|Reviewed & Approved by Clinical practice Committee|
Salbutamol solution for nebulization is available in PICU or ED, the intravenous preparation is available in NICU.
The mechanism of action of salbutamol is not yet completely understood. Salbutamol binds the β2 adrenoceptor with relatively low affinity but moderate efficacy and behaves largely as an agonist. It has a relatively short half-life due to rapid re-equilibration of the drug at the active site with limited residency time. β2 adrenoceptor activation leads to an increase of intracellular cAMP and activation of protein kinase A leading to smooth muscle relaxation. Protein kinase A also activates the Na / K ATPase, facilitating transport of K+ across the cell membrane into the cell and stabilization of the membrane potential.3,4
Less than 5% of aerosol particles reach the lung if given via face mask or endotracheal tube, respectively.(5–7) Some proportion of the aerosol may be swallowed and readily absorbed from the gastrointestinal tract. First pass metabolism of salbutamol occurs in the liver. About half is excreted in the urine as an inactive sulphate conjugate, and about 30% is excreted as unchanged salbutamol.
Bronchodilatation usually starts within 3-5 minutes with peak at 15-20 minutes. The duration of effect is approximately 4 hours.
Studies suggest that in ventilator dependent preterm infants, salbutamol
nebulization facilitated a short lasting decrease in respiratory system
resistance and an improvement in respiratory system compliance. However,
salbutamol does not seem to be effective in preventing long term sequelae such
as BPD and/or death.(8)