IHR April 2014

Page 62

Drug interactions with cutting-edge ingredients We explore drug interactions with cutting-edge natural health product ingredients. By Thang Nguyen, B. ScH, CerRAP (Scientific Regulatory Associate of Dicentra)

There has been a surge of interest in ingredients derived from natural sources with benefits to human health. The ingredients particularly gripping the public eye are those with associations to heart health, blood sugar balance, weight management and antioxidant properties. These ingredients include green coffee bean, raspberry ketones, garcinia cambogia (Malabar tamarind), resveratrol and moringa. The demand for these ingredients is high, as consumers increasingly desire to treat and maintain their health using natural means. However, as they may also be taking pharmaceuticals, it is crucial that consumers are aware of the drug interactions possible with these ingredients.

Ingredient Green Coffee Bean

Green coffee bean extracts are recognized by Health Canada to help maintain healthy blood pressure levels, support cardiovascular health, provide antioxidants and complement a healthy lifestyle that incorporates a calorie-reduced diet and regular physical activity for individuals involved in a weight management program. As green coffee bean demonstrates hypotensive effects, combined use with anti-hypertensives such as beta-blockers has the potential to lower blood pressure to undesirable levels. The hypotensive effect of the green coffee bean’s primary constituent ferulic acid has been neutralized in animal studies when administered in combination with anti-cholinergic drugs like atropine. Care is warranted if green coffee bean is used in combination with iron supplements, as the chlorogenic acids in green coffee bean are potent inhibitors of iron absorption.

Raspberry Ketones

Though Health Canada does not recognize raspberry ketones for any official health benefit at this time, it has been licensed as a source of antioxidants. Though often advertised as a weight management ingredient, the fatburning effect, while supported in cells and animals, has not been demonstrated clinically in humans. Nonetheless, as raspberry ketones have demonstrated lipolytic effects in human cell lines and a favourable cholesterol profile when administered to animals, consumers should exercise caution in using raspberry ketones in combination with anti-lipemic and anti-obesity drugs where the additive effect could be deleterious to human health. There has been some clinical evidence that raspberry ketones decreases the international normalized ration (INR) of warfarin, a common anticoagulant, where its blood-clotting properties were weakened.



Health concerns

(who takes these drugs?)

Anti-Hypertensives (beta-blockers): Acebutolol, betaxolol, levobetaxolol, nadolol, propanolol

Patients with high blood pressure (hypertension) or heart disease taking anti-hypertensives

Anti-cholinergic Drugs: Atropine, benztropine, dicyclomine, diphenhydramine, scopolamine, tolterodine,

Patients taking beta-blocker medication for anxiety

Iron Supplements: Iron multivitamins, Prenatal multivitamins containing iron

Anti-lipemic drugs: Ezetimibe, cholestyramine, clofibrate Anti-obesity drugs: Orlistat, sibutramine, phendimetrazine Anti-coagulants: Warfarin, heparin, dicumarol

Patients taking anti-cholinergic medication for insomnia, dizziness, and respiratory disorders like asthma Patients taking iron supplements for iron deficiency and anemia

Patients with high levels of lipids in the bloodstream (hyperlipidemia) taking anti-lipemic drugs for weight control, loss or management Patients taking anti-obesity drugs Patients taking anticoagulants for cardiovascular disorders (heart attack, stroke, deep vein thrombosis) lipids in the bloodstream (hyperlipidemia) taking anti-lipemic drugs