Counter Intelligence

To use over-the-counter drugs safely, educate yourself about dosage, possible interactions, and even ingredients

Liver damage. Bleeding ulcers. Brain hemorrhages in young women. More bad news about prescription drugs? Not this time. The above problems were all linked to over- the-counter medications we so often take for granted.

About 71% of men and 82% of women in the U.S. have used a nonprescription drug within the past six months, according to a survey by Roper Starch Worldwide. But that doesn't mean we know a lot about them. A 2003 poll by Harris Interactive found only 20% of us bother to check the label for possible side effects. And 77% don't read dosage instructions. "We don't treat them with the same respect as prescription drugs," says Janet Engel, clinical professor of pharmacy at the University of Illinois at Chicago and a spokesperson for the American Pharmacists Assn. on over-the-counter medications. Nonprescription drugs can be just as strong as prescription ones, she says. In fact, half or more of them used to be just that, according to Larry Sasich, a pharmacist and research analyst with Public Citizen, a public interest group.

Generally, the Food & Drug Administration approves drugs for over-the-counter use only after they have been on the market for years, with good safety records, and if they are considered easy for lay persons to use without medical supervision. In short, the drugs are thought to carry little risk if taken as directed. Still, "there is no such thing as a risk-free medication," explains Dr. Joseph Lau, an internist and professor of medicine at Tufts University School of Medicine. A cavalier attitude about ingredients, dosage, possible drug interactions, and adverse side effects can be dangerous.

ULCER TROUBLE

Only a few years ago phenylpropanolamine was a common ingredient in cold remedies and diet aids. Manufacturers withdrew it from the market after a Yale University School of Medicine study found an increased incidence of brain hemorrhage among women soon after they took the medication. Many people know high doses of aspirin can cause bleeding ulcers. But how many are aware that large doses (generally more than 2.5 times the recommended maximum of 4 grams per day) of Tylenol can cause liver damage? Regular drinkers may be at risk even if they stay within the recommended dosage, says Dr. Keith Lindor, a hepatologist at the Mayo Clinic in Rochester, Minn.

Reading over-the-counter drug labels -- most of which were set to be updated, under FDA order, by May 16 to provide clearer, more consistent information -- can be critical. The label lists active and inactive ingredients, the symptoms the drug should be used to treat, the appropriate dosage, and warnings about possible side effects as well as activities and other medications to avoid while taking the drug.

Knowing the ingredients is critical since many over-the-counter remedies contain the same drug, making it easy to take more than you need. Someone using NyQuil for a cold who decides to add some Tylenol for a sinus headache will get a double dose of acetaminophen, since both products contain it. Taking Sominex in hopes of getting a good night's sleep despite your allergies will make you extra drowsy if you're using Benadryl for your stuffy nose and watery eyes. Diphenhydramine is in both.

It's important to check the label, too, because the medication may contain some surprising ingredients. Engel tells of a patient who came to her pharmacy asking for something to help her sleep. Turns out she was taking Excedrin, which contains caffeine, for her arthritis pain. "This patient didn't need something to make her sleep," says Engel. "She just needed to stop taking the medication that was keeping her up."

Even "inactive ingredients" used as fillers or to make a tablet dissolve properly can cause problems. In fact, says Robert Osterberg, an FDA pharmacologist, the deaths of more than 100 children in the 1930s from an additive used to sweeten an antibacterial drug led to the nation's first law mandating safety testing of drugs before they are marketed. The additive? Diethylene glycol, the ingredient in antifreeze. Those with allergies need to be especially vigilant. Some dyes used to color medicines have been suspected in allergic reactions. The lactose-intolerant might want to check labels for that milk sugar. And patients with hard-to-control diabetes should avoid products containing sucrose, or sugar.

Anyone with a serious medical condition such as heart or kidney trouble should consult a doctor before taking nonprescription medication. That's because the medication could interact with drugs they are already taking or worsen their condition. Antihistamines can cause problems for glaucoma patients by interfering with drainage of eye fluid, Dr. Lau says, while men with enlarged prostates may have more difficulty urinating. If you're considering taking more than one over-the-counter medication at the same time, at least confer with your pharmacist.

Cold remedies are a particular sore point with Sasich, the Public Citizen research analyst. Many people grab the one that promises relief for every cold symptom known to man, rather than targeting their particular symptoms. If all you have is a runny nose, all you need is an antihistamine. Those who take something containing a decongestant, cough suppressant, and pain reliever are overmedicating. Remember, all those extras come with their own side effects. Oral decongestants, Sasich says, can raise blood pressure. Antihistamines affect the central nervous system and can cause poor memory and difficulty thinking. Older patients who routinely use them might be misdiagnosed as having dementia, he says. Sasich -- something of a purist -- recommends buying a separate syrup for each symptom, then taking more than one if you have multiple symptoms.

It's also important to know when to stop using an over-the-counter drug. If you're guzzling cough syrup and your cough persists more than a week or so, see a doctor to rule out a more serious condition, such as pneumonia or even lung cancer.

Finally, as you survey the wide array of over-the-counter offerings, remind yourself that many of them started out as prescription drugs. So show some respect.

By Carol Marie Cropper

    Before it's here, it's on the Bloomberg Terminal.
    LEARN MORE