Post-drug rhinitis is associated with long-term (>10 days) topical use of vasoconstrictors in the nasal mucosa, imidazole derivatives (oxymetazoline, xylometazoline) or sympathicomimetic amines (ephedrine, psuedoephedrine, phenylephrine). Chronic use of these drugs reduces receptor sensitivity and is responsible for unresponsiveness to previously used and relieving decongestants (tachyphylaxis phenomenon), increased nasal mucosal oedema and impaired nasal permeability. Alpha-mimetic drugs inhibit the production of endogenous norepinephrine, which is associated with weaker vasoconstriction, and, in addition to alpha receptors, stimulate beta receptors, leading to vasodilation and increased oedema.

In adults and adolescents, drug-induced rhinitis can occur after antihypertensive drugs, contraceptives, non-steroidal anti-inflammatory drugs, psychotropic drugs or phosphodiesterase inhibitors. It also occurs in drug users. Therapy involves gradual discontinuation of shrinking drugs with concomitant intranasal administration of steroids for at least six weeks. If there are no effects of steroid treatment, topical antihistamines are recommended for at least 6 weeks and, if there is still no improvement, a short 5-7 day oral steroid therapy.