Safety evaluation of Elixir Paregorico in healthy volunteers: a phase I study

A liquid alcoholic extract of Papaver somniferum named Elixir Paregorico is extensively used for diarrheal diseases in Brazil. Its increased popularity has brought concerns and fears over the safety of this herbal product. Given the lack of investigative clinical studies, in this regard, this study investigated whether Elixir Paregorico administration causes any noticeable toxic effects in healthy volunteers. In all, 28 middle-aged healthy male (n = 14) and female (n = 14) were enrolled. After screening and a washout period, eligible subjects received four oral doses per day of Elixir Paregorico (3 mL diluted in 30 mL of water) over a 10-day period. Altogether, all 28 participants completed the study. The results of hematological and biochemical tests performed pre and post-treatment were within the normal range. In both male and female volunteers, there were no statistical differences (P > 0.05) in the results of clinical and laboratory tests performed at screening, on 5th and 10th day visits, and at final assessment. Although mild adverse events were related, which subsided spontaneously, no serious untoward reactions were reported following Elixir Paregorico administration. To our knowledge, this is the first demonstration that Elixir Paregorico administered four times a day for 10 days is safe and does not cause any noticeable toxic effect in healthy volunteers.