1. Guidelines to Lower Risk of Drug-Nutrient Interactions
Presented by
Janice Hermann, PhD, RD/LD
OCES Adult and Older Adult Nutrition Specialist

2. Types of Interactions Drug-Nutrient Interactions
Effect of a medication on food or a nutrient in food
Both prescription and over-the-counter medications can affect the way your body uses nutrients in food
Nutrient-Drug Interactions
Effect of food or a nutrient in food on a medication
Types on Interactions
A Drug-Nutrient Interaction is the effect of a medication on food or a nutrient in food.
A Nutrient-Drug Interaction is the effect of food or a nutrient in food on a medication.
How Drugs and Nutrients Interact
Both prescription and over-the-counter medications can affect the way your body uses nutrients in food. In addition, certain foods or nutrients in food can affect the action of medication.
A drug-nutrient interaction refers to the effect of a medication on food or a nutrient in food. Medications interact with foods and nutrients in several ways. Medications can decrease appetite or change the way a nutrient is absorbed, metabolized, or excreted.
A nutrient-drug interaction refers to the effect of food or a nutrient in food on a medication. Dietary nutrients can affect medications by altering their absorption or metabolism. The food you eat could make the medications you take work faster, slower, or even prevent them from working at all.

3. Nutrition Implications
Little chance taking a medication for a short time will affect your nutritional status
However, using some medications for months or years may affect your nutritional health
Changing diet to include more foods rich in vitamins and minerals is preferred to taking vitamin or mineral supplements
Nutrition Implications
Such interactions raise concerns that medications may lead to nutritional deficiencies or that your diet may change how a medication works.
There is little chance that taking a medication for a short time, such as a ten day treatment, will affect your nutritional status. However, use of some medications for months or years may affect your nutritional health.
This does not mean that if you are taking a medication you need to use a vitamin and or mineral supplement. Changing diet to include more foods rich in vitamins and minerals is preferred to taking vitamin or mineral supplements. In fact, vitamin and or mineral supplements taken in excess can affect how a medication works.

4. Drug-Nutrient Interactions
Medications, can affect nutrients by:
Decreasing food intake
Decreasing nutrient absorption
Slowing down nutrient production
Interfering with nutrient metabolism
Increasing nutrient excretion
Drug-Nutrient Interactions
Medications, both prescription and over-the-counter, can affect how the body uses nutrients. For individuals taking medications for long periods of time drug-nutrient interactions may lead to vitamin or mineral deficiencies. Medications, can affect nutrients by:
Decreasing food intake
Decreasing nutrient absorption
Slowing down nutrient production
Interfering with nutrient metabolism
Increasing nutrient excretion

5. Drug-Nutrient Interactions: Food Intake
Some medications can affect nutritional health by causing poor food intake due to:
Decreased appetite
Nausea or vomiting
Unpleasant taste or dry mouth
Gastrointestinal sores or inflammation
Decrease food intake:
Some medications can affect nutritional health when they cause decreased appetite; interfere with taste or smell; cause nausea or vomiting; cause unpleasant taste or dry mouth; cause sores or inflammation which results in pain or discomfort when eating. This can affect nutritional health by causing poor food intake. These types of complications are only significant to nutritional health when they continue for a long time.

6. Drug-Nutrient Interactions: Food Intake
Many medications may cause loss of appetite or nausea in some people, but it usually subsides after the first few doses
However, nutritional health can be affected if decreased food intake persists
Decrease food intake:
Many medications may cause nausea in some people, but usually nausea subsides after the first few doses. However, weight loss and malnutrition may occur if nausea persists.

7. Drug-Nutrient Interactions: Food Intake
Examples:
Appetite suppressants are medications which affect food intake by depressing appetite
Several cancer medications and treatments may dramatically reduce food intake by causing:
Loss of appetite
Changes in taste perception
Nausea, vomiting
Dry mouth
Mouth and intestinal sores or inflammation
Decreased food intake:
Example: Appetite suppressants are medications which directly affect food intake by depressing appetite.
Example: Amphetamines can change taste perception.
Example: Some antidepressants may cause dry mouth.
Example: Several cancer medications and treatments may cause loss of appetite, changes taste perception, nausea, vomiting, dry mouth or sores dramatically reducing food intake.

