This document discusses food-drug interactions, defining them as when a nutrient affects how a medicine works or a drug affects nutrient metabolism. It describes types of interactions and how drugs can impact nutrient intake, absorption, production, metabolism, and excretion. Specific examples are given of drugs that can decrease vitamin absorption or increase nutrient loss. The document also discusses how foods can impact drug absorption and metabolism. Those most at risk of interactions are described as well as recommendations like monitoring high risk patients.

1. Food-Drug interactions
PROF . LOUAY LABBAN
FADA, CCN, CNC, CDE, RD

2. At the end of this lecture
 Definition of interaction
 Types of interactions
 Drug - Food (nutrient) interaction
 Food (nutrient) - Drug interaction
 Who’s at risk of interactions
 Recommendations

3. Function of a Drug
 A drug is taken to prevent or treat
sickness and disease.
 It is important to know the interactions in
order to better understand what happens
in the body when a drug is taken.

4.  The action of a drug taken orally generally
occurs in four steps:
(1) The drug dissolves in the stomach
(2) The drug is absorbed into the blood and
moves via the blood to the area of the
body that needs it

5. (3) The body reacts to the medicine
(4) The body gets rid of the drug by
way of the kidney, liver, or both

6. Definition of interaction
 Interaction happens when nutrient affects
the active material in a medicine so the
medicine cannot work the way it should.
 Or when drug affects nutrient metabolism

7. Types of interactions
1- Drug Nutrient ( effect on
nutritional status)
2- Food Drug ( effect on
efficiency of medication)

8. Ways of interactions
1- Medications can cause the following :
 Decrease Appetite
 Nausea
 Vomiting
 An unpleasant taste or dry mouth.
Food intake

9. 2- Medications can cause
Nutrient Absorption

10. 3- Medications can cause
Loss of a Nutrients

11. Drug-Nutrient Interaction
 Medications, both prescription or OTC, can
affect how the body uses nutrients.
 For individual taking medication for a long
time, drug-nutrient interactions may lead
to vitamin or mineral deficiencies.

12.  Appetite suppressants ( Amphetamines)
are medications that directly affect food
intake by depressing appetite
Food Intake

13.  Several cancer( Chemo Therapy )
medications (Carboplatin) may cause :
 Nausea
 Vomiting
 Sore and dry mouth
food intake

14. Medications can decrease
nutrient absorption
 Laxatives can decrease the absorption of
many vitamins and minerals .
 Laxatives cause food to move rapidly
through the body causing poor
nutrient absorption.

16.  Aluminum hydroxide contains in some
antacids can bind to phosphorus in food.
 This can prevent phosphorus to from
being absorbed and used by the bones
causing muscle weakness and severe
cases can cause osteomalacia and severe
pain on walking.

17.  Some cholesterol lowering medications
( statins ) reduce cholesterol by removing
bile acids.
 Fat-soluble vitamins A, D, E and K

18. Medications can slow down
nutrient production
 Vitamin K is produced by bacteria in the
intestines.
 Antibiotics kill harmful bacteria, but they
can also kill helpful bacteria which is
reponsible for vitamin K production.

19. Medications can interfere with
the body ability to metabolize
nutrients
 Birth control bills can lower level of
vitamin B6 and folate in the body.

20. Medications can increase a loss
of a nutrient
 Diuretics ( Lasix or Furosomide ) remove
excess water from the body. Some
diuretics may also increase loss of
potassium along with fluids.
 Potassium is very important in proper
functioning of heart and other muscles.

21.  Aspirin can cause increased loss of folate.
 Aspirin can cause ulcers, bleeding
Loss of Iron Anemia

22.  Anticonvulsant medications ( Clobazam) can
cause the liver to increase the removal of
vitamin D from the body . Vitamin D is
important for calcium absorption.

23. Food – Drug Interaction
 Food and nutrients can also alter a
medication’s effectiveness in many ways

24.  Nutrients could make the medications
work faster, slower, or even prevent
them from working at all.

25.  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.
 Sometimes a medication should be taken
with food.

26.  Food can increase or decrease the
absorption of a drug.
 Absorbing ─ than the intended dose may
decrease the effect of the drug.
 Absorbing + than the intended dose
increases the chance for an overdose
effect.

27.  Dietary calcium can bind to the antibiotic
tetracycline. As a result the body does not
absorb the amount of antibiotic intended.

28.  Foods or nutrients may interfere with a
drug’s metabolism or drug’s action in the
body.

29.  Aged and fermented foods

30.  Contain a chemical called tyramine that
interacts with a medication, Monoamine
Oxidase Inhibitor (Zoloft) leading to
High Blood Pressure.

31. Green vegetables
 Anticoagulants
 Foods high in vitamin K (such as broccoli,
lettuce, spinach, cucumberand kale)

32.  Vitamin K can decrease the effectiveness
of certain anticoagulant medications.

33.  Such foods may reduce the effectiveness
of anticoagulants (such as warfarin Some
Trade Names COUMADIN), increasing the
risk of clotting.
 Intake of such foods should be limited,
and the amount consumed daily should
remain constant

34. Oatmeal
 The fiber in oatmeal and other cereals,
when consumed in large amounts, can
interfere with the absorption of Digoxin
(CHF)
Some Trade Names
LANOXIN

35.  The type of beverage consumed with a
medication can also effect a medication’s
absorption.

36.  Usually, medications should be taken with
water .

37.  Acidic drinks, juices, and foods may
produce excess stomach acidity which
may
 Destroy the medication
 Cause the medication to dissolve in the
stomach instead of the intestine

38. Grapefruit juice
 Inhibits enzymes involved in drug
metabolism and thereby intensifies the
effect of certain drugs

39. Grapefruit juice
 Certain benzodiazepines (such as
triazolam) Valium and Xanax
 Calcium channel blockers (such as
felodipine, nifedipine, and nisoldipine)
 Cyclosporine
 Estrogen and oral contraceptives
 Certain statins (such as atorvastatin,
lovastatin, and simvastatin)

40. Who’s at risk?
 Some people may be at greater risk of
drug-nutrient interactions that others.
Those can include the following:

41.  People with poor diet or malnourished
 Growing infants and children
 Pregnant women
 Elderly
 People with serious health problems
 Patients taking 2 or more medications at
the same time.

42.  Patients using prescription and OTC
medications together.
 Patients taking medications for a long
period of time.
 Patients who drink alcohol and smoke
 Patients not following directions

43. The Elderly and Nutrient-Drug
Interactions
 Elderly persons are at a significant risk for
nutrient-drug interactions.
 This population often takes the highest
amount of medications, and with the use
of multiple drugs, certain problems may
exist.

44. Side effects of medications on
elderly
 Loss of appetite
 Reduced sense of taste and smell
 Swallowing problems
 Reduced nutrients absorption
 Low weight
 More…………

45. Malnutrition
 A common problem among elderly. Their
nutritional status may be already impacted
by decreased nutrient intake. This may
only worsen the effect of a possible
nutrient-drug interaction.
 Nutritional deficiencies may occur

46.  Nutritional status may also be impacted by
a drug's effect on the three main
nutrients:
 Carbohydrates
 Fat
 Protein

47.  The impact of the nutrient-drug
interaction may vary according to:
 Medicine taken
 The dose of the medicine given
 Number of medications taken
 The form taken (e.g., pill, liquid).

48. Recommendations
 Most drugs have nutritional status side
effects.
 Identify and monitor high risk patients,
those on multiple medications and
marginal diets
 Systems should be established so that
pharmacists can communicate with
nutrientionists regarding high risk patients

49. Thank you