Mechanism of Actions

• Anticholinergic bronchiodilators

  Delivery: inhaled

  Block acetylcholine receptors which cause brochodilation by preventing bronchoconstriction / bronchospasm
• Leukotriene Inhibitors

  Delivery: oral

  These tablet medications inhibit leukotriene receptors or the enzyme lipoxygenase that converts free arachadonic acid to leukotrienes in the inflammtory cascade.

  They are used in patients with an allergic component to their asthma
• Selective Beta-2 Adrenergic Agonist Bronchiodilators

  Delivery: inhaled

  Sympathetic stimulation results in bronchodilation by relaxing bronchiolar smooth muscle. Other adrenergic medications will cause bronchiodilation but also stimulate cardiovascular effects. Selective B-2 agonists allow selective stimulation of the adrenergic receptors in the lungs.
• Glucocorticoids

  Delivery: inhaled, oral, or IV

  These meds work at the gene expression level of inflammatory mediators and block phospholipase A2 at the top of the inflammatory cascade, thus preventing leukotriene and prostaglandin formation. They act by reducing airway inflammation.

  Acute care: meds given by IV, then orally. Chronic use of oral steroids is decreasing.

  Systemic side effects with inhaled steroids are not as severe
• Cromones

  Delivery: inhaled

  Inhibits release of inflammatory mediators in the respiratory mucosa (mast cell stabilizer)

  Not used as a rescue inhaler
• Xanthine bronchodilators

  Act within bronchial smooth muscle cells

  Inhibits smooth muscle contraction