8. Drug-Nutrient Interactions: Nutrient Absorption
Some medications can affect nutritional health by decreasing nutrient absorption due to:
Decreasing time in intestine
Altering stomach acidity
Damaging intestinal lining
Competing for absorption
Binding nutrients
Decrease nutrient absorption:
Some medications can affect nutritional health by decreasing the absorption of nutrients. Medications can decrease nutrient absorption by decreasing the time nutrients are in the intestine, changing the acidity of the digestive tract, damaging the lining of the intestine, competing for absorption or binding to nutrients.

9. Drug-Nutrient Interactions: Nutrient Absorption
Examples:
Laxatives can cause food to move rapidly through the intestinal track which can decrease nutrient absorption
Antacids can lower stomach acidity which can may interfere with iron, folate and vitamin B12 absorption
Many cancer medications and treatments can damage the intestinal lining which can decrease nutrient absorption
Decrease nutrient absorption:
Example: Laxatives can decrease the absorption of many vitamins and minerals. Laxatives cause food to move rapidly through the body causing poor nutrient absorption.
Example: Antacids lower stomach acidity and may interfere with iron, folate and vitamin B12 absorption
Example: Several cancer medications and treatments damage the lining of the intestine decreasing nutrient absorption.

10. Drug-Nutrient Interactions: Nutrient Absorption (cont.)
Examples:
Some anticonvulsants can compete for absorption with folate resulting in decreased folate absorption
Some cholesterol lowering medications reduce cholesterol by removing bile acids
Bile acids are needed to absorb essential fatty acids and fat-soluble vitamins
As a result some cholesterol lowering medications can reduce absorption of fat-soluble nutrients
Decrease nutrient absorption (cont.):
Example: Some anticonvulsants can decrease folate absorption.
Example: Some cholesterol lowering medications reduce cholesterol by removing bile acids. Bile acids are needed to absorb the fat-soluble vitamins A, D, E, and K. As a result some cholesterol lowering medications can reduce absorption of fat-soluble vitamins.

11. Drug-Nutrient Interactions: Nutrient Production
Some medications can affect nutritional health by slowing down nutrient production
Decrease nutrient production:
Some medications can affect nutritional health by slowing down the production of nutrients.

12. Drug-Nutrient Interactions: Nutrient Production
Vitamin K produced by bacteria in the intestine
Antibiotics kill harmful bacteria, but they can also kill helpful bacteria
Killing helpful vitamin K producing bacteria can result in decreased vitamin K production
Decrease nutrient production:
Example: Vitamin K is produced by bacteria in the intestines. Antibiotics kill harmful bacteria, but they can also kill helpful bacteria. Killing the helpful vitamin K producing bacteria decreases the amount of vitamin K produced in the intestine.

13. Drug-Nutrient Interactions: Nutrient Metabolism
Some medications can affect nutritional health by interfering with body’s ability to metabolize nutrients due to:
Affecting enzyme systems
Competing with enzyme systems
Interfere with nutrient metabolism:
Some medications can affect nutritional health by interfering with the body’s ability to metabolize nutrients. Some medications use similar enzyme systems or compete for carriers in the body.

14. Drug-Nutrient Interactions: Nutrient Metabolism
Examples:
Some anticonvulsants alter liver enzyme activity causing increased metabolism of folate, vitamin D, and vitamin K
Methotrexate resembles folate in structure and competes with enzymes that converts folate to its active form, this can result in folate deficiency
Interfere with nutrient metabolism:
Example: Methotrexate resembles folate in structure and competes with the enzyme that converts folate to its active form. Use of methotrexate can cause folate deficiency.
Example: Some anticonvulsants alter the activity of liver enzymes causing increased metabolism of folate, vitamin D, and vitamin K.

