Make sure your doctor knows about any allergies and adverse reactions you have had to medicines. This can help you avoid getting a medicine that can harm you.
When your doctor writes you a prescription, ask that the purpose for the medication be included and make sure you can read it. If you can’t read your doctor’s handwriting, your pharmacist might not be able to either.

Ask for information about your medicines in terms you can understand—both when your medicines are prescribed and when you receive them.
What is the medicine for? How am I supposed to take it, and for how long? What side effects are likely? What do I do if they occur? Is this safe to take with other medicines or supplements I am taking? What food, drink, or activities should I avoid while taking this medicine? What are the brand and generic names of the medications? When is the best time to take it? What should I do if I miss a dose? Does this replace anything else I was taking? Where and how do I store it?

When you pick up your medicine from the pharmacy, ask:
Is this the medicine that my doctor prescribed? A study by the Massachusetts College of Pharmacy and Allied Health Sciences found that 88 percent of medicine errors involved the wrong drug or the wrong dose.

If you have any questions about the directions on your medicine labels, ask.
Medicine labels can be hard to understand. For example, ask if "four doses daily" means taking a dose every 6 hours around the clock or just during regular waking hours.

Ask your pharmacist for the best device to measure your liquid medicine. Also, ask questions if you’re not sure how to use it.
Research shows that many people do not understand the right way to measure liquid medicines. For example, many use household teaspoons, which often do not hold a true teaspoon of liquid. Special devices, like marked syringes, help people to measure the right dose. Being told how to use the devices helps even more.

Ask for written information about the side effects your medicine could cause.
If you know what might happen, you will be better prepared if it does happen or if something unexpected happens instead. That way, you can report the problem right away and get help before it gets worse. A study found that written information about medicines can help patients recognize problem side effects and then give that information to their doctor, pharmacist or other health care professional.