DNA Direct's Gene Tests for Drug Response can be useful for people considering or taking many common medications. Testing positive as a "Poor Metabolizer" can affect how a person responds to these drugs, whether they experience adverse side effects, and their risk for drug-drug interactions.

Note, more than one gene can affect a medication and reasearch is ongoing, so these may not be complete lists.

CYP2D6: 25% of Medications
CYP2C9: 5-10% of Medications
CYP2C19: 15% of Medications
FDA Specially Labeled Drugs

The CYP2D6 Gene: 25% of Medications

The CYP2D6 gene affects 25% of drugs in clinical use. If genetic test results indicate that a person is a 2D6 Poor Metabolizer, these drugs may not be effective due to improper or slow processing of the drug by the patient; or when several drugs are administered at once, their risk for severe adverse reactions may increase due to the slower metabolism of one of the drug’s in their regimen.

In addition, some medications (including some antidepressants), can interfere with the metabolism of other 2D6-processed drugs and result in adverse side effects or lowered therapeutic benefit. The medications below are strongly affected by 2D6 gene variations, according to current research.

The CYP2C9 Gene: 5-10% of Medications

The CYP2C9 gene affects 5-10% of drugs in clinical use. If you are a 2C9 Poor Metabolizer, these drugs may not be effective due to limited metabolism; or when several drugs are administered at once, your risk for severe adverse reactions may increase due to your slower metabolism. In addition, some medications can interfere with the metabolism of 2C9 drugs and result in adverse side effects or lowered therapeutic benefit. The medications below are strongly affected by 2C9 gene variations, according to current research.

The CYP2C19 Gene: 15% of Medications

The CYP2C19 gene affects 15% of drugs in clinical use. If you are a 2C19 Poor Metabolizer, these drugs may not be effective due to limited metabolism; or when several drugs are administered at once, their risk for severe adverse reactions may increase due to their slower metabolism. In addition, some medications can interfere with or "inhibit" the metabolism of 2C19-processed drugs and result in adverse side effects or lowered therapeutic benefit.

FDA Specially Labeled Drugs

The FDA has begun including gene-and-drug-response information in drug labels, so that healthcare providers and patients have updated information on how genetics, along with other factors (age, gender, liver and kidney function, other medications) can influence a person’s response to a particular drug. Today about 10% of the drug labels approved by the FDA include such information, and that number is increasing with each meeting of the FDA’s advisory committees.