15. Drug-Nutrient Interactions: Nutrient Excretion
Some medications can affect nutritional health by increasing nutrient excretion due to:
Decreased kidney reabsorption
Increased urinary excretion
Increase nutrient excretion:
Some medications can affect nutritional health by increasing nutrient excretion. Some medications can affect mineral reabsorption by the kidneys or increase nutrient losses by increasing urinary excretion.

16. Drug-Nutrient Interactions: Nutrient Excretion
Diuretics remove excess fluid from the body
Some diuretics may also increase loss of potassium along with fluids
Potassium is very important in proper functioning of the heart and other muscles
Large amounts of aspirin can cause increased loss of folate
Increase nutrient excretion:
Example: Diuretics remove excess fluid from the body. Some diuretics may also increase loss of potassium along with fluids. Potassium is very important in proper functioning of the heart and other muscles.
Example: Large amounts of aspirin can cause increased loss of folate. Also, large amounts of aspirin over long periods of time may cause stomach bleeding that could result in iron deficiency. Over time iron deficiency can lead to anemia.

17. Drug-Nutrient Interactions: Nutrient Excretion
Examples:
Some anticonvulsant medications can cause the liver to increase removal of vitamin D from the body
Isoniazid, an antituberculosis medication, is similar in structure to vitamin B6 and induces vitamin B6 excretion
Since treatment is for 6 months, B6 supplements are routinely given to prevent deficiency
Increase nutrient excretion:
Example: Some anticonvulsant medications can cause the liver to increase the removal of vitamin D from the body. Vitamin D is needed for calcium absorption.
Example: Isoniazid, an antituberculosis medication, is similar in structure to vitamin B6 and induces excretion of vitamin B6. Since this medication must be taken for at least six months B6 supplements are routinely given to prevent deficiency.

18. Food-Drug Interactions
Some foods or nutrients in food can also alter a medication’s effectiveness by:
Decreasing medication absorption
Interfering with medication metabolism
Interfering with medication removal
Food-Drug Interactions
Food and nutrients can also alter a medication's effectiveness in many ways such as:
Decreasing medication absorption
Interfering with medication metabolism
Interfering with medication removal

19. Nutrient Interactions: Medication Absorption
Some foods or nutrients in food can increase or decrease medication absorption by:
Decreasing stomach emptying
Binding to medications
Competing for absorption
Altering acidity
Decreasing medication absorption:
Food or nutrients in food can increase or decrease the absorption of a drug by:
Decreasing stomach emptying rate
Binding to medications
Competing for absorption
Altering acidity

20. Nutrient Interactions: Medication Absorption
Absorbing less than the intended dose lowers the chance a medication will work properly
Absorbing more than the intended dose increases the chance of an overdose effect
Decreasing medication absorption:
Absorbing less than the intended dose may decrease the effect of the drug. Absorbing more then the intended dose increases the chance for an overdose effect.

21. Nutrient Interactions: Medication Absorption
Medications are typically absorbed more quickly when the stomach is empty
Having food in the stomach typically will slow down a medications absorption
Decreasing medication absorption:
Example: Drugs are absorbed more quickly into the body when the stomach is empty. Having food in the stomach will slow down a medication's absorption.

22. Nutrient Interactions: Medication Absorption
Some medication should be taken with food
Some medication should be taken on an empty stomach (1 hour before or 2 hours after eating)
Read the directions to see if a medication should or should not be taken with food
Decreasing medication absorption:
Sometimes a medication should be taken with food. Other medications should be taken on an empty stomach, one hour before or two hours after eating. It is important to read the directions to see if a medication should or should not be taken with or without food.

23. Nutrient Interactions: Medication Absorption
Examples:
Dietary calcium can bind to the antibiotic tetracycline making it unavailable for absorption
Amino acids compete for absorption with levodopa
Decreasing medication absorption:
Example: Dietary calcium can bind to the antibiotic tetracycline. As a result the body does not absorb the amount of antibiotic intended.
Example: Dietary amino acids compete for absorption with levodopa.

