Inhaled corticosteroids (ICS) is the gold standard prophylactic therapy for patients with persistent asthma. In the setting of acute asthma exacerbation systemic steroids given early in the course of treatment help decrease the rate of admission and return to the ER. However, the anti-inflammatory action of corticosteroids, through which this effect is caused, takes 4 hours to start working. This is because it is mediated through genomic pathways where the transcription of several inflammatory cytokines is suppressed. It was also shown that corticosteroids can cause vasoconstriction through non-genomic pathways. The onset of this action is as quick as 30-60 minutes. It is proposed that this action is mediated by blocking the extraneuronal uptake (metabolism) of norepinephrine in vascular smooth muscle cells, hence, making it available for re-use by the sympathetic neuronal cells.