Case of levodopa toxicity from ingestion of Mucuna gigantea

Hawai'i is home to 1000 native species of flowering plants. Mucuna gigantea is one such Hawaiian species which has been studied as affordable sustenance and as a cover crop in developing countries. Mucuna gigantea and other Mucuna species (spp.) in general, are known to contain natural levodopa and its utility in the treatment of Parkinson's Disease has also been evaluated. Levodopa is converted in the periphery into dopamine which can then act on dopamine receptors to cause nausea, vomiting, arrhythmias, and hypotension. We describe a case in which a patient presents with abdominal pain, nausea, and vomiting after legume ingestion. The bean was ultimately identified as Mucuna gigantea and the patient was diagnosed with levodopa-induced gastrointestinal toxicity from consumption of the legume. A literature review was conducted using the database search engines, Biological Abstracts and PubMed, with a broad combination of keywords of which include "mucuna, "gigantean," "levodopa," "l-dopa," "toxicity," and the association between Mucuna gigantea ingestion and levodopa toxicity is discussed. These findings expand the differential diagnosis of abdominal pain associated with nausea and vomiting in the correct clinical context.