Enantiomer-specific effects of albuterol on airway inflammation in healthy and asthmatic cats.
July 4, 2018 11:12 am
Reinero et al. discuss the hypothesis that regular administration of R,S-albuterol or S-albuterol, but not R-albuterol, would induce airway inflammation in healthy and asthmatic cats.
Racemic (R,S)-albuterol is a 1:1 mixture of an R-enantiomer which has bronchodilatory and anti-inflammatory effects, and an S-enantiomer which is associated with increased airway hyperreactivity and proinflammatory effects. Proinflammatory effects of regularly inhalated and S-albuterol have not been studied in a whole-animal model.
Healthy and asthmatic cats receiving R,S- and S-albuterol had higher total lavage cell numbers (p = 0.04 and p = 0.02, respectively) than those receiving R-albuterol and placebo. The number of lavage eosinophils and the TNF-alpha bioactivity was higher in asthmatic cats receiving R,S- and S-albuterol compared with those receiving the other treatments (p = 0.03 and p = 0.004, respectively). In healthy cats, the number of lavage neutrophils was higher when they received R,S- and S-albuterol compared with other treatments (p = 0.04)
They conclude that airway inflammation is induced in both healthy and asthmatic cats with regular inhalation of racemic and S-albuterol, but not with R-albuterol.
This is important as widely used commercial versions of albuterol (salbutamol, Ventolin) are of racemic formulation. Frequent use of a bronchodilator in cats without the use of an inhaled corticosteroid may further exacerbate existing airway inflammation.
Int Arch Allergy Immunol. 2009;150(1):43-50