If you’re battling congestion from a cold or sinus trouble, you probably know that over-the-counter decongestant sprays like Afrin, Dristan, Vicks Sinex, and Zicam (which contain the active ingredient oxymetazoline), usually provide some relief. This drug shrinks swollen nasal tissues quickly, and causes fewer side effects than oral decongestant pills because very little gets absorbed into the bloodstream.

But there is a downside: According to the manufacturers' package labels for these products, nasal sprays shouldn't be used longer than three days. That's because, as the instructions note, using them longer than that increases your risk for a very troubling side effect: rebound nasal congestion, also known as rhinitis medicamentosa.

"Rebound" congestion is when nasal tissue can’t shrink back to its normal size, and instead stays swollen or becomes even further inflamed, says Zara Patel, M.D., assistant professor of otolaryngology at Stanford University and chair of the Education Committee for the American Rhinologic Society.

"Using these sprays long term—months to years—can even lead to something more dangerous called atrophic rhinitis,” warns Patel. “It’s a rare but difficult-to-treat condition marked by uncomfortably dry nasal passages, sometimes with chronic crusting, and in some cases, loss of smell.”

What to Do After Three Days

If you’re using an OTC nasal decongestant spray and still feel stuffy after three days, Marvin M. Lipman, M.D., Consumer Reports' chief medical adviser, recommends switching to pseudoephedrine pills (Sudafed and generic) to lower your rebound congestion risk. Those drugs are often found behind the counter at most pharmacies—you don't need a prescription—but you'll have to purchase the medication directly from a pharmacist.

Some people are sensitive to pseudoephedrine, which is known to cause nervousness, dizziness, or sleeplessness. These side effects are increased when too much of the drug is taken—and in rare cases can even become life-threatening, so don't exceed the recommended dosage. 

It’s important to note that if you have glaucomaheart disease, high blood pressure, an enlarged prostate, or thyroid disease, check with your doctor or pharmacist before using any type of decongestant, even sprays, because they sometimes make those conditions worse.

Try a Saline Rinse

For a safer route to relief that won’t cause rebound symptoms, consider trying nondrug options, such as a saline (salt-based) rinse, before reaching for nasal decongestant sprays and pills, advises Patel.

"Saline rinsing acts in two ways to relieve nasal congestion: It draws out excessive water trapped in your tissues, thereby acting as a natural decongestant, and it rinses away allergens that would otherwise stick to the lining,” she says.

Saline wash is safe to use long term, but since some tap water contains low levels of organisms, such as bacteria and protozoa, it’s best to rinse with bottled, filtered, or distilled water. You can pick up an already-sterilized saline rinse, such as Ayr Saline and Simply Saline, and generic versions, at your drugstore.

Editor's Note: These materials were made possible by a grant from the Attorney General Consumer and Prescriber Education Grant Program, which is funded by a multistate settlement of consumer fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).