Adverse reactions of liquorice consumed in the diet: a 10-year retrospective study of poison centres in France.

Introduction: We aimed to describe the symptoms, patient demographics, and trends over time of adverse effects related to liquorice consumed in the diet reported to French poison centres.

Methods: We performed a retrospective study of data from French poison centres of cases of adverse effects of liquorice consumed in the diet, with a high causality score, between 2012 and 2021 (10 years).

Results: Sixty-four cases were included. The annual number of cases ranged from three to nine, with no significant variation over the study period. Liquorice-induced reactions were very rare (0.008% of all cases with symptoms reported to French poison centres). The products consumed were non-alcoholic beverages (non-alcoholic pastis, liquorice-based Antésite^®, and liquorice syrup), alcoholic beverages of the pastis type (10.9%), confectionery containing liquorice (12.5%), confectionery made with liquorice extract only (9.4%), herbal teas (12.5%) and food supplements (4.7%). Consumption was commonly chronic (67.2%) and non-compliant (70.3%). Chronic users presented with symptoms suggestive of pseudohyperaldosteronism, the severity of which seemed to correlate with the amount of glycyrrhizin ingested. Severity was high in 43.8% of cases. When the outcome was known (56.3%), it was favourable in almost all cases (94.4%), often after inpatient care, particularly in an intensive care unit. One patient had sequelae due to a stroke, and one fatality was reported. Severe cases were observed with all types of products, except liquorice syrup and food supplements, and more frequently with beverages (pastis with or without alcohol, and Antésite^®).

Discussion: Due to significant variability in response to glycyrrhizin, some patients presented signs and symptoms suggestive of pseudohyperaldosteronism such as hypokalaemia, salt and water retention, and hypertension despite consuming the product as directed.

Conclusions: Liquorice-induced effects were rarely reported to French poison centres, but their severity was high. Most patients were adults with chronic and non-compliant consumption, especially of soft drinks, with a clinical presentation suggestive of pseudohyperaldosteronism.