Medications work best when you take them as directed and understand how they interact with your life. Learn all you can about the medications you're prescribed.

"Don't be afraid to ask questions," says Dr. Michael Fossler, a public policy expert with the American College of Clinical Pharmacology. Here are key questions he suggests you take up with your doctor or pharmacist with every prescription filled.

Do I take this with food?

Some medications need to be taken with food, some should be taken while fasting, and for others it doesn't matter. Ask if you should wait a certain amount of time before or after eating.

Are there any foods I should avoid while taking this?

Some foods can alter the way a medication works. Grapefruit juice is probably the best known example. The citrus affects the way the body absorbs medication.

If taking antibiotics, ask if you should monitor your intake of milk and dairy products. If you drink alcohol, find out if you should refrain from drinking while taking your medication.

What are the side effects?

All medicines have side effects. You'll want to know the most common ones are, as well as the most alarming ones. Ask these questions:

• Do I need to be careful in the sun?
• Will this affect my ability to drive?
• Will this change my mood?
• Should I avoid caffeine?

"If you're running into a side effect you don't care for, don't stop taking the medicine," Dr. Fossler says. "Go back to your doctor's office and tell them you can't tolerate this side effect."

What about other medications?

Tell your doctor or pharmacist about every medication you take, as well as herbal or dietary supplements, allergy medicines, and even a daily aspirin. Be as specific as you can.

Can I stop taking this if I feel better?

Taking your medication as prescribed for the full duration is very important, particularly with antibiotics and disease medications. "With antibiotics, if you stop taking your meds when you start to feel better, your infection can rebound and you'll need a stronger drug next time," Dr. Fossler says. Consult with your primary care physician if you are thinking about quitting your medication — or if you can't afford it. Your doctor or pharmacist may know of ways to help you save money on your prescription medications.