Although they’re meant to keep us healthy, when errors are made in prescribing, dispensing and administering medications, the outcome can be serious, even deadly. In fact, according to a report by the Institute of Medicine (IOM), approximately 1.5 million preventable adverse drug events occur each year in the U.S.

Whether you’re on a prescription drug, use an over-the-counter medication, or take supplements, there are some simple ways to avoid medication mistakes.

1. Know what you take.
Keep an updated list of all of your medications— including dosage and frequency— and know what you take them for. Bring the list and the bottles with you to every doctor’s appointment. Even better, carry the list with you at all times or memorize the names in case you end up in the emergency room.

2. Ask questions.
When your doctor gives you a new prescription, ask for both the brand and generic names so you know you’re getting the right one from the pharmacy. Although most doctors send prescriptions electronically, it’s a good idea to have a hard copy as well.

Ask about drug or food interactions, if you should take the medication with food or on an empty stomach, and know exactly how long to take it since the pharmacy may include extra pills, Dr. Jennifer Trachtenberg, a pediatrician in New York City, said.

3. Talk to the pharmacist.
When you pick up your prescription, ask the pharmacist if the dosage is new, if anything else has changed, and if there are interactions you need to know about. Talking to the pharmacist is also a good idea if you were in the emergency room or urgent care because an oversight is more likely in those situations, Dr. Kristine Arthur, an internist at Orange Coast Memorial Medical Center in Fountain Valley, Calif., said.

4. Read everything.
Always read the label on the bottle and the informational insert to ensure you’re taking the right medication and you’re taking it as prescribed. Every bottle will have a description for the medication, such as “a white oval shaped pill with number 130.”

5. Use a pill box.
Instead of trying to remember if you took your pills, or run the risk of taking too many, a pill box can help you keep track.

“I find that for anyone who has to take pills more than once a day, using a pill box is really handy and it can be very efficient,” Arthur said.

6. Download an app.
Studies show that people are more likely to take their medicine correctly when they use an app that sends reminders.

7. Weigh yourself.
Knowing how much you, and particularly your children, weigh is important since most medication dosages are based on weight, not age.

8. Use the right measurement.
Although the amount of medicine in a teaspoon is 5 milliliters, using a kitchen teaspoon isn’t a good idea because the amount can vary anywhere between 3 and 9 milliliters. In fact, the American Academy of Pediatrics recently released a policy statement calling for all liquid medicines to be prescribed and administered in milliliters. To avoid an improper dose, use the dropper or container that came with the medication.

9. Throw out old bottles.
One of the most common mistakes people make is refilling an old bottle with a new prescription or combining the two. Not only will the old bottle have the incorrect information, but it can cause confusion. Plus, some people may take an old antibiotic, for example, without their doctor’s ok. This is problematic because it might not be the right antibiotic or you may not even need it. When you get a new prescription, only use the new bottle and check the FDA’s website on how to properly dispose of the old one.

10. Keep drugs out of reach.
According to a recent report by Safe Kids Worldwide, 64,000 children were treated in an emergency room for medicine poisoning in 2012. In 3 out of 4 cases, the medicine was a parent or grandparent’s.
Some bottles, especially for older adults, are made to be easy to open but are not childproof. So store all medication, even vitamins with iron, high enough or locked away where kids can’t reach them.

“Iron can be toxic for children in big doses,”  Trachtenberg said.

11. Be careful with over-the-counter medications.
Since some over-the-counter medications might contain the same ingredients as prescription medications, or other OTC’s, you could be double dosing without realizing it. Be sure to ask your doctor or pharmacist before taking anything new.

12. Ask about supplements.
Vitamins and supplements can interact with other drugs or the same herb could be in two different supplements. What’s more, even if they’re marketed as natural, supplements are not regulated by the FDA.

“Some dietary supplements are frankly dangerous,” said Dr. Patricia Salber, of Larkspur, Calif., founder and host of “The Doctor Weighs In.” “Anything that you put in your mouth is something your physician should know about.”

13. Don’t share meds.
When people start to feel better and stop taking their medications, they may share them with other family members or even their pets, Salber said. If your doctor says you no longer need the medication, get rid of it.

14. Don’t alter it.
Cutting, crushing or mixing pills with food can alter the medication, interfere with its efficacy or be dangerous.

15. Rethink allergic reactions.
According to a study presented at the American College of Allergy, Asthma and Immunology’s annual scientific meeting last year, 94 percent of people who thought they were allergic to penicillin were not.  There are tests to determine if you’re allergic but if you remember what your symptoms were, it may have just been a side effect not an allergy, Salber said.