Researchers are warning cancer survivors against taking Western and Chinese medicine simultaneously without consulting their doctors, as it could cause unexpected interactions.
The Chinese University's faculty of medicine found that half of childhood cancer survivors in a survey reported using complementary and alternative medicine. Of these, one third risked seeing moderate impacts.
Some of the complementary and alternative therapies used included traditional Chinese medicine, acupuncture and natural supplements like vitamins and fish oil.
More than 36 percent of the childhood cancer respondents said they had used more than one type of alternative therapy, with the most common combination being Chinese medicine and natural supplements.
In a study of 69 patients who had used alternative therapy and prescription medications concurrently, researchers found that 30.4 percent of recovered patients were at risk of drug-and-herb interactions of moderate significance.
For example, the concurrent use of fish oil and warfarin - a type of blood thinner - may increase patients' bleeding risk, while the Chinese herb Angelica sinensis - or dong quai - may interfere with the effects of estrogen replacement therapy.
"Dietary therapies and traditional Chinese health exercises are generally safe most of the time. But the inappropriate use of herbs or herbal medicines can lead to harmful effects," said Katy Koon Ho-kee, an assistant lecturer at the school of Chinese medicine.
Researchers, however, pointed out that not all interactions between herbs and drugs were harmful, and interdisciplinary collaboration was needed to provide the best treatment option for cancer patients.
"We encourage patients to have an open discussion with their health-care providers regarding the use of complementary and alternative medicine, especially cancer survivors who are taking long-term medication," said the principal investigator of the study, assistant professor Cheung Yin-ting from the school of pharmacy.
Funded by the government's Chinese Medicine Development Fund, a CUHK multidisciplinary team has launched an education program to promote the safe and effective use of traditional Chinese medicine in childhood cancer survivors.
The program includes online seminars as well as educational materials - which will be available by next month - to guide patients and caregivers in the use of complementary and alternative medicine.