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Home > Wellness > Health Library > Dealing With Medicine Side Effects and Interactions
Medicines are a big part of treatment for many health problems.
They fight harmful bacteria, relieve pain, and save lives. Medicines have
helped cure diseases that used to have no cure.
But there is a
downside to medicines.
Medicines work in a delicate balance with
your body and with each other. Sometimes the balance tips, and this can cause
side effects or medicine interactions.
Health Tools help you make wise health decisions or take action to improve your health.
All medicines have side effects. But
many people don't feel the side effects, or they are able to deal with them.
Here are some important things to think about:
Anyone can feel side
effects from a medicine, but there is no way to know for sure if a medicine
will cause side effects for you. It may depend on how much of the medicine you
take, how old you are, how much you weigh, whether you are male or female, and
what other health problems you may have. Older adults are more likely to have
side effects than younger adults.
You may notice side effects when
you start to take a medicine, change the dose, or stop using the medicine. A
medicine you've often taken without getting side effects may suddenly cause
side effects. Or side effects may stop.
many things you can do to prevent and prepare for side effects. Before you take
any medicine, talk to your doctor or
you can ask your doctor if you can take less of the medicine or try another
Here are some tips to help you manage some common side
effects from medicines.
What to know or do
medicines together may cause a bad reaction. This is called an interaction. For
example, one medicine may cause side effects that create problems with other
medicines. Or one medicine may make another medicine stronger or weaker.
A medicine you take for one health problem also can make another
health problem worse. For example, a medicine you use for a cold could make
high blood pressure worse.
can happen among any of these:
If you have several doctors, and if some of them don't know
all of the medicines you're taking, a bad reaction can be mistaken as an
illness. For example, some medicines can cause memory problems that are
dementia. Falls can be a sign of too much medicine,
rather than frailty.
But just because you take several medicines
doesn't mean you'll have problems. To be safe, make sure that all your doctors
know you're taking medicines prescribed by another doctor and about
over-the-counter medicines, herbs, supplements, and illegal drugs you
It is hard to know whether you're having a side effect or interaction. If
you've talked with your doctor about it, you may be able to recognize the
symptoms of an interaction. How likely you are to have an interaction depends
on how many medicines you're taking, how much of a medicine you take, how old
you are, how much you weigh, whether you are male or female, and what other
health problems you may have.
If you think that you are having an
interaction, talk to your doctor or
pharmacist. He or she will review the medicines you
are taking to see if there is a problem. Your
doctor or pharmacist can make suggestions to help an interaction while still
making sure that you're getting the treatment you need.
Here are some things you can
do to be sure that you're taking medicines safely.
Make a list of all the medicines you take, and update it every
time you get a new medicine. Use
this formthis form(What is a PDF document?) to track your medicines. If you stop taking a medicine, take it off your
list. Keep a copy in your purse or wallet, and take it with you each time you
see your doctor or see a new doctor. Have each doctor keep in your file a copy of your list
Include herbal and dietary
over-the-counter medicines on your list, because they
can cause problems when you take them with some medicines. For example, ginkgo
biloba, ginseng, and large amounts of garlic may make bleeding more likely.
That means they could be dangerous when taken with other medicines that may
cause bleeding, like the blood thinner warfarin (such as Coumadin) or
nonsteroidal anti-inflammatory drugs (NSAIDS), such as
Talk with your pharmacist or doctor before you take a new prescription, over-the-counter medicine, or
supplement. It may be helpful to schedule a visit or call your
pharmacist ahead of time to let him or her know that
you want to talk about the medicines you take. Talk about:
Take your medicines as your doctor or the instructions say. This will make sure you get the most benefit, and it
will help you avoid interactions and side effects. Be sure you know how much to
take, when to take it, and whether you can take the medicine with food, drink,
or alcohol. Also be sure you know what to do if you miss a dose. This applies
to prescription or over-the-counter medicines, supplements, and herbs. For more
Taking Medicines as Prescribed.
Use a drug interaction checker. Ask your doctor or pharmacist
to run your medicine list through a drug interaction checker. This checks for
medicines that can have bad interactions. If you find a problem, talk to your
Use one drugstore or pharmacy, if possible. The pharmacist will know which medicines you take and will
watch for interactions. If you fill prescriptions at more than one pharmacy,
make sure that each of them has the same information about your medicines.
Know which medicines to avoid. Because of
possible bad reactions, some people may need to avoid some medicines. For
example, if you have
heart failure and are taking digoxin, you may have
problems with clarithromycin—an antibiotic used for pneumonia—because it
increases the effect of digoxin. Your doctor and pharmacist will check for drug interactions and help you know what medicines are safe to take.
something that seems as harmless as grapefruit juice can change how your body
uses medicines. Cholesterol-lowering medicines (statins) and high blood
pressure medicines are two examples of medicines that grapefruit juice affects.
If you take these medicines, your doctor may suggest that you don't drink
grapefruit juice. For more information, see the topic
Grapefruit Juice and Medicines.
Other Works Consulted
Lorig K, et al. (2006). Managing your medicines. In Living a Healthy Life with Chronic Conditions, 3rd ed., pp. 239–253. Boulder, CO: Bull.
Pronsky ZM, Crowe JP (2012). Clinical: Food-drug interactions. In LK Mahan et al., eds., Krause's Food and the Nutrition Care Process, 13th ed., pp. 209–228. St Louis: Saunders.
Current as of:
January 24, 2014
E. Gregory Thompson, MD - Internal Medicine & Theresa O'Young, PharmD - Clinical Pharmacy
How this information was developed to help you make better health decisions.
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