الكاتب: Multiple References

Beta2-adrenoceptor agonists are often used in the treatment of obstructive pulmonary diseases. These substances are used to mediate a relaxation of the airway smooth muscles in asthmatic patients with acute bronchial spasm. They are used either locally (as aerosols) or systemically (Rang et al., 1995). In equine medicine, the drug most commonly used is clenbuterol, which is approved in some countries for systemic use as a bronchodilating agent in horses suffering from chronic obstructive pulmonary disease (COPD, heaves). Salbutamol and terbutaline are two b2-stimulating drugs which are commonly used for the treatment of human asthma. The experience of the use of these substances in equine practice is limited. They have been used clinically, but varying dose regimes have been suggested and no pharmacokinetic data are available (Plumb, 1995). In vitro, salbutamol and terbutaline inhibited the contraction of equine tracheal muscle induced by 500 nM carbachol to 80%. Salbutamol was slightly more potent than terbutaline (Hanna & Eyre, 1980).