Sepracor in the US is developing arformoterol [R,R-formoterol], a single isomer form of the beta(2)-adrenoceptor agonist formoterol [eformoterol]. This isomer contains two chiral canters and is being developed as an inhaled preparation for the treatment of respiratory disorders. Sepracor believes that arformoterol has the potential to be a once-daily therapy with a rapid onset of action and a duration of effect exceeding 12 hours. Sepracor stated in July 2003 that it had completed more than 100 preclinical studies and initiated or completed 15 clinical studies for arformoterol inhalation solution for the treatment of bronchospasm in patients with COPD. The pharmacologic effects of beta2-adrenoceptor agonist drugs, including arformoterol, are at least in part attributable to stimulation of intracellular adenyl cyclase, the enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3′,5′-adenosine monophosphate (cyclic AMP). Increased intracellular cyclic AMP levels cause relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from mast cells. In vitro tests show that arformoterol is an inhibitor of the release of mast cell mediators, such as histamine and leukotrienes, from the human lung. Arformoterol also inhibits histamine-induced plasma albumin extravasation in anesthetized guinea pigs and inhibits allergen-induced eosinophil influx in dogs with airway hyper-responsiveness. The relevance of these in vitro and animal findings to humans is unknown.

Formoterol is a long-acting selective beta2-adrenergic receptor agonist (beta2-agonist). Inhaled formoterol fumarate acts locally in the lung as a bronchodilator. In vitro studies have shown that formoterol has more than 200-fold greater agonist activity at beta2-receptors than at beta1- receptors. Although beta2-receptors are the predominant adrenergic receptors in bronchial smooth muscle and beta1