Successful treatment with enoximone for severe poisoning with atenolol and verapamil: a case report

Extracorporeal Life Support in Severe Propranolol and Verapamil Intoxication

Combined poisoning with calcium-channel blockers and β-blockers is usually associated with severe heart failure. This report shows the effectiveness of emergency extracorporeal life support in treating life-threatening simultaneous propranolol and verapamil intoxication. A 15-year-old girl presented in cardiogenic shock after alcohol consumption and a propranolol and verapamil overdose; plasma concentrations: propranolol, 0.53 m/mL; verapamil, 1.06 mg/mL. She was successfully resuscitated with extracorporeal life support. Therapeutic plasma exchange was initiated. Extracorporeal support was discontinued 70 hours later. The patient made a full recovery. Simultaneous verapamil and propranolol overdoses can cause severe hemodynamic compromise and arrest of electrical and mechanical function of the heart. Emergency extracorporeal life support can successfully maintain vital organ blood flow and allows time for drug metabolism, redistribution, and removal. Therapeutic plasma exchange may reduce the time of emergency extracorporeal life support. Emergency extracorporeal life support should be considered early in cases of near-fatal intoxications with cardiodepressive drugs.

Calcium channel antagonist and beta-blocker overdose: antidotes and adjunct therapies

Management of cardiovascular instability resulting from calcium channel antagonist (CCB) or beta-adrenergic receptor antagonist (BB) poisoning follows similar principles. Significant myocardial depression, bradycardia and hypotension result in both cases. CCBs can also produce vasodilatory shock. Additionally, CCBs, such as verapamil and diltiazem, are commonly ingested in sustained-release formulations. This can also be the case for some BBs. Peak toxicity can be delayed by several hours. Provision of early gastrointestinal decontamination with activated charcoal and whole-bowel irrigation might mitigate this. Treatment of shock requires a multimodal approach to inotropic therapy that can be guided by echocardiographic or invasive haemodynamic assessment of myocardial function. High-dose insulin euglycaemia is commonly recommended as a first-line treatment in these poisonings, to improve myocardial contractility, and should be instituted early when myocardial dysfunction is suspected. Catecholamine infusions are complementary to this therapy for both inotropic and chronotropic support. Catecholamine vasopressors and vasopressin are used in the treatment of vasodilatory shock. Optimizing serum calcium concentration can confer some benefit to improving myocardial function and vascular tone after CCB poisoning. High-dose glucagon infusions have provided moderate chronotropic and inotropic benefits in BB poisoning. Phosphodiesterase inhibitors and levosimendan have positive inotropic effects but also produce peripheral vasodilation, which can limit blood pressure improvement. In cases of severe cardiogenic shock and/or cardiac arrest post-poisoning, extracorporeal cardiac assist devices have resulted in successful recovery. Other treatments used in refractory hypotension include intravenous lipid emulsion for lipophilic CCB and BB poisoning and methylene blue for refractory vasodilatory shock.

Treatment for calcium channel blocker poisoning: a systematic review

CONTEXT

Calcium channel blocker poisoning is a common and sometimes life-threatening ingestion.

OBJECTIVE

To evaluate the reported effects of treatments for calcium channel blocker poisoning. The primary outcomes of interest were mortality and hemodynamic parameters. The secondary outcomes included length of stay in hospital, length of stay in intensive care unit, duration of vasopressor use, functional outcomes, and serum calcium channel blocker concentrations.

METHODS

Medline/Ovid, PubMed, EMBASE, Cochrane Library, TOXLINE, International pharmaceutical abstracts, Google Scholar, and the gray literature up to December 31, 2013 were searched without time restriction to identify all types of studies that examined effects of various treatments for calcium channel blocker poisoning for the outcomes of interest. The search strategy included the following Keywords: [calcium channel blockers OR calcium channel antagonist OR calcium channel blocking agent OR (amlodipine or bencyclane or bepridil or cinnarizine or felodipine or fendiline or flunarizine or gallopamil or isradipine or lidoflazine or mibefradil or nicardipine or nifedipine or nimodipine or nisoldipine or nitrendipine or prenylamine or verapamil or diltiazem)] AND [overdose OR medication errors OR poisoning OR intoxication OR toxicity OR adverse effect]. Two reviewers independently selected studies and a group of reviewers abstracted all relevant data using a pilot-tested form. A second group analyzed the risk of bias and overall quality using the STROBE (STrengthening the Reporting of OBservational studies in Epidemiology) checklist and the Thomas tool for observational studies, the Institute of Health Economics tool for Quality of Case Series, the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines, and the modified NRCNA (National Research Council for the National Academies) list for animal studies. Qualitative synthesis was used to summarize the evidence. Of 15,577 citations identified in the initial search, 216 were selected for analysis, including 117 case reports. The kappa on the quality analysis tools was greater than 0.80 for all study types.

