Announcer: Today's medicines are treating and curing more illnesses than ever before and there is a wide variety of prescription and over-the-counter medicines available to help you if needed.

Fleur Sack, M.D.: Prescription medications have made the lives of patients so much better. We can treat and avoid so many different diseases that it's quite incredible in this day and age.

Announcer: But people do not always react to medicines in the same way. James Payne found that the pain reliever he was taking was just not right for him.

James Payne: When the arthritis in my hands began to interfere with my work on the keyboard on the computer, I went to the doctor and he prescribed ibuprofen. I first noticed an irregular heartbeat and it scared the hell out of me.

Announcer: Mr. Payne reported the problem to his pharmacist.

Don Bottoni: I said, "Palpitations -- how long has this been going on?" And he started talking about it and I said, "Let me go and look at your profile," so I went to the computer and I saw that he was taking ibuprofen, 600 milligram tablets, four times a day.

James Payne: He said, "Mr. Payne, you're taking ibuprofen, aren't you?" And I said, "Yes."

Don Bottoni: And I told him, "Why don't we try this? Why don't you go back and talk to your doctor about discontinuing the ibuprofen for a few days."

Announcer: The doctor agreed the ibuprofen should be discontinued. Within a day, the palpitations had stopped and Mr. Payne felt like a new man. In the future it may be possible to avoid problems like this one and have doctors prescribe the right medicine in the right amount for each person. Finding ways to personalize your medicines is the focus of a new type of research called pharmacogenetics.

Rochelle Long: Pharmacogenetics is the science of looking at how our inheriteds, or our genes, our heredity, influences our responses to drugs. When different people take medications, they respond differently. One of the reasons they respond differently is encoded in our genes.

Announcer: Everyone's genes are different and this is one of the reasons people process medicines differently.

Rochelle Long: Drugs act differently in people for a variety of reasons, some of which have to do with lifestyle, like diet or exercise, for example, but others have to do with differences in our genes. Genes, which encode proteins, are different among individuals. We will absorb and transport drugs differently, we will respond to their therapeutic effects differently. We'll also eliminate drugs at different rates.

Announcer: Other factors that could affect the way your body handles medicines are age and the number of medications you may be taking.

Rochelle Long: Drugs often act differently in older people than in younger people. There are a number of reasons for that but one of them is that many body processes slow down. Another reason is that older people often take multiple drugs at the same time so they can interact and that can be a problem if you're not prepared for it.

Announcer: Medicines are important for all age groups, including children and younger adults. But it is older adults that consume more medicines than any other group. Taking multiple medicines can sometimes lead to drug interactions.

Rochelle Long: Older people do take multiple medications, especially today, more than ever and it's significant to know that because drug interactions can result. If people take medicines that are cleared or eliminated by the same proteins in the body, one medicine could compete for the same protein that another medicine is also competing for. The net effect could be higher levels in the blood of both drugs and that could even be dangerous.

Announcer: Scientists working in pharmacogenetic research hope to come up with tests that doctors can use to prescribe medicines that are tailored to the individual patient.

Rochelle Long: The real promise of pharmacogenetics is knowing and being able to use research information that tells us that one size does not fit all when it comes to drugs. Different drugs will be appropriate for different people in different amounts. The science of pharmacogenetics will lead to information that will help doctors predict this upfront with simple tests in their offices.