The problem:
More than a half-million people end up in the emergency room each year from adverse reactions to their prescription medications, according to the Centers for Disease Control and Prevention.

What you need to know:
Don’t mix over-the-counter medications, supplements or herbal products with prescriptions (or with each other) without running it by all your doctors.

The health product: Pain relievers

The problem:
Over-the-counter pain-reliever misuse leads to more than 16,000 U.S. deaths a year, according to the National Consumers League.

What you need to know:
The FDA recently proposed adding warning labels to OTC pain relievers, but educate yourself in the meantime. With products that contain acetaminophen, such as Tylenol, exceeding the recommended dosage, combining the drug with other acetaminophen products (it’s found in hundreds of cough, cold, allergy and sinus medications) or with three or more drinks of alcohol a day can cause serious liver problems. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen and ibuprofen can cause stomach ulcers, upset stomach and life-threatening stomach bleeding if combined with other NSAIDs, consumed with alcohol or taken longer than recommended. Know what you are taking and how much of it is safe.

The health product: Decongestant nasal sprays

The problem:
Over-the-counter nasal sprays might relieve a stuffy nose, but you can become dependent on them, and they may make symptoms worse for some sinus sufferers.

What you need to know:
Stop using the spray after four days. Otherwise, your nasal passages can develop a tolerance to it and you might require larger, more frequent dosages. If you need relief after four days, discuss other treatment options, such as oral decongestants, with your doctor.

The health product: Eye whitening drops

The problem:
These drops are a quick fix for red eyes, but are not intended for daily use.

What you need to know:
Eye whitening drops contain an ingredient that reduces the blood flow to the outermost part of your eyes, which short-circuits your body’s natural defense to irritants. Long-term use can mask a health problem or cause a rebound effect, making your eyes even more red upon application. If you’re frequently treating dry eyes (for conditions you’re aware of, like seasonal allergies), opt for a moisturizing product such as Rite Aid Artificial Tears, $4, Rite Aid, instead. Otherwise, make an appointment to see your optometrist to find out what’s causing the irritation.