Health Canada has received a published case report of a potential drug-herb interaction between Efavirenz ( Sustiva ) and a Ginkgo biloba product.
Efavirenz is a selective non-nucleoside reverse transcriptase inhibitor that is indicated for the treatment of HIV-1 infection in combination with other antiretroviral agents. It is known to interact with various medications, foods and natural health products.
The case involved a 41-year-old HIV-infected man on antiretroviral therapy consisting of Zidovudine, Lamivudine and Efavirenz, with good viral suppression ( less than 50 copies/mL ) for 10 years.
Routine blood work detected a rise in the patient’s HIV viral load ( to 1350 copies/mL ).
Upon questioning, he denied any missed doses but revealed the daily use of NHPs including omega-3 fatty acid, calcium, magnesium, vitamin D, a multivitamin, flax oil, rutin, and 300 mg of an unspecified Ginkgo biloba product per day for the previous 2 months.
Additionally, he used horse chestnut periodically for hemorrhoids treatment.
After discontinuation of the Ginkgo biloba product and horse chestnut, the patient’s HIV was re-suppressed by the same antiretroviral therapy one month later.
Based on a previous published case report, a similar drug-herb interaction between Ginkgo biloba and Efavirenz was suspected.
People living with HIV/AIDS often use a combination of prescription and non-prescription health products, including natural health products,
Health care professionals are encouraged to remind patients to disclose the use of all health products, including non-prescription drugs and natural health products.
Drug- natural health product interactions may lead to serious adverse reactions and/or a reduction in the drugs’ intended benefits. ( Xagena )
Source: Health Canada, 2014