RESULTS

The only observational study in humans examined high-dose insulin and extracorporeal life support. The risk of bias across studies was high for all interventions and moderate to high for extracorporeal life support. High-dose insulin. High-dose insulin (bolus of 1 unit/kg followed by an infusion of 0.5-2.0 units/kg/h) was associated with improved hemodynamic parameters and lower mortality, at the risks of hypoglycemia and hypokalemia (low quality of evidence). Extracorporeal life support. Extracorporeal life support was associated with improved survival in patients with severe shock or cardiac arrest at the cost of limb ischemia, thrombosis, and bleeding (low quality of evidence). Calcium, dopamine, and norepinephrine. These agents improved hemodynamic parameters and survival without documented severe side effects (very low quality of evidence). 4-Aminopyridine. Use of 4-aminopyridine was associated with improved hemodynamic parameters and survival in animal studies, at the risk of seizures. Lipid emulsion therapy. Lipid emulsion was associated with improved hemodynamic parameters and survival in animal models of intravenous verapamil poisoning, but not in models of oral verapamil poisoning. Other studies. Studies on decontamination, atropine, glucagon, pacemakers, levosimendan, and plasma exchange reported variable results, and the methodologies used limit their interpretation. No trial was documented in humans poisoned with calcium channel blockers for Bay K8644, CGP 28932, digoxin, cyclodextrin, liposomes, bicarbonate, carnitine, fructose 1,6-diphosphate, PK 11195, or triiodothyronine. Case reports were only found for charcoal hemoperfusion, dialysis, intra-aortic balloon pump, Impella device and methylene blue.

CONCLUSIONS

The treatment for calcium channel blocker poisoning is supported by low-quality evidence drawn from a heterogeneous and heavily biased literature. High-dose insulin and extracorporeal life support were the interventions supported by the strongest evidence, although the evidence is of low quality.

Case report: atenolol overdose successfully treated with hemodialysis

Owing to the drug's favorable hydrophilic and pharmacokinetic characteristics, a number of case reports have demonstrated effective treatment of atenolol overdose with hemodialysis. However, the efficiency of atenolol clearance throughout hemodialysis treatments has not previously been examined. In this report, a patient with impaired renal function was successfully treated with two 5-hour intermittent high-flux high-efficiency hemodialysis therapies after atenolol overdose. Serial atenolol levels were measured during his hemodialysis treatments. We observed an over 50% plasma atenolol concentration reduction after each 5-hour hemodialysis therapy. Hemodialysis therapy is an effective treatment for atenolol overdose, especially in patients with impaired renal function.

Prolonged Refractory Hypotension following Combined Amlodipine and Losartan Ingestion Responsive to Metaraminol

Introduction. Overdose with the calcium channel blocker amlodipine can cause profound hypotension that may be exacerbated by the concurrent ingestion of an angiotensin II receptor antagonist. Best management of such overdoses is uncertain although the use of hyperinsulinaemia-euglycaemia (HIE) has been recommended. Case report. We report a case of mixed amlodipine and losartan overdose in a 50-year-old lady. Severe hypotension was resistant to conventional vasopressors and high-dose insulin/euglycaemia, but did respond to a metaraminol infusion. Conclusion. A trial of metaraminol early in severe cases of calcium channel blocker and angiotensin II receptor antagonist toxicity may be of benefit, especially when conventional ionotropic treatment measures are failing.

Levosimendan as a rescue drug in experimental propranolol-induced myocardial depression: a randomized study

STUDY OBJECTIVE

Severe beta-blocker intoxication remains a clinical challenge despite a variety of treatment options. Because of its unique mechanism of action, the new calcium sensitizer levosimendan may provide more prominent cardiac support compared with current medications used to reverse negative inotropy. We hypothesize that levosimendan could reverse propranolol-induced severe negative inotropy in a porcine model of beta-blocker intoxication.

