David Bailey, PhD (Emeritus)
David Bailey completed undergraduate studies in Pharmacy (1968) and graduate work in Pharmacology (M.Sc. 1970; Ph.D. 1973) at the University of Toronto. After post-doctoral training in Pharmacology at the University of Saskatchewan and work in clinical drug development for the pharmaceutical industry, he returned to academia in 1986. Thereafter, his research focused on mechanistic and translational clinical pharmacological investigations related to drug interactions.
The novel 1991 publication of grapefruit - drug interactions is notable (Lancet 1991; 337: 268-269). The finding that grapefruit caused inhibition of drug metabolism in humans likely represented the first example of a food producing such an effect. The translational aspect is illustrated by product information for a number of highly prescribed or essential medications now warning of risk of adverse events by such interactions. A label stating, "Do NOT take with Grapefruit Juice" is often affixed to appropriate prescription vials. There is concern for a noticeable boost in oral drug bioavailability following inactivation of a crucial intestinal drug-metabolizing enzyme (cytochrome P450 3A4; CYP3A4) to cause overdose toxicity.
Currently his research has focused on the effect of foods, herbal products and their constituents on drug transporters. Grapefruit and other fruit juices (orange, apple) and contained flavonoids (naringin) were recently shown to inhibit an intestinal active drug uptake transporter (organic anion transporting polypeptide 1A2; OATP1A2) to diminish oral drug absorption discernibly in humans.
This likely represented a new type of food-drug interaction resulting in the clinical concern of potential loss of benefit of medications essential for the treatment of serious medical conditions.