Yes, the onset of effect of Symbicort is faster than that of Seretide (fixed combination salmeterol/fluticasone). This was confirmed in a double-blind, crossover, placebo-controlled trial involving 30 patients with asthma (Palmqvist et al, 2001) in which the onset of effect of both doses of Symbicort was significantly (p < 0.001) faster than that of Seretide when measured by:
•FEV1 at 3 minutes
•average FEV1 from 0–15 minutes

In this study, Symbicort also showed superiority to Seretide as measured by:both doses resulted in higher FEV1 at 3 hours than Seretide (Symbicort 2 inhalations vs Seretide, p<0.001; Symbicort 1 inhalation vs Seretide, ns)average FEV1 for the entire 3-hour period (Symbicort 1 and 2 inhalations vs Seretide, p<0.001)maximal FEV1 for the entire 3-hour period (Symbicort 1 and 2 inhalations vs Seretide, p<0.001)

Results from Palmqvist 2001 showed that Symbicort improves lung function as early as within 3 minutes, an onset of effect comparable to traditional reliever medications. In a direct comparison, the onset of effect of the long-acting ß2-agonist component of Symbicort, formoterol, was found to be as rapid as that of salbutamol (Seberová, 2000). Patients noticed the fast onset of effect
of formoterol in the same way as they would with the effects of short-acting ß2-agonists (Politiek, 1999).

Formoterol: onset of effect similar to salbutamol

The rapid onset of effect with Symbicort may have advantages in overcoming the potential problem of over-reliance on relief medication at the expense of anti-inflammatory medication resulting in poor asthma control.