Dr. Ugur Turk, from Central Hospital, Izmir, Turkey, reports on the cases of a 68 year old father and 27 year old son who were both admitted to the Izmir emergency department at the same time with symptoms of vomiting and dizziness. Surface ECGs revealed both patients to have complete atrioventricular block and atrial flutter with slow ventricular responses.
When a history was taken both father and son reported that their breakfasts over the past three mornings had included high amounts of honey from the Black sea region of Turkey. This information immediately triggered Turk and colleagues to consider that their patients could be suffering from 'mad honey poisoning'.
Mad honey poisoning occurs after people consume honey contaminated with grayanotoxin, a chemical contained in nectar from the Rhododendron species ponticum and luteum. Grayanotoxin is a neurotoxin that binds to the sodium channels in the cell membrane, maintaining them in an open state and prolonging depolarisation.
"It's like the effect of cholingeric agents, and results in stimulation of the unmyelinated afferent cardiac branches of the vagus nerve which leads to a tonic inhibition of central vasomotor centres with a reduced sympathetic output and a reduced peripheral vascular resistance,"says Dr. Turk, "This in turn triggers the cardioinhibitory Berzold-Jarisch reflex which leads to bradycardia, continued hypotension, and peripheral vasodilatation."
Mad honey poisoning generally lasts no more than 24 hours, with symptoms of the mild form including dizziness, weakness, nausea, vomiting, excessive perspiration, hypersalivation and paraesthesia. Symptoms of the more severe form include syncope, seizures, complete atrioventricular block and even fatal tachyarrhythmias (due to oscillatory after potentials).
While no specific antidote exists for grayanotoxin poisoning mild cases can be treated with atropine and selective M2 muscarinic receptor antagonists; while for the more severe form treatment options include temporary pacemaker implantation, and vasopressor agents.
Heh. Maybe that explains why the "honey badger don't care." Especially since the testing of the honey consumed by the two individuals only tested for the presence of Rhododendrons and not grayanotoxin.