrated that the antioxidant N-acetylcysteine (NAC) prevented ketamine-induced cardiotoxicity, developmental toxicity and neurotoxicity. Functionally, we attributed NAC's beneficial effect to its ability to increase cellular calcium. Here, we hypothesized that if there was an involvement of calcium in NAC's preventative effects on ketamine toxicity, NAC might also ameliorate toxicities induced by verapamil, an L-type CCB used to treat hypertension. Using zebrafish embryos, we show that in the absence of NAC, verapamil (up to 100 μM) dose-dependently reduced heart rate and those effects were prevented by NAC co-treatment. Furthermore, a 2-h treatment with NAC rescued reduction of heart rate induced by pre-treatment of 50 and 100 μM of verapamil for 18 h. Verapamil up to 100 μM and NAC up to 1.5 mM did not have any adverse effects on the expression of tyrosine hydroxylase in the noradrenergic neurons of the arch-associated cluster (AAC) located near the heart. NAC did not change cysteine levels in the embryos suggesting that the beneficial effect of NAC on verapamil toxicity may not involve its antioxidant property. In our search for compounds that can prevent CCB toxicity, this study, for the first time, demonstrates protective effects of NAC against verapamil's adverse effects on the heart.