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Home > 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.
There are many things you can do to prevent and prepare for side effects. Before you take any medicine, talk to your doctor or pharmacist about:
In general, you can ask your doctor if you can take less of the medicine or try another one.
Here are some tips to help you manage some common side effects from medicines.
What to know or do
Loss of appetite
Upset stomach (nausea)
Feeling nervous or on edge
Sensitive to the sun
Taking certain 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.
Interactions 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 mistaken for 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 take.
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 form 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 of medicines.
Include herbal and dietary supplements, vitamins, and 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 blood thinners or nonsteroidal anti-inflammatory drugs (NSAIDS), such as ibuprofen.
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 theinstructionssay. 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 information, see 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 doctor.
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.
Even 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:
February 11, 2021
Author: Healthwise StaffMedical Review: E. Gregory Thompson MD - Internal MedicineAdam Husney MD - Family MedicineTheresa O'Young PharmD - Clinical Pharmacy
Current as of: February 11, 2021
Author: Healthwise Staff
Medical Review:E. Gregory Thompson MD - Internal Medicine & Adam Husney MD - Family Medicine & Theresa O'Young PharmD - Clinical Pharmacy
To learn more about Healthwise, visit Healthwise.org.
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