24. Nutrient Interactions: Medication Absorption
Examples:
Acidity of food or beverage consumed with a medication can affect absorption
Some medications are better absorbed in an acidic environment
Other medications can be damaged by an acid environment, these types of medications are often available in coated forms to resist stomach acidity
Decreasing medication absorption:
Example: The type of food or beverage consumed with a medication can affect a medication's absorption. Some medications are better absorbed in an acidic environment. Other medications can be damaged by an acid environment, these types of medications are often available in coated forms to resist the stomach acidity.

25. Food-Drug Interactions: Medication Metabolism
Some foods or nutrients in foods may interfere with a medication’s metabolism or action in the body by:
Affecting enzyme systems
Interacting with medications
Having a similar chemical structure resulting in competition
Interfering with medication metabolism:
Foods or nutrients may interfere with a drug's metabolism or a drug's action in the body by interfering with enzymes that metabolize medications or acting as a medication antagonist.

26. Food-Drug Interactions: Medication Metabolism
Examples:
Components in grapefruit juice
Inactivate enzymes that metabolize many medications which can result in increased medication levels
Aged and fermented foods
Contain a chemical called tyramine that interacts with a medication, monoamine oxidase inhibitor, which can result in dangerously high blood pressure
Vitamin K
Structurally similar to the anticoagulant warfarin which can decrease the effectiveness of warfarin
Interfering with medication metabolism
Example: Components in grapefruit juice and whole grapefruit inactivate enzymes that metabolize many medications. The lack of enzyme action increase medication levels which can lead to overdose effects.
Example: Aged and fermented foods contain a chemical called tyramine that interacts with a medication, monoamine oxidase inhibitor. This interaction can result in dangerously high blood pressure.
Example: Vitamin K is structurally similar to the anticoagulant warfarin. Vitamin K can decrease the effectiveness of warfarin.

27. Food-Drug Interactions: Medication Removal
Some food or nutrients in foods may interfere with removal of a medication from the body by:
Affecting enzymes involved in preparing medications for removal
Altering urine pH
Interfering with medication removal:
Foods or nutrients may interfere with the removal of a medication from the body by affecting liver enzymes involved in preparing medications for removal from the body or altering the acidity of the urine.

28. Food-Drug Interactions: Medication Removal
Examples
Liver enzymes prepare medications for removal from the body
These enzymes require nutrients to work properly
If nutrients are not present the medication may stay active in the body longer than intended
Quinidine is excreted more readily in an acidic urine
Foods that cause the urine to be more basic, such as sodium bicarbonate, may reduce quinidine excretion
Interfering with medication removal:
Example: Liver enzymes prepare medications for removal from the body. These enzymes require nutrients to work properly. If the nutrients are not present the medication may stay active in the body longer than it is supposed to. This may cause an overdose effect.
Example: Quinidine is excreted more readily in an acidic urine. Foods that cause the urine to be more basic, such as sodium bicarbonate, may reduce quinidine excretion.

29. Many Medications
These are just a few examples to understand how medications and nutrients can interact, this is not indented to be a complete list of possible interactions
There are thousands of medications on the market and numerous new medications that come out ever year
Many Medications
These are just a few examples to understand how medications and nutrients can interact, this is not indented to be a complete list of possible interactions.
There are thousands of medications on the market and numerous new medications that come out ever year.

30. Alcohol Interacts With Medications
Alcohol and medications do not mix
Alcohol can adversely affect medications
Alcohol can slow down or speed up how the body metabolizes a medication
Medication action can be either intensified or reduced
In some cases, mixing alcohol and medications can be fatal
Alcohol
Alcohol and medications do not mix well. Alcohol can adversely affect medications. Alcohol can slow down or speed up how the body metabolizes a medication. As a result, medication action can be either intensified or reduced. In some cases, mixing alcohol and medications can be fatal.

