DNA Direct: Your Genes in Context

Login

Register as a New User

forgot your password?
view privacy policy

Problems accessing your account?
Email support@dnadirect.com or call us at 1-877-646-0222.

Testing for Drug Response

Related Genetic Tests

CYP450 Genes

Includes a personalized report, a letter for your doctor, and toll-free support

Price: $250.00 - $630.00

Order Testing

Pre-test & Post-test Consultation

Our genetic experts can counsel you before and after testing.

Price: $250 per hour

Call to schedule: 1-877-646-0222

Related Genetic Tools

Drug Response Test Finder

Over half of all medications are affected by 3 genes that you can test for: CYP 2D6, 2C9 and 2C19. This tool to see which drugs are affected by these genes.

Start the Tool

THE CYP450 GENES

Lifestyle Issues and Drug Metabolism

Many lifestyle factors, such as diet, use of herbal supplements, smoking and alcohol use can affect your ability to metabolize a particular drug. The degree to which these factors affect drug metabolism, however, is quite varied.

Lifestyle factors can affect drug metabolism in different ways. They can interfere with the drug, preventing it from being absorbed or broken down by the body. They can increase the effects of the drug, as if a higher dose of the drug had been taken. They can cause side effects. Or, they can reduce the effectiveness of a drug.

There are many different enzymes involved in drug metabolism.

Some, such as 3A4, appear to be especially sensitive to components in food, while other enzymes, such as 2D6, are not sensitive to environmental influences. The clinically significant differences in 2D6 metabolism tend to be related to the gene itself – this is why 2D6 testing can be used to predict a person's drug metabolism for certain classes of drugs.

How lifestyle factors affect drug metabolism and the specific drugs they affect is still under research. That's why genetic tests are not yet available for all drugs or all enzymes at this time.

Diet, Herbs, and Other Influences

The tables below lists some examples of food, herbal supplements and other lifestyle issues that are known to affect drug responses.

Foods & Drug Metabolism
Herbs, Supplements & Drug Metabolism
Smoking, Alcohol, Caffiene & Drug Metabolism

Most of these interactions are mild and are not medically significant for the average person. However, for certain people who have specific gene types, such as Poor Metabolizers, some of these interactions can become significant. So if you know your genotype, are on one or more of these medications, or are concerned about drug interactions, talk with your doctor or pharmacist.

Foods & Drug Metabolism

Foods	Affected Drug Metabolism System	Affected Drugs
Fruit juices
Grapefruit juice	CYP3A4, CYP1A2	Cyclosporin (Restasis, Cicloral), terfenadine (Seldane), midazolam (Versed, Hypnovel and Dormicum), erythromycin (Robimycin, E-Mycin), many HIV protease inhibitors, calcium channel antagonists, statins, clozapine (Clozaril), fluvoxamine (Luvox), imipramine (Tofranil) and theophylline (Theo-Dur, Respbid)
Seville Orange juice	CYP3A4	Cyclosporin (Restasis, Cicloral), terfenadine (Seldane), midazolam (Versed, Hypnovel and Dormicum), erythromycin (Robimycin, E-Mycin), many HIV protease inhibitors, calcium channel antagonists and statins
Grape juice	CYP1A2	clozapine (Clozaril), fluvoxamine (Luvox), imipramine (Tofranil) and theophylline (Theo-Dur, Respbid)
Vegetables
Cruciferous vegetables (brussel sprouts, cabbage, broccoli and cauliflower)	CYP1A2, UGTs and GSTs	clozapine (Clozaril), fluvoxamine (Luvox), imipramine (Tofranil) and theophylline (Theo-Dur, Respbid)
Watercress	CYP2E1, UGTs and GSTs	Chlorzoxazone (Paraflex, Parafon Forte), halothane, enflurane, oxazepam (Serax), lorazepam (Ativan), zidovudine (Retrovir), morphine
Cooked Meats
char-grilled, fryed or smoked meats such as beef, chicken or fish	CYP1A2	clozapine (Clozaril), fluvoxamine (Luvox), imipramine (Tofranil) and theophylline (Theo-Dur, Respbid)
Overall food intake
Chronic low calorie intake	decrease drug metabolism	All drugs, including phenazone, theophylline (Theo-Dur, Respbid)
Chronic low intake of protein	decrease drug metabolism	All drugs, including phenazone, theophylline (Theo-Dur, Respbid)

Herbs, Supplements & Drug Metabolism

Herbs & Supplements	Affected Drug Metabolism System	Affected Drugs
St John's Wort	CYP3A4	Cyclosporin (Restasis, Cicloral), terfenadine (Seldane), midazolam (Versed, Hypnovel and Dormicum), erythromycin (Robimycin, E-Mycin), many HIV protease inhibitors, calcium channel antagonists and statins
Garlic	CYP3A4	cyclosporin (Restasis, Cicloral), indinavir (Crixivan)
Ginseng	CYP2E1	Chlorzoxazone (Paraflex, Parafon Forte), halothane and enflurane
Licorice	CYP3A, CYP1A2, CYP2B1	cyclosporin (Restasis, Cicloral), indinavir (Crixivan)

Smoking, Alcohol, Caffiene & Drug Metabolism

Smoking,Alcohol & Caffeine	Affected Drug Metabolism System	Affected Drugs
Smoking	CYP1A2	Clozapine (Clozaril), olanzapine (Zyprexa, Zydis)
Red wine	CYP3A4, CYP2E1	Cyclosporin (Restasis, Cicloral), terfenadine (Seldane), midazolam (Versed, Hypnovel and Dormicum), erythromycin (Robimycin, E-Mycin), many HIV protease inhibitors, calcium channel antagonists, statins and Chlorzoxazone (Paraflex, Parafon Forte),
Caffeine-containing beverages	CYP1A2	clozapine (Clozaril), fluvoxamine (Luvox), imipramine (Tofranil) and theophylline (Theo-Dur, Respbid)