We thought there was something significant about this, and we needed to check with the bottler, Johnston said. We found the bottler in Tullahoma, from Tullahoma we were referred to the corporate headquarters in Dallas, and from there we were referred to a customer service division in St. Louis. We sent a formal letter to a customer service representative, who in turn delivered the letter to someone in their formulation division.

We didn ™t expect them to give us their formula. That ™s a trade secret. But we were very interested in whether the beverage had a bergamottin component. After several days, and another phone call, the company responded by email saying that Sun Drop contains the type of ingredient you refer to in your letter.

Johnston says the admission was enough to convince him and Milstone of the cause of Turner ™s high cyclosporine levels.

Both say a formal study is needed to examine the extent of the effects of Sun Drop, and a growing number of other drinks containing citrus products, on the disruption of excretion and absorption of cyclosporine and certain other prescription drugs.

Although there isn ™t a body of published evidence yet, there is strong evidence to suggest beverages containing bergamottin also alter the absorption and excretion of statins (HMG-CoA reductase inhibitors), or as they are more commonly known, cholesterol-lowering drugs, affecting a high percentage of the U.S. population on this class of drugs.

Johnston and Milstone have submitted an article for publication in the journal Transplantation regarding the effect of Sun Drop on cyclosporine levels, suggesting that such citrus-containing products be labeled to include this information.

Turner, who has recovered completely from the ordeal and is doing well, is a bit humble about his discovery, its potential benefit to transplant patients, and to all those taking cholesterol-lowering drugs.

I guess it ™s good for transplant patients to know about Sun Drop, he said. I would hope this might make food and beverage manufacturers think about the way products are labeled, and hopefully provide better labeling with appropriate cautions for people.