['In clinical trials, only about 60% of subjects report an excellent response to intranasal steroids, suggesting a need to add therapies to intranasal steroids to provide additional efficacy.', 'To determine whether the combination of fluticasone furoate and oxymetazoline is more efficacious than either agent alone, and to determine whether rhinitis medicamentosa develops after treatment.', 'We performed a double-blind, double-dummy, randomized, placebo-controlled parallel study. Sixty patients with perennial allergy were randomized to 4 weeks of once-a-night treatment with fluticasone furoate, oxymetazoline hydrochloride, the combination, or placebo. They were monitored during treatment and for 2 weeks posttreatment.', 'The total nasal symptom score over the 4 weeks of treatment was lower with the combination (median, 143; range, 30-316) compared with treatment with placebo (262; 116-358) and oxymetazoline alone (219; 78-385; ANOVA, P = .04). When acoustic rhinometry was compared between the groups at the end of 4 weeks of treatment, the combination resulted in significantly higher nasal volume (mean + SEM, 15.8 + 1.1 mL; P< .03) compared with both placebo (12.1 + 0.9 mL) and oxymetazoline (12.4 + 0.8 mL) alone. The quality of life data showed no significant differences among the groups. Peak flow showed a nonsignificant improvement with the groups on fluticasone furoate. There was no evidence of rhinitis medicamentosa.'] Does oxymetazoline add to the effectiveness of fluticasone furoate in the treatment of perennial allergic rhinitis?