Food-Drug Interactions

Food-Drug Interactions

Definition of Terms
* Drug-nutrient interaction: the result of the action between a drug and a nutrient that would not happen with the nutrient or the drug alone
* Food-drug interaction: a broad term that includes drug-nutrient interactions and the effect of a medication on nutritional status

Food-Drug Interaction
* For example, a drug that causes chronic nausea or mouth pain may result in poor intake and weight loss
Key Terms
* Bioavailability: degree to which a drug or other substance reaches the circulation and becomes available to the target organ or tissue
* Half-life: amount of time it takes for the blood concentration of a drug to decrease by one half of its steady state level
* Side effect: adverse effect/reaction or any undesirable effect of a drug

Other Terms
* Bioavailability: % free to function
* Absorption rate: % absorbed and time for absorption
* Transported: amount in blood (free or bound)
* Metabolized: altered by enzymes in tissues
* Mixed-function oxidase system (MFOS): enzyme system that metabolizes drugs, carcinogens, compounds in foods, etc.

Pharmacokinetics
Movement of drugs through the body by
* Absorption
* Distribution
* Metabolism
* Excretion
Pharmacodynamics
Benefits of Minimizing Food Drug Interactions
* Medications achieve their intended effects
* Improved compliance with medications
* Less need for additional medication or higher dosages
* Fewer caloric or nutrient supplements are required
* Adverse side effects are avoided
* Optimal nutritional status is preserved
* Accidents and injuries are avoided
* Disease complications are minimized
* The cost of health care services is reduced
* There is less professional liability
* Licensing agency requirements are met

Therapeutic Importance
Patients at Risk for Food-Nutrient Interactions
* Patient with chronic disease
* Elderly
* Fetus
* Infant
* Pregnant woman
* Malnourished patient
* Allergies or intolerances

Food and Drug-Related Risk Factors
* Special diets
* Nutritional supplements
* Tube feeding
* Herbal or phytonutrient products
* Alcohol intake
* Polypharmacy
* Drugs of abuse
* Non-nutrients in foods
* Excipients in drugs or food

Malnutrition Effect on Drugs
Food/Nutrient Effects on Drugs
Absorption
Food/Nutrient Effects on Drugs
Metabolism
Changes in diet may alter drug action
Grapefruit Inhibits Metabolism of Many Drugs
Drugs known to interact with grapefruit juice
* Anti-hypertensives (filodipine, nifedipine, nimodipine, nicardipine, isradipine)
* Immunosuppressants (cyclosporine, tacrolimus)
* Antihistamines (astemizole)
* Protease inhibitors (saquinavir)
* Lipid-Lowering Drugs (atorvastatin, lovastatin, simvastatin)
* Anti-anxiety, anti-depressants (buspirone, diazepam, midazolam, triazolam, zaleplon, carbamazepine, clomipramine, trazodone

Food/Nutrient Effects on Drug Action: MAOIs
Food/Nutrient Effects on Drug Action: Caffeine
Food/Nutrient Effects on Drug Action: Warfarin
Food/Nutrient Effects on Drug Action: Alcohol
Drug Effects on Nutrition: Metabolism
Drug Effects on Nutrition: Excretion
Drug Effects on Nutrition: Absorption
Drug Side Effects that Affect Nutritional Status
Examples of Drug Categories That May Decrease Appetite
Drugs That May Increase Appetite
Drugs Affecting Oral Cavity, Taste and Smell
Drugs that Affect the GI Tract
Examples of Drug Classes That Cause Diarrhea
Drugs That May Lower
Glucose Levels
Drugs That Raise Blood Glucose
Nutrition Implications of Excipients in Drugs
Nutrition Implications of Excipients in Drugs
Food/Nutrient Effects on Drugs – Enteral Feedings
Enteral Nutrition and Drugs
MNT for Food-Drug Interactions
TJC 2006 Standards Re Education on Medications
Avoiding Food-Drug Interactions: Prospective
Avoiding Food-Drug Interactions: Retrospective
Avoiding Food-Drug Interactions: Example
Summary

Food-Drug Interactions.ppt