SS-129-R08
For more information, visit the Ohio Department of Aging web site at: http://www.goldenbuckeye.com
and Ohio State University Extension’s “Aging in Ohio” web site at: http://seniorseries.osu.edu
Adverse Drug-Drug and Food-Drug
Medication Interactions
Because older adults often take There are many physical signs that
more medications than younger can happen due to a side effect. These
adults, the number of side effects include:
increases with age. However, side ■ fatigue (being tired)
effects frequently go unnoticed or are
not always caught in older people for ■ constipation or diarrhea
the following reasons: ■ confusion
■ Drug reactions sometimes act like ■ incontinence (not being able to
signs or symptoms of disease (e.g., control your bladder or frequent
dementia). urination)
■ Symptoms of a drug reaction are ■ frequent falls
thought to be caused by an existing ■ depression (feeling sad or blue)
illness or the start of a new health
problem. ■ weakness or tremors
■ Physical reactions to medication, ■ excess drowsiness or dizziness
such as being tired, falling, or ■ agitation or anxiety
weight loss, may be mistakenly ■ decreased sexual behavior
labeled as “normal” aging.
The Ohio
The Ohio Department of Aging, The Aging Network, The Ohio State University,
The United States Department of Agriculture and County Commissioners Cooperating.
Department
of Aging
SS-129-R08—page 2
If a problem develops shortly ■ Mineral oil taken with fat-soluble
after a person begins taking a drug, vitamins (A, D, E, K) can decrease
alert a doctor right away. Sometimes the absorption of the vitamins.
it takes time for a side effect to occur, In addition to interacting
making it less likely the problem will with each other, over-the-counter
be associated with taking medications. medications can also interact with
prescription medication. Some
Drug-Drug Interactions examples of this type of interaction
Another type of reaction is a include:
drug-drug interaction. A drug-drug ■ Aspirin can significantly increase
interaction occurs when the effect of the effect of blood thinning
one drug is altered by the presence medications (anticoagulants), thus
of another drug in the body. For increasing the risk of excessive
example: bleeding.
■ One drug might reduce or increase ■ Antacids can interfere with drug
the effects of another drug. absorption of antibiotics (i.e.,
■ Two medications taken together tetracycline), thereby reducing the
may produce a new and dangerous effectiveness of the drug in fighting
interaction. infection.
■ Two medications that work the ■ Antihistamines, often used for
same way may produce an effect allergies and colds, can increase
that is greater than would be the sedative effects of barbiturates,
expected from taking just one drug tranquilizers, and some
if they are taken at the same time. prescription pain relievers.
In addition to prescription ■ Decongestants in cold and
medications, over-the-counter cough medications can interact
medications can interact with each with diuretics or “water” pills to
other. Some examples include: aggravate high blood pressure.
■ Taking a cough medication with ■ Iron supplements taken with
alcohol at the same time as an antibiotics can reduce or stop the
antihistamine medication can ability of the antibiotics to fight
increase drowsiness and decrease infection. The chemicals in the
alertness. supplement and the antibiotic
SS-129-R08—page 3
bind together in the stomach, ■ Stimulation or suppression of the
instead of being absorbed into the appetite.
bloodstream. ■ Medications may alter how
■ Salt substitutes can interact with nutrients are used in the body.
“water” pills or blood pressure ■ Herbs may interact with many
medication to increase blood medicines.
potassium levels. This can result
in symptoms of nausea, vomiting, If you are taking medication, the
muscle cramp diarrhea, muscle food you eat or the supplements you
weakness, and cardiac arrest. take could cause the medication to
work incorrectly.
These are just a few of the many
interactions that can occur when Check with your pharmacist on
multiple medications are taken how food can affect your specific
together. Check with your doctor medications.
or pharmacist to make sure your
medications do not have the potential Factors Affecting the Extent
to interact. of Interaction Between Foods
and Medications
Drug and Food Interactions The impact of food-drug
Sometimes when medications interactions will depend on a variety
are taken with food or meals, they of intervening factors. For example:
can have less of an effect than if they ■ The dosage of the drug.
were taken on an empty stomach.
Additionally, vitamin and herbal ■ A person’s age, size, and state of
supplements taken with prescribed health.
medication can result in side effects. ■ When the food is eaten and when
Some examples of how foods and the medication is taken.
medications can interact include: Avoidance of drug interactions
■ Food can speed up or slow down does not necessarily mean avoiding
the action of a drug. medications or foods. In the case of
Tetracycline and dairy products, these
■ Some medications may cause should simply be taken at different
vitamins and minerals to not work times, rather than eliminating one or
properly in the body. the other from the diet. Having good
SS-129-R08—page 4
information about the medications
you take and timing your medications
around your food intake can help to
avoid drug interaction problems.
Reference
Senior Series Volume 2, The Center
on Rural Elderly, University of
Missouri System.
Revised by Dr. Bella Mehta, PharmD (August 2007).
Visit Ohio State University Extension’s web site “Ohioline” at: http://ohioline.osu.edu
Ohio State University Extension embraces human diversity and is committed to ensuring that all
research and related educational programs are available to clientele on a nondiscriminatory basis
without regard to race, color, religion, sex, age, national origin, sexual orientation, gender identity or
expression, disability, or veteran status. This statement is in accordance with United States Civil Rights
Laws and the USDA.
Keith L. Smith, Ph.D., Associate Vice President for Agricultural Administration and Director, Ohio
State University Extension
TDD No. 800-589-8292 (Ohio only) or 614-292-1868
