Doctors need to discuss herb-drug interaction with patients

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People worldwide have been using herbal products to manage and treat their healthcare problems from before the inception of conventional medicine. 

According to the World Health Organisation, a large proportion — 60 to 80% — of the South African population use herbal products for the treatment of health problems. This can be attributed to this being a diverse country with a population which has different cultural practices. Indigenous knowledge, acquired outside the educational system, and the lived experiences of people also play a role. 

South Africa, with about 30 000 plant species, is rich in indigenous medicinal plants. A significant amount of people still depend on these plants for their primary healthcare needs, especially those with chronic conditions. Many people resort to them out of desperation, for alternative treatment, to reduce the side effects of conventional medicine or because they have had unsatisfactory experiences with the healthcare system. 

Others use herbal products because they think of them as safe as they are “natural” and have been recommended by family or community members.

Herbal products are affordable, according to people who use them. They can be accessed from traditional healers, herbalists, health shops, markets and retail stores. Access to herbal products is easy; there are herbal markets on every street corner in the cities, towns and in communities. However, these markets are not regulated and often the products are not manufactured and stored according to proper standards. Most are packaged in plastic bottles without proper labels. 

Contrary to the belief that herbal medicines are safe, the truth is some of them are highly toxic and can interact with prescribed medicines when taken concurrently. People often co-administer herbal products and prescribed medicines without any knowledge of how the herbal product and the medicine will interact. 

The crucial factor is that herbal medicines often do not contain just a single ingredient — they have other ingredients with unknown adverse effects. 

The effects of mixing herbal and prescribed medicines can range from mild allergic reactions and abdominal upset to cerebral haemorrhage, liver damage and even death. 

When taken concurrently with them, herbal products can negatively affect the antagonistic pharmacological effects and absorption, distribution, metabolism and excretion of prescribed medicine. 

For instance, clinical data has shown that the popular herbal antidepressant Hypericum perforatum (St John’s wort) interacts with numerous drugs such as immunosuppressants, contraceptives and cardiovascular, antiretroviral and cancer drugs, to mention a few. 

Red, or Korean, ginseng (Panax ginseng) causes insomnia, tremors and headaches when co-administered with phenelzine, which is used to treat depression. Ginkgo (Ginkgo biloba) can induce seizures when combined with phenytoin or valproic acid and excessive bleeding when combined with blood-thinner warfarin. 

Consumers of herbal products are at risk due to the lack of knowledge about herb-drug interaction and education and awareness need to start in consultation rooms. Healthcare providers need to enquire about the use of herbal medicine because patients use them without medical supervision. Patients need reliable information about herb-drug interaction so they can make informed decisions about their health. 

Research has shown that there is minimal enquiry about herbal medicine use in consultation rooms. This is because, within the South African clinical context, the standardised form for patient record-keeping does not specifically reference the use of herbal medicine. 

The Department of Health and other stakeholders need to make sure herb-drug interaction is communicated in every consultation room for healthcare providers to be able to warn patients of any ill effects. 

Communication about herb-drug interaction would also assist in the reporting of adverse reactions to the South African Health Product Regulatory Authority’s adverse drug reaction monitoring system. The lack of communication about herb-drug interaction leads to poor documentation and, ultimately, undermines the effectiveness of the system.   

There is a dearth of reliable data on herb-drug interaction in South Africa due to poor documentation and reporting. Effective communication and educational intervention in consultation rooms could prevent patients from suffering adverse reactions to mixing conventional medicine and herbal remedies. 

Dr Tebogo Tsele-Tebakang is the head of the Department of Complementary Medicineat the University of Johannesburg’s Faculty of Health Sciences.