The biggest growth area of the medical industry is the drug business. With so many new and effective prescription drugs on the market, and a number of medications that were once prescription and are now available over the counter, physicians are treating many illnesses with drugs first.

With thousands of drugs on the market, it is reasonable to expect that no doctor can be familiar with all of them, and we must realize that physicians are not always very good about explaining what a drugs do. The result can be drug-drug and/or drug-food interactions.

What can you do?

Have all your prescriptions filled at the same pharmacy so that a history of your medications is on hand and you can be alerted about potential problems. Also, select a drug store that provides an information sheet about each medication, which includes descriptions of what the drug is intended to be taken for, exactly how it should be taken, and possible interactions.

Always ask your doctor what side effects a drug may produce and if any foods should be avoided with the drug. Ask your pharmacist the same questions. And most importantly, read that information sheet to make certain that what both have told you agree. If you notice any unusual symptoms once you begin taking the medication, contact your doctor.

Here are some common reactions to watch out for:

a.. Acetaminophen (Tylenol) and alcohol - usage for long periods of time can cause liver damage

b.. Antacids and broad spectrum antibiotics - antacids can interfere with the body's absorption of tetracycline and certain other broad spectrum antibiotics.

c.. Warfarin (Coumadin) and aspirin - both thin blood and together can lead to uncontrolled bleeding.

d.. Warfarin and anti-inflammatory drugs - Ibuprofen (Advil, Nuprin, Motrin), naproxen (Aleve) and ketoprofen (Orudis) and other nonsteroidal anti-inflammatory drugs can irritate the stomach lining and lead to a bleeding ulcer.

e.. Seldane or Hismanal and ketoconazole (Nizoral) or macrolide antibiotics - together can cause a potentially fatal heart rhythm disturbance.

f.. Anti-inflammatory drugs and alcohol - together can cause stomach irritation or bleeding.

g.. Calcium and antibiotics - calcium and dairy products block absorption of antibiotics.

h.. Dietary fiber and digoxin (Lanoxin) - fiber affects absorption of this drug.

i.. Dietary fiber and tricyclic antidepressants - fiber affects absorption of these drugs.

j.. Grapefruit juice and terfenadine (Seldane) or astemizole (Hismanal) - Grapefruit interferes with liver enzymes that break down this drug. Can cause heart rhythm disturbance.

k.. Grapefruit juice and Plendil, Procardia or Adalat - Grapefruit can increase blood levels of these blood pressure drugs causing headaches, flushing and light-headedness.

l.. Grapefruit juice and warfarin - Grapefruit can increase blood levels of warfarin, increasing risk of bleeding.

m.. Iron and thyroid supplements - the former reduces the effectiveness of the latter.

A little homework before you take that medication can reduce the risk of interactions and/or maximize the effectiveness of that drug.