Food Service & Nutrition - Summer 2018 - 20

MANAGEMENT NOTEBOOK

Five Everyday
Food-Drug
Interactions
that Matter
By Lisa Wu, R.Ph., BScPhm, and
Dorothy Tscheng, R.Ph., BScPhm, CGP

JIMMY VONG/SHUTTERSTOCK.COM

Potentially dangerous food-drug interactions should be on every nutrition manager's radar.

E

veryday foods can interact with
certain medications. These interactions may lead to reduced medication effectiveness or serious adverse drug
reactions. It is important to be mindful
of common food-drug interactions that
can impact patients in institutional health
care settings.
The relevance of food-drug interactions
continues to grow with the widespread use
of medications in an aging population.
Canadian data from 2016 indicated that
older adults were prescribed medications
from an average of seven different drug
classes, and those living in long-term care
facilities were prescribed more medications
compared to community dwellers.1
Other populations are also at high risk
for experiencing food-drug interactions.
These include persons with impaired liver
or kidney function, those living with poor
nutritional status resulting from chronic
diseases or experiencing recent weight loss,
individuals on multiple medications and
those at the extremes of age.2
Consideration needs to be given to the
increased risk of food-drug interactions
among these at-risk populations, especially
in health care institutions where food
menus are pre-set. Below are five everyday food-drug interactions that matter,

20

along with guidance for preventing serious
adverse events.

interacting medications in order to prevent
these serious adverse events.

FOODS CONTAINING CALCIUM
Calcium in dairy or fortified foods can
bind with some antibiotics, such as ciprofloxacin and tetracycline, and prevent
their absorption.3 The interaction can lead
to failure of the antibiotic to treat the
patient's infection. Examples of food products rich in calcium include milk, cheese,
yogurt and calcium-fortified juices.4,5
As a general rule, dairy or calciumfortified foods should be avoided
within two to four hours of taking an
interacting antibiotic.

GREEN LEAFY VEGETABLES
AND VITAMIN K
Green leafy vegetables are rich in vitamin
K, a nutrient that helps blood clot. Warfarin
is an anticoagulant medication that slows
blood clotting by interfering with vitamin
K activity.2 Eating large quantities of foods
rich in vitamin K or making sudden dietary
changes may reduce warfarin's effectiveness, leading to clots or comprising safety
resulting in bleeding.3 Examples of foods
high in vitamin K include kale, broccoli,
Brussels sprouts, parsley, spinach, cabbage
and collard greens.2,3
A balanced meal may include vitamin
K from green leafy vegetables as long as
there is consistency in the day-to-day diet.

GRAPEFRUIT AND GRAPEFRUIT JUICE
Grapefruit and its juice are known to
increase blood levels of numerous medications, including some cholesterol-lowering
medications known as statins (e.g., atorvastatin) and some high-blood-pressure
medications called calcium channel blockers (e.g., amlodipine).2-4 This interaction
can lead to increased adverse events such
as muscle pain (with some statins) and
severe low blood pressure (with some calcium channel blockers).4
It may be best to avoid consuming grapefruit and/or its juice for individuals taking

SALT SUBSTITUTES AND
POTASSIUM-RICH FOODS
Salt substitutes generally replace sodium
with potassium. Use of salt substitutes with
medications (e.g., angiotensin converting
enzyme [ACE] inhibitors like ramipril) that
increase the body's potassium, can lead to
hyperkalemia (high potassium levels in the
blood).6 Hyperkalemia can lead to irregular
heartbeats and heart palpitations.2
Continued on page 26

CA N A D I A N S O C I E T Y O F N U T R I T I O N M A N AG E M E N T N E W S - S U M M E R 2 0 1 8



Table of Contents for the Digital Edition of Food Service & Nutrition - Summer 2018

President’s Message
The ABCs of Medical Cannabis
Press Pause…Press On: Sustaining Energy and Wellness in the Workplace and Beyond
Holding the Planet on Your Plate: Ideas for Promoting Sustainable Menus
Ask an Expert
Management Notebook
CSNM Corporate Member Profile
Industry News & CSNM News
Continuing Education Quizzes
Food Service & Nutrition - Summer 2018 - Intro
Food Service & Nutrition - Summer 2018 - cover1
Food Service & Nutrition - Summer 2018 - cover2
Food Service & Nutrition - Summer 2018 - 3
Food Service & Nutrition - Summer 2018 - President’s Message
Food Service & Nutrition - Summer 2018 - 5
Food Service & Nutrition - Summer 2018 - The ABCs of Medical Cannabis
Food Service & Nutrition - Summer 2018 - 7
Food Service & Nutrition - Summer 2018 - 8
Food Service & Nutrition - Summer 2018 - 9
Food Service & Nutrition - Summer 2018 - Press Pause…Press On: Sustaining Energy and Wellness in the Workplace and Beyond
Food Service & Nutrition - Summer 2018 - 11
Food Service & Nutrition - Summer 2018 - 12
Food Service & Nutrition - Summer 2018 - 13
Food Service & Nutrition - Summer 2018 - Holding the Planet on Your Plate: Ideas for Promoting Sustainable Menus
Food Service & Nutrition - Summer 2018 - 15
Food Service & Nutrition - Summer 2018 - 16
Food Service & Nutrition - Summer 2018 - 17
Food Service & Nutrition - Summer 2018 - Ask an Expert
Food Service & Nutrition - Summer 2018 - 19
Food Service & Nutrition - Summer 2018 - Management Notebook
Food Service & Nutrition - Summer 2018 - CSNM Corporate Member Profile
Food Service & Nutrition - Summer 2018 - Industry News & CSNM News
Food Service & Nutrition - Summer 2018 - 23
Food Service & Nutrition - Summer 2018 - 24
Food Service & Nutrition - Summer 2018 - Continuing Education Quizzes
Food Service & Nutrition - Summer 2018 - 26
Food Service & Nutrition - Summer 2018 - cover3
Food Service & Nutrition - Summer 2018 - cover4
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