Successful treatment of severe atenolol overdose with calcium chloride

Massive metoprolol overdose requiring ECMO: brief review of the evidence behind recommended treatments

A man in his late 60s developed shock after ingesting 7500 mg of metoprolol tartrate that was refractory to all medical treatment including hyperinsulinaemic euglycaemia, intravenous lipid emulsion and dialysis, eventually needing rescue extracorporeal membrane oxygenation. A brief review of the recommended treatments in beta-blocker overdose is therefore warranted.

Amlodipine poisoning revisited: Acidosis, acute kidney injury and acute respiratory distress syndrome

We report the case of an 18-year-old girl presenting with shock following ingestion of 85 mg of amlodipine and 850 mg of atenolol with suicidal intent. Subsequently, the patient developed severe metabolic acidosis, acute kidney injury, and acute respiratory distress syndrome, which were managed conservatively. The patient ultimately made a full recovery. Given the popularity of amlodipine and atenolol as antihypertensive drugs in this part of the world, it is likely that more such cases will be encountered in the future. Physicians should be aware of the severe complications that can develop with amlodipine overdose.

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.

Intravenous lipid emulsion does not augment blood pressure recovery in a rabbit model of metoprolol toxicity

Intravenous lipid emulsion (ILE) has been demonstrated to be an effective treatment for systemic toxicity associated with local anaesthetics and increasingly non-local anaesthetic agents of high lipophilicity. Effect for ILE has been demonstrated in animal models of propranolol poisoning; however, any benefit for ILE in more hydrophilic β-blockers remains uncertain. We determined to examine the effect of ILE on haemodynamic recovery following induction of hypotension with the relatively hydrophilic β-blocker, metoprolol. Twenty sedated, invasively monitored and mechanically ventilated adult New Zealand white rabbits underwent metoprolol infusion to mean arterial pressure (MAP) 60% baseline. Intravenous rescue was given according to the following groups: 6 mL/kg 20% lipid emulsion or 6 mL/kg 0.9% saline solution over 4 min. Haemodynamic parameters were obtained in 15 min. MAP was 70 (interquartile range (IQR), 58-82) mmHg saline group and 79 (IQR, 72-89) mmHg ILE group at baseline, and 38 (IQR, 33-40) mmHg saline group and 41 (IQR, 40-43) mmHg ILE group, respectively, following metoprolol infusion. No statistically significant difference between ILE and saline-treated groups was observed in MAP, or pulse rate, at any time point following rescue therapy. ILE was not effective in reversal of metoprolol-induced hypotension in this rabbit model. These findings lend inferential support for the 'lipid sink' as principal mechanism for the beneficial effect observed with ILE administration in other models of lipophilic β-blocker-induced toxicity.

Multiple cardiac arrhythmias in a previously healthy child: a case of accidental digitalis intoxication?

We present a case of multiple arrhythmias in a 3-year-old child who was presented to the emergency department with emesis. Initial vital signs were significant for a heart rate from 40 to 60 beats per minute with stable blood pressure. An electrocardiogram showed complete atrioventricular block with a junctional escape rhythm of 40 to 55 bpm that subsequently progressed to atrial flutter/fibrillation and then to a junctional escape rhythm. She was given intravenous atropine, resulting in acceleration of the junctional rhythm. Sinus rhythm resumed with a prolonged PR interval a few hours later with normalization of the electrocardiogram the following day. Routine laboratory tests, toxicology screens, and tests for other cardiac medications in the home were negative. However, at 20 hours after presentation, her digoxin level was 2.9 ng/mL. Parents denied that the child had access to any digoxin-containing substances. This case illustrates that digoxin toxicity can manifest with multiple arrhythmias and that recognition of this can be very difficult, especially when there is no witness to ingestion. Clinicians should be suspicious for digoxin toxicity when a child presents with persistent emesis, altered level of consciousness, and bradyarrhythmias with or without hemodynamic instability.