Metabolism of propanoate begins with its conversion to propionyl coenzyme A (propionyl-CoA), the usual first step in the metabolism of carboxylic acids. Since propanoic acid has three carbons, propionyl-CoA can directly enter neither beta oxidation nor the citric acid cycles. In most vertebrates, propionyl-CoA is carboxylated to D-methylmalonyl-CoA, which is isomerised to L-methylmalonyl-CoA. A vitamin B 12 -dependent enzyme catalyzes rearrangement of L-methylmalonyl-CoA to succinyl-CoA, which is an intermediate of the citric acid cycle and can be readily incorporated there.
In the 12-month, open-label, active-controlled, long-term safety trial in adults and adolescents 12 years of age and older, 404 patients with perennial allergic rhinitis or vasomotor rhinitis were treated with DYMISTA 1 spray per nostril twice daily and 207 patients were treated with fluticasone propionate nasal spray, 2 sprays per nostril once daily. Overall, adverse reactions were 47% in the DYMISTA treatment group and 44% in the fluticasone propionate nasal spray group. The most frequently reported adverse reactions ( ≥ 2%) with DYMISTA were headache, pyrexia, cough, nasal congestion, rhinitis, dysgeusia, viral infection, upper respiratory tract infection, pharyngitis, pain, diarrhea, and epistaxis. In the DYMISTA treatment group, 7 patients (2%) had mild epistaxis and 1 patient ( < 1%) had moderate epistaxis. In the fluticasone propionate nasal spray treatment group 1 patient ( < 1%) had mild epistaxis. No patients had reports of severe epistaxis. Focused nasal examinations were performed and no nasal ulcerations or septal perforations were observed. Eleven of 404 patients (3%) treated with DYMISTA and 6 of 207 patients (3%) treated with fluticasone propionate nasal spray discontinued from the trial due to adverse events.
A twelve month study (Gaining Optimal Asthma ControL, GOAL), in 3416 adult and adolescent patients with persistent asthma, compared the safety and efficacy of Seretide versus inhaled corticosteroid (Fluticasone Propionate) alone to determine whether the goals of asthma management were achievable. Treatment was stepped up every 12 weeks until ** total control was achieved or the highest dose of study drug was reached. GOAL showed more patients treated with Seretide achieved asthma control than patients treated with ICS alone and this control was attained at a lower corticosteroid dose.