Rhinitis medicamentosa

Rhinitis medicamentosa (or RM) is a condition of rebound nasal congestion brought on by extended use of topical decongestants (e.g. oxymetazoline, phenylephrine, and xylometazoline nasal sprays) that work by constricting blood vessels in the lining of the nose. This condition typically occurs after 5 to 7 days of use of such medications. Patients often try increasing both the dose and the frequency of nasal sprays upon the onset of RM, worsening the condition. The swelling of the nasal passages caused by rebound congestion may eventually result in polyps that block nasal breathing until surgically removed.

Topical nasal sprays act as an agonist to sympathetic α1 receptors in the blood vessels of the nose, signaling those vessels to contract. By decreasing blood flow to the lining of the nose, the tissue becomes less congested and mucous production is slowed. However, after several days use of these products these receptors become downregulated requiring more frequent and higher doses to prevent the rebound congestion that results when the medicine wears off.

The treatment of RM involves withdrawal of the offending nasal spray. Both a "cold turkey" and a "weaning" approach can be used. Symptoms of congestion and runny nose can often be temporized by using prescription nasal steroid sprays 1 to 2 times daily for a few weeks. For very severe cases oral steroids may be necessary. Oral decongestant medications like pseudoephedrine can also help with the transition.

Other commercially available products such as Rhinostat may help ease withdrawal from physiological tolerance to the nasal decongestant by providing an easy means to dilute the spray gradually.

A study has shown that the anti-infective agent benzalkonium chloride, which is frequently added to topical nasal sprays, aggravates the condition by further increasing the rebound swelling.

Common issues that lead to overuse of topical decongestants:
 * Deviated septum
 * Upper respiratory tract infection
 * Vasomotor rhinitis
 * Cocaine abuse
 * Pregnancy (these products are not considered safe for pregnancy, however)
 * Chronic rhinosinusitis
 * Hypertrophy of the Inferior Turbinates