Lupin beans are the yellow legume seeds of the genus
Lupin or lupini beans are the yellow legume seeds of the genus
A previously healthy, 12-year-old boy weighing 50 kg visited the emergency department for ongoing generalized tonic-clonic seizure and vomiting. These manifestations occurred 30 minutes after eating 2 handfuls (approximately 300 mg) of raw lupin beans. The initial vital signs were as follows: blood pressure, 150/110 mmHg; heart rate, 151 beats per minute; respiratory rate, 32 breaths per minute; temperature, 36.5°C; oxygen saturation, 99% on room air; and a Glasgow Coma Scale of 12. Because he was considered to be in status epilepticus, intravenous midazolam (0.1 mg/kg) was administered, and intubation was performed to protect the airway. The physical examination showed bilateral mydriasis with weak light reflexes, increased muscles tone, flushing, piloerection, and dry oral mucosa. Deep tendon reflexes were normal, but bilateral Babinski reflexes were observed. Capillary refill time was shorter than 2 seconds. No abnormal findings in the chest and abdomen were found. Laboratory findings were unremarkable. The cranial computed tomography showed normal findings. After 6 hours of the ingestion, he was transferred to the intensive care unit (ICU).
In the ICU, sinus tachycardia and hypertension were sustained for the first 24 hours. His echocardiogram was normal. The tachycardia resolved gradually and spontaneously within 24 hours. The electroencephalographic finding suggested diffuse encephalopathy. Midazolam and fentanyl infusion were continued to maintain the patient-ventilator synchrony with daily interruption. No clinical and electroencephalographic seizures were observed in the ICU while receiving midazolam infusion (0.1 mg/kg/hour). On day 3, the boy underwent extubation. During the hospitalization, he underwent only supportive care. On day 5, the Glasgow Coma Scale became 14, and he was transferred to the general ward. Later, the ingested beans were turned out to be farm products of the boy’s relatives.
Although lupin beans have been generally used for animal feed, medical research has recently shown that eating lupins can provide benefits for human health[
Quinolizidine alkaloids are found in various species of the genus
Alkaloid-rich lupin beans inhibit the excitatory neurotransmission via the nicotinic acetylcholine receptors and also act as muscarinic antagonists. Quinolizidine alkaloids with high affinities to the nicotinic receptors have a lower affinity to the muscarinic receptors. Lupanine, lupinine, and sparteine are listed as the main alkaloids in seeds of the genus
In our case, the anticholinergic toxidrome was suggested by the manifestations along with tachycardia and hypertension. At that time, it was unknown about the chemical composition and botanical origin. Thus, it was challenging to associate the manifestations with the ingested doses or a specific alkaloid. Lupanine may be the chief cause of anticholinergic effects[
The proper consumption of lupin seeds requires the removal of toxic alkaloids. The process for debittering and cleaning the impurities are listed in the order of sequence: soaking for 1 day, cooking in water for 1 hour, and placing in containers and exposing to running water for 4-5 days[
In children, acute anticholinergic toxidrome is uncommon. This toxidrome generally develops after exposure to various drugs, including some antihistamines, antipsychotics, antispasmodics, and antidepressants, as well as ingestion of some mushrooms and plants[
The half-life of the alkaloid is 6 hours, and it is usually cleared within the next 24 hours due to the rapid urinary excretion[
Only few pediatric cases have been reported with lupin bean intoxication. Daverio et al.[
Lupin beans are consumed worldwide for their protein contents. Acute anticholinergic toxidrome is caused by rich quinolizidine alkaloids. Therefore, lupin bean intoxication should be considered if children have anticholinergic toxidrome.
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