I was interested to read the best BET “Glucagon for the treatment of symptomatic β blocker overdose” by Boyd and Ghosh.¹ As the authors recognised, the six studies tabulated were of mixed overdose or had multiple therapeutic interventions and could not answer the question posed. However, had the search strategy included individual drug names (for example, propranolol, atenolol) more relevant papers would have been found, including two cases of pure β blocker overdose successfully treated with glucagon alone.^2,3 The evidence for glucagon in treating symptomatic β blocker overdose will probably never reach a higher level than case reports. This is true of most “antidotes” because of ethical constraints on toxicology studies. Glucagon, however, has been shown to be effective in treating symptomatic β blocker overdose in various controlled animal studies.

About 20 deaths per year in the UK are attributed to β blocker overdose. The authors state that glucagon is expensive. It is true that large doses may be required and that this may outstrip hospital supplies. However, at an initial dose of 5–10 mg (100 μg/kg) intravenously at £19.95/mg, the cost⁴ compares favourably with thrombolysis as a potential lifesaving intervention. Atropine has been shown to be spectacularly ineffective in this setting and alternatives such as β agonists, phospho-diesterase inhibitors, insulin-euglycaemia, and pacing have significantly more associated complications than glucagon without improving outcome.

Glucagon treatment for symptomatic β blocker overdose should not yet be discarded on grounds of cost or lack of evidence.