Hypotension and Bradycardia Caused by the Inadvertent Ingestion of <i>Rhododendron japonicum</i>

Abstract

A 61-year-old man was transferred to our hospital with the complaints of dizziness, severe nausea and abdominal discomfort after consuming approximately 50 g of the flowers of Rhododendron japonicum. On admission, hypotension and sinus bradycardia were evident. Symptoms including hypotension and bradycardia completely recovered within 12 hours following normal saline infusion and intravenous atropine. The ingestion of certain types of Rhododendron species can cause intoxication, referred to as "mad honey poisoning", due to the action of grayanotoxins. This is the first local case of acute intoxication caused by Rhododendron japonicum.

Risks for human health related to the presence of grayanotoxins in certain honey

“…The occurrence of grayananes in foods other than honey derived from certain Ericaceae plants has also led to human cases of intoxications. The same characteristic symptoms as for Rhododendron honey intoxications have been described from the consumption of Rhododendron liqueur (Choi et al., 2017), of herbal teas prepared from Pieris japonica (Aleguas et al., 2008) or the leaves of Agarista salicifolia (Martinet et al., 2005) or from the consumption of blossoms of R. japonicum (Koda et al., 2016) or R. mucronulatum (Lee et al., 2007) due to misinformation on their edibility. However, none of these publications allows an estimate of the dose of grayananes ingested.…”