Avoiding Medication Side Effects

Older Bodies Handle Drugs Differently

As the body ages, its ability to break down substances can decrease. Because older people may not be able to metabolize drugs as well as they once did, they might need smaller doses of medicine per pound of body weight than young or middle-aged adults do.

Also, older adults frequently take more than one medication at a time. Medicines can interact with each other in unexpected ways, so anyone taking several medications at the same time should be extra careful.

Risks and Benefits

All medicines have risks as well as benefits. The benefits of medicines are that they can improve your health and well-being by doing what they were designed for, like treating a disease, curing infection, or relieving pain. The risks are the chances that something unwanted or unexpected will happen when you use medicines. Unwanted or unexpected symptoms or feelings that occur when you take medicine are called side effects.

Prescription and Over-the-Counter Medicine


There are two major types of medicines: prescription drugs and over-the-counter ones. The medications a doctor prescribes for you are called prescription drugs. You can only pick them up at a pharmacy.

Medicines you can get without a doctor's prescription, which you can buy at a grocery or convenience store, are called over-the-counter drugs.

It is important to remember that over-the-counter products include many different substances such as vitamins and minerals, herbal and dietary supplements, laxatives, cold medicines and antacids.

Any combination of prescription drugs and over-the-counter substances can interact with each other to cause unexpected or unwanted effects. Because of this, it is important to keep a list of all prescription drugs and over-the-counter remedies you take. The section below titled “Managing Your Medicines” explains how to create such a list.

Side effects can be relatively minor, such as a headache or a dry mouth. They can also be life-threatening, such as severe bleeding or irreversible damage to the liver or kidneys.

Tips to Avoid Side Effects

Stomach upset, including diarrhea or constipation, is a side effect common to many medications. Often, this side effect can be lessened by taking the drug with meals. Always check with your doctor, nurse, or pharmacist to see if you should take a particular medication with food.

Here are some more tips to help you avoid side effects.

  • Always inform your doctor or pharmacist about all medicines you are already taking, including herbal products and over-the-counter medications. Be sure to include products like pain relievers, antacids, alcohol, herbal remedies, food supplements, vitamins, hormones and other substances you might not think are medicines.
  • Tell your doctor, nurse, or pharmacist about past problems you have had with medicines, such as rashes, indigestion, dizziness, or loss of appetite .
  • Ask whether the drug may interact with any foods or other over-the-counter drugs or supplements you are taking.
  • Read the prescription label on the container or the drug information sheet that comes with your medication carefully and follow its directions. Make sure you understand how often, when and how much medicine to take each day.
  • If you experience side effects, write them down so you can report them to your doctor accurately.
  • Call your doctor right away if you have any problems with your medicines or if you are worried that the medicine might be doing more harm than good. He or she may be able to change your medicine to another one that will work just as well.
  • Don't mix alcohol and medicine unless your doctor or pharmacist says it's okay. Some medicines may not work well or may make you sick if taken with alcohol.

Active and Inactive Ingredients

Prescription and over-the-counter medicines almost always contain several ingredients. Some of the ingredients in a medicine are not directly involved in its main job. These are called inactive ingredients. Examples of inactive ingredients include the substances that give a lozenge color or flavor, or ingredients that ensure the drug within a capsule gets released at a controlled rate.

The active ingredients in medicines are the chemical compounds that work with your body to treat your condition or bring relief of your symptoms. Learn which active ingredients are in the prescription and over-the-counter medicines you are taking.

For example, over-the-counter pain relievers usually contain one or more of the active ingredients below:

  • acetaminophen
  • ibuprofen
  • naproxen sodium
  • aspirin

Some medicines are designed to treat more than one condition, so they have more than one active ingredient. Many cold and flu remedies are an example of this. They might contain a combination of ingredients to sooth a sore throat, calm a cough, stop up a runny nose and bring down a fever.

Check Your Intake of Active Ingredients

Don't take more than one medicine that contains the same active ingredient(s). For example, if your cough syrup contains acetaminophen, don’t take a pain reliever that contains acetaminophen while you are using the cough syrup. Taking more than one medicine that has the same active ingredient could result in getting too much of that ingredient. Too much of any one ingredient might damage your liver or lead to other serious health problems.

Check Medication Labels

Check the labels of your prescription medicines before you start taking them to ensure you are not allergic to any of the ingredients. Make sure your doctor and pharmacist have an up-to-date list of your allergies so they don’t give you a medicine that contains something you are allergic to.

Always read the labels on the over-the-counter products you are taking to find out whether the active ingredients have side effects. For example, antihistamines can cause drowsiness. Caffeine, which is present in some over-the-counter medicines, can interact with certain drugs or can cause problems with underlying conditions such as high blood pressure.

For more informaiton, download the “Medicine and You: A Guide for Older Adults” brochure from the Food and Drug Administration [PDF].

Information from NIHSenior Health.