Abstract
Simultaneous oral intake of herbs, supplements, foods and drugs with other drug(s) may result in pharmacokinetic or pharmacodynamic interactions with the latter. Although these interactions are often associated with unwanted effects such as adverse events or inefficacy, they can also produce effects that are potentially beneficial to the patient. Beneficial pharmacokinetic interactions include the improvement of the bioavailability of a drug (i.e., by enhancing absorption and/or inhibiting metabolism) or prolongation of a drug’s plasma level within its therapeutic window (i.e., by decreasing excretion), whereas beneficial pharmacodynamic interactions include additive or synergistic effects. Mechanisms by which pharmacokinetic interactions can cause beneficial effects include enhancement of membrane permeation (e.g., structural changes in the epithelial cell membranes or opening of tight junctions), modulation of carrier proteins (e.g., inhibition of efflux transporters and stimulation of uptake transporters) and inhibition of metabolic enzymes. In the current review, selected pharmacokinetic interactions between drugs and various compounds from different sources including food, herb, dietary supplements and selected drugs are discussed. These interactions may be exploited in the future to the benefit of the patient, for example, by delivering drugs that are poorly bioavailable in therapeutic levels via alternative routes of administration than parenteral injection.
Highlights
Many patients are taking food, herbs, supplements and/or over-the-counter health products together with their prescribed medications [1,2]
Since certain drugs are mainly excreted via the kidneys, the organic anion transporters (OATs) play a role in the reduction of plasma levels of such drugs via excretion
Fleisher et al [32] found that tangeretin and nobiletin significantly inhibited P-gp-mediated by increasing intracellular concentration of a small molecule tyrosine kinase inhibitor (TKI), dasatinib, by 314% and 476%, respectively when compared to the control of dasatinib alone [32]
Summary
Many patients are taking food, herbs, supplements and/or over-the-counter health products together with their prescribed medications [1,2]. Pharmacodynamic interactions mainly involve diverse reactions at receptor sites resulting in antagonistic or synergistic effects as well as causing changes in physiological environments, while pharmacokinetic interactions affect the absorption, distribution, metabolism and excretion of the co-administered agent (e.g., food component, herb, supplement, health product ingredient) and/or co-administered drug [1,2,4,5] These interactions have been associated with negative effects, which include either adverse effects/toxicity or insufficient plasma concentrations of the co-administered drug(s). Figure indirectly alsowill [P-gp], cytochrome P450 [CYP450] and organic anion transporters [OAT] 1 and 3) [1,4,6] This illustrates different possible areas that may be targeted for beneficial pharmacokinetic interactions result in cost savings and improved patient compliance [1]. The mechanisms of these interactions as well as examples of such interactions are discussed in more in the sections below
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
