Food-Drug interactions

PROF . LOUAY LABBAN

FADA, CCN, CNC, CDE, RD

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

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.

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

(3) The body reacts to the medicine

(4) The body gets rid of the drug by way of the kidney, liver, or both

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

Types of interactions

1- Drug Nutrient ( effect on nutritional status)

2- Food Drug ( effect on efficiency of medication)

Ways of interactions

1- Medications can cause the following :

Decrease Appetite

Nausea

Vomiting

An unpleasant taste or dry mouth.

Food intake

2- Medications can cause

Nutrient Absorption

3- Medications can cause

Loss of a Nutrients

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.

Appetite suppressants ( Amphetamines) are medications that directly affect food intake by depressing appetite

Food Intake

Several cancer( Chemo Therapy ) medications (Carboplatin) may cause :

Nausea

Vomiting

Sore and dry mouth

food intake

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.

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.

Some cholesterol lowering medications ( statins ) reduce cholesterol by removing bile acids.

Fat-soluble vitamins A, D, E and K

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.

Medications can interfere with the body ability to metabolize

nutrients

Birth control bills can lower level of vitamin B6 and folate in the body.

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.

Aspirin can cause increased loss of folate.

Aspirin can cause ulcers, bleeding

Loss of Iron Anemia

Anticonvulsant medications ( Clobazam) can cause the liver to increase the removal of

vitamin D from the body . Vitamin D is important for calcium absorption.

Food – Drug Interaction

Food and nutrients can also alter a medication’s effectiveness in many ways

Nutrients could make the medications

work faster, slower, or even prevent them from working at all.

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.

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.

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

Foods or nutrients may interfere with a drug’s metabolism or drug’s action in the

body.

Aged and fermented foods

Contain a chemical called tyramine that interacts with a medication, Monoamine Oxidase Inhibitor (Zoloft) leading to

High Blood Pressure.

Green vegetables

Anticoagulants

Foods high in vitamin K (such as broccoli, lettuce, spinach, cucumberand kale)

Vitamin K can decrease the effectiveness of certain anticoagulant medications.

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

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

The type of beverage consumed with a medication can also effect a medication’s

absorption.

Usually, medications should be taken with water .

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

Grapefruit juice

Inhibits enzymes involved in drug metabolism and thereby intensifies the effect of certain drugs

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)

Who’s at risk?

Some people may be at greater risk of drug-nutrient interactions that others. Those can include the following:

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.

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

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.

Side effects of medications on elderly

Loss of appetite Reduced sense of taste and smell Swallowing problems Reduced nutrients absorption Low weight More…………

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

Nutritional status may also be impacted by a drug's effect on the three main nutrients:

Carbohydrates Fat Protein

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).

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

Thank you