Nasal Sprays Can Bring on Vicious Cycle - New York Times:
... It works so well that you tend to keep using it,' says Dr. David Vernick, an ear, nose and throat specialist at Beth Israel Deaconess Medical Center in Boston. 'You're used to breathing well with the spray, and when you stop it, you get congested. So you use it a little more frequently, yet the congestion doesn't clear up for long.'Nyah. It's not that I don't believe in the rebound effect, it's rather that it seems insufficient to explain the range of behaviors seen. I suspect that a small portion of the population develops a true cocaine-like addiction to the decongestant. Anyone who's taken oral sudafed at bedtime knows this class of drugs has stimulant activity. My bet is that a few people metabolize these drugs in a peculiar way, and the result is a truly addictive substance.
That's because after three or four days of continuous use, the sprays can cause the nasal linings to swell up again, even when the cold or attack of sinusitis or allergy that originally caused the problem has passed. If this pattern continues, a patient has a good chance of becoming trapped in a vicious cycle of overuse and dependence that can last for months or years.
Pure speculation. No data.