Genetic Pharmacology

For Patients and Families

Some genes affect the way medicines work in the body. When comparing a group of people, there can be slight differences in each gene’s structure. These differences can affect how people react to medicine.

1. Some gene differences might make it harder for the body to get rid of some medicines. This means that the usual doses of such medicines could give some people unexpected side effects.
2. Some gene differences can cause the body to use up a medicine too fast. This means that normal doses won’t work as  well and the person may need higher doses. 
3. Some gene differences won’t let certain medicines work in the body at all.  This means that a different medicine may work better. 

• The test may improve the chances that the medicine will help you as intended.
• The test may lower the chance of severe side effects from the medicine.
• The PG test for the medicine may only need to be done once in a lifetime. The test looks at common gene differences. If the common gene differences are found in your blood, then the test will not need to be repeated.
• The gene tested today may be important for medicines that you need in the future.

• The test looks only at common gene differences. This means if the test does not find any of the common gene differences, you could still have one or more rare gene differences. The test will not detect rare gene differences. Some of these rare differences might affect how you react to the medicine.
• Gene differences are one of many factors that can affect how you react to medicine. A few examples of other factors are your age, weight, other medicines and illnesses.  Your doctor will need to consider these factors along with the PG test results.

In the future, some of these common gene differences may be found to be associated with other medical conditions.

The test results may be important for other family members. Biologic brothers, sisters and parents may have one or more of the same tested genes in common.