Analysis of adverse event reports associated with complementary health products in Singapore from 2017 to 2023

The use of complementary health products (CHPs), including Chinese Proprietary Medicines (CPMs), health supplements, traditional medicines and homeopathic medicines, has become increasingly prevalent in Singapore's multicultural society. While these products are widely used for maintaining health and treating minor ailments and are generally safe, potential adverse effects have been reported. This study analyzes adverse event reports related to CHPs submitted to Singapore Health Sciences Authority (HSA) from 2017 to 2023.

AE reports involving CHPs assessed by the Vigilance and Compliance Branch (VCB) of HSA from 2017 to 2023 were collated and analyzed. The analysis included patient demographics, AE details, suspected product information, medical history, laboratory results, concomitant therapies, and reporter's profession.

Of the 182,131 AE reports associated with pharmaceutical products and CHPs, 727 reports (0.4%) were associated with CHPs. Health supplements accounted for the highest number of reports (68% of total). "Skin and appendages disorders" were the most commonly reported system organ class, with glucosamine-containing products accounting for the highest number of adverse events. Patients primarily used CHPs for pain relief (33.1%), general health and wellbeing (20.6%), and weight management (8.8%). Products found to contain undeclared illegal substances were most frequently indicated for pain relief. The three most common adulterants were dexamethasone, chlorpheniramine, and prednisolone.

While CHPs are generally safe, adulterated products, especially those from dubious sources, pose real health risks. Healthcare professionals and consumers should remain vigilant about potential adulteration and report suspected CHPs related AEs. Even when causality remains unclear, reporting supports timely regulatory actions when concerning patterns emerge.

This study examined 727 adverse event reports associated with CHPs between 2017 and 2023, accounting for 0.4% of all reported adverse events. Health supplements were the most frequently reported category, with glucosamine-containing products accounting for the highest number of adverse events, predominantly affecting the skin. Products found to contain undeclared illegal substances were most frequently indicated for pain relief, with dexamethasone, chlorpheniramine, and prednisolone being the most common adulterants found. These findings highlight the need for continued vigilance in the monitoring of CHPs to safeguard public health.