31. Alcohol Interacts With Medications
A rule of thumb is to avoid alcoholic beverages when taking prescription and over-the-counter medications
Alcohol
A rule of thumb is to avoid alcoholic beverages when taking prescription or over-the-counter medications.

32. Nutrient Supplements
Nutrient supplements themselves can result in drug-nutrient interactions
In excessive amounts, vitamin and mineral supplements can act like drugs instead of nutrients
Nutrients in excessive amounts may:
Compete with other nutrients for absorption, transport or metabolism
Have a direct overdose effect
Nutrient Supplements
Nutrient supplements themselves can result in drug-nutrient interactions. In excessive amounts vitamins and minerals act like drugs instead of nutrients. Nutrients in excessive amounts may compete with other nutrients for absorption, transport or metabolism. In excess, nutrients can have a direct overdose effect.   
Example: Large amounts of zinc can interfere with copper and iron absorption. Similarly, large amounts of iron can interfere with zinc absorption.

33. Follow Directions
It is very important to follow the directions on how to take a medication
Many people do not take prescription or over- the-counter medications properly
Following directions on how to take a medication can affect how or if a medication will work properly
The Importance of Following Directions
It is important to follow the directions on how to take a medication. Many people do not take prescription or over-the-counter medications properly. Following the directions on how to take a medication can affect how or if a medication will work properly.

34. Who Is At Greater Risk Persons who are poorly nourished
Persons with serious health problems
Growing children
Pregnant women
Older adults
Who Is At Risk Of Drug-Nutrient Interactions?
Some people may be at greater risk of drug-nutrient interactions than others. Those considered at higher risk for drug-nutrient interactions include:
Persons who are poorly nourished.
Persons who have serious health problems.
Growing children.
Pregnant women.
Older adults.

35. Who Is At Greater Risk (cont.)
Persons taking two or more medications at the same time
Persons using prescription and over-the- counter medications together
Persons not following medication directions
Persons taking medications for long periods of time
Persons who drink alcohol excessively
Who Is At Risk Of Drug-Nutrient Interactions (cont.)?
Persons taking two or more medications at the same time.
Persons using prescription and over-the counter medications together.
Persons not following medication directions.
Persons taking medications for a long period of time.
Persons who drink alcohol excessively.

36. Lower The Risk of Drug-Nutrient Interactions
Eat a healthy diet
Follow directions on how to take medications
Both prescription and over-the-counter
Read warning labels
Do not share medications
How to Lower The Risk Of Drug-Nutrient Interactions
Eat a healthy diet using the USDA Daily Food Plan.
Follow directions on how to take medication (prescription and over-the-counter).
Read warning labels on both prescription and over-the-counter medications.
Do not share medications with others or take other peoples medications.

37. Lower The Risk of Drug-Nutrient Interactions (cont.)
Tell your physician all the medications you are taking both prescription and over-the-counter
Tell your physician and pharmacist about any new symptoms that develop when taking a medication
Keep a list of all medications
Ask if you have any questions
How to Lower The Risk Of Drug-Nutrient Interactions (cont.)
Tell your physician about any other medications you are taking, including over-the-counter medications and alcohol.
Tell your physician and pharmacist about any new or intensified symptoms that develop when taking a medication.
Keep a list of all medications (prescription and over-the-counter) that you use.
If you have questions, ask your pharmacist or physician for answers.

38. Questions To Ask Your Physician
What is the medication for?
Medication name
Medication purpose
How should I take the medication?
How often, how long
How to store
Recommendations on consuming food and/or beverages with medication
What should I expect?
Expected outcomes
Precautions
Side-effects
Questions To Ask Your Physician When You Get A Prescription
What is the medication for? (medication name, medication purpose).
How should I take the medication? (dosing schedule, how long, storage recommendations, recommendations on consuming food and/or beverages with the medication).
What should I expect? (expected outcomes, precautions, side-effects).