Experts offer these guidelines for buying and using prescription drugs:

* Ask questions of your doctor, your dentist and your pharmacist about the drugs prescribed in your treatment.

* Take your medicine according to the schedule printed on its label. If you miss a dose, don't catch up by doubling the next one without consulting your doctor or pharmacist. The timing of your doses can have an important effect on the success of the treatment.

* If you don't like taking pills, ask if the drug you've been prescribed comes as a liquid. Some tablets can be crushed in water or juice. Others shouldn't be dissolved because the coating is designed to regulate the rate at which the drug is absorbed. If you have difficulty swallowing pills, ask your pharmacist for suggestions. You may have to get your doctor to write a new prescription for a new form of the medicine.

* Establish a patient profile record with a pharmacist. This up-to-date list of the medicines you take -- including over-the-counter products -- can help you avoid drug interaction problems.

* Ask if your medicine could interfere with accurate results on any medical tests you may have scheduled.

* Don't take prescription medicine that belongs to someone else, or share your medicine with someone else -- no matter how similar your symptoms may seem.

* Don't mix drugs and alcohol. Don't expect a medicine to make you feel better instantly. If you feel the medicine is ineffective, call your doctor.

* Don't stop taking your medicine after a day or two, even if you feel better. Stopping too soon may lead to a later flare-up of the original problem.

* Don't carry daily doses of medicines in your own pillboxes. The tablets may break, reducing the correct dosage. The drugs may interact with the pillbox material -- nitroglycerin can be absorbed by certain plastics, for example. Certain metals can effect other drugs. Ask your pharmacist how your pills can be carried conveniently.

* Don't assume that your bathroom medicine chest is the right place to keep your drugs. The moisture from the bathtub and shower may cause them to deteriorate. Ask your pharmacist how specific medicines should be stored.

* Don't drive or operate machinery if you are taking a medicine that makes you drowsy -- whether it's a prescription or an over-the-counter preparation.