National Pharmacy Week is Oct. 18 to 24, and pharmacists want you to know that they are always available to advise you about your medications. Remember to “Communicate to Stay Healthy—Talk With Your Pharmacist.” The more you know, the better you will feel.

What do those prescription instructions really mean? Have you ever been confused by the instructions on your prescription? If so, you may not be alone. The best way to avoid problems with medications is to make sure you understand clearly what your prescription instructions mean before you leave the pharmacy.

Ask the pharmacist to explain the directions for use. That way, you’ll be sure of exactly how to take your medicine. The directions will serve as a reminder of the more complete set of instructions your pharmacist gave you face-to-face.

The American Pharmaceutical Association, representing the nation’s pharmacists, has put together this list of common instructions and what they mean:

Take medication on an empty stomach. Food and some beverages in your stomach may interfere with the absorption of certain medications, or slow the time it takes them to begin working. To avoid these pitfalls, when indicated, take the medication either one hour before, or two hours after, eating or drinking. You should take all medication with a full glass of water.

Take one dose four times daily. During a 24-hour period, this medication should be taken four times, with about six hours between each dose. Spacing the four doses over the entire day will ensure a constant level of medication in your body. Most medications with this direction will work fine if taken four times during the time you are awake (for example, at breakfast, lunch, supper and bedtime). Ask your pharmacist which way is right for your medicine. Remember to make arrangements for your children to receive their medications at the proper times while at school or daycare.

Keep in refrigerator. Medications requiring storage in the refrigerator should generally be kept at a temperature between 36 and 46 degrees Fahrenheit to maintain their potency. Refrigerate only medications that have this instruction. Refrigerating other medications could cause them to lose their effectiveness because of low temperatures and high humidity. Medication should not be kept in the freezer unless specifically instructed to do so.

Avoid prolonged exposure to sunlight. This means you, not the medication. Certain medications, such as sulfa drugs and tetracyclines, may make you more sensitive to sunlight and tanning lamps, causing you to burn more easily. You should limit exposure to the sun when you are taking these medications. If you skin does become more sensitive, use a sunscreen (SPF 15 or more). Avoid spending a long time in the sun, and wear protective clothing. Report increased sensitivity to your doctor and pharmacist.

May cause discoloration of urine or feces. Some medications may change the color of your urine or stools. This effect is not harmful and will stop when the medication is discontinued. Ask your pharmacist about what to expect. Any unexpected change should be reported to your doctor and pharmacist immediately.

If you wear soft contact lenses, do not wear them during treatment with this type of medication. The medication may discolor your tears, which could permanently stain the contact lenses. Ask your doctor or pharmacist how long to wait after discontinuing the medication before wearing your lenses again.

Shake well. The active ingredient in many liquid medications is in the form of a fine powder, which can settle to the bottom of the bottle. To be sure you receive the correct amount of the active ingredient, shake the bottle vigorously for 15 to 30 seconds every time you take the medication.