The efficacy of fluticasone propionate aqueous nasal spray (0.05% w/w) in the treatment of rhinitis medicamentosa has been studied in an animal model (guinea pig). Rhinitis medicamentosa was induced through the instillation of 0.05% naphthazoline nitrate (Privine) for 8 weeks. Fluticasone propionate nasal spray was then administered to the animals for 2 weeks. The spray successfully cleared the interstitial edema which is the pathologic hallmark of rhinitis medicamentosa. The study suggests that fluticasone propionate nasal spray can be beneficial in the treatment of patients with rhinitis medicamentosa.