Xylometazoline (Neo-Rinoleina; Novorin; Olynth; Otriven; Otrivin; Otrivine; Xymelin) is a topical decongestant that is directly dosed into the nose, either as a spray or as drops.

Xylometazoline is marketed under the brand names Otrivine or Otrivin, with the standard adult dose being 0.1% w/v xylometazoline. The dose for children under 12 is 0.05%.

The drug works by constricting the blood vessels in the nose. The vasoconstriction means that there is less pressure in the capillaries and less water can filter out, thus less discharge is made. (If the colour of the nasal passage is observed, it is visibly paler after dosage.)

Xylometazoline is designed to mimic the molecular shape of adrenaline meaning that it binds to the same cell receptors adrenaline does. For this reason, it should not be used by people with high blood pressure, or other heart problems. (It acts mainly on alpha-adrenergic receptors.)

Unfortunately the vessels become resistant to the drug after prolonged dosing. The number of receptors decreases, and when the administration of the drug is ceased, chronic congestion can occur; this is called rhinitis medicamentosa, commonly referred to as rebound congestion. Moreover long-term overdosing can cause degenerative changes in nasal mucous membranes that pose another health problem.