METHODS

Twenty-four pigs were anesthetized and monitored. After severe propranolol intoxication was completed, animals were randomized into 3 groups. With a double-blind procedure, 9 animals received a 1.25-mg levosimendan bolus, followed by saline solution infusion, 9 animals received mean arterial pressure-targeted dobutamine infusion after saline solution bolus, and 6 animals received a saline solution bolus followed by saline solution infusion. Hemodynamic and laboratory data were collected during a follow-up period of 120 minutes.

RESULTS

All 9 pigs in the levosimendan group survived. In contrast, 4 of 6 (67%) and 7 of 9 (78%) pigs died during the experiment in the placebo and the dobutamine groups, respectively. The levosimendan group showed improved change in the maximum positive slope of the left ventricular pressure, cardiac output, stroke volume, and mean arterial pressure compared with the dobutamine and the placebo groups.

CONCLUSION

Levosimendan improved hemodynamic function and survival in this animal model of severe propranolol intoxication. The potential clinical application of levosimendan in propranolol intoxication warrants further investigation.

Enoximone in cardiac arrest caused by propranolol: two case reports

We report two clinical cases of cardiac arrest, the former due to an adverse effect of intravenous (i.v.) propranolol in a patient with systemic sclerosis, the latter from a propranolol suicidal overdose. In both cases, conventional advanced life support (ALS) was ineffective but both patients eventually responded to the administration of enoximone, a phosphodiesterase III (PDE III) inhibitor. After the arrest, both patients regained consciousness and were discharged home. The chronotropic and inotropic effects of PDE III inhibitors are due to inhibition of intracellular PDEIII and are therefore unaffected by beta-blockers. These cases suggest that PDEIII inhibitors may be useful in restoring spontaneous circulation in cardiac arrest associated with beta-blocker administration when standard ALS is ineffective.

Bench-to-bedside review: hyperinsulinaemia/euglycaemia therapy in the management of overdose of calcium-channel blockers

Hyperinsulinaemia/euglycaemia therapy (HIET) consists of the infusion of high-dose regular insulin (usually 0.5 to 1 IU/kg per hour) combined with glucose to maintain euglycaemia. HIET has been proposed as an adjunctive approach in the management of overdose of calcium-channel blockers (CCBs). Indeed, experimental data and clinical experience, although limited, suggest that it could be superior to conventional pharmacological treatments including calcium salts, adrenaline (epinephrine) or glucagon. This paper reviews the patho-physiological principles underlying HIET. Insulin administration seems to allow the switch of the cell metabolism from fatty acids to carbohydrates that is required in stress conditions, especially in the myocardium and vascular smooth muscle, resulting in an improvement in cardiac contractility and restored peripheral resistances. Studies in experimental verapamil poisoning in dogs have shown that HIET significantly improves metabolism, haemodynamics and survival in comparison with conventional therapies. Clinical experience currently consists only of a few isolated cases or short series in which the administration of HIET substantially improved cardiovascular conditions in life-threatening CCB poisonings, allowing the progressive discontinuation of vasoactive agents. While we await further well-designed clinical trials, some rational recommendations are made about the use of HIET in severe CBB overdose. Although the mechanism of action is less well understood in this condition, some experimental data suggesting a potential benefit of HIET in β-adrenergic blocker toxicity are discussed; clinical data are currently lacking.

Severe poisoning with sotalol and verapamil. Recovery after 4 h of normothermic CPR followed by extra corporeal heart lung assist

In acute poisoning with beta-blocking drugs and calcium-channel blockers patients may present with serious symptoms. We present a case of life-threatening sotalol and verapamil intoxication in a 29-year-old female suffering from depression. She was admitted to our hospital a few hours after she had taken 3.6 g verapamil and 4.8 g sotalol. On being found the patient was breathing and had a palpable pulse. On admission the patient experienced a cardiovascular collapse and CPR was started. Echocardiography confirmed cardiac standstill. After 4 h of normothermic CPR, extra corporeal heart lung assist (ECHLA) was established. Vasoactive drugs could be stopped after 2 days with ECHLA, and after 5 days the patient was extubated. The patient experienced several complications (intestinal bleeding, transient nerve paralysis, and renal failure due to rhabdomyolysis) but made a complete recovery and started working 6 months after the poisoning. She was no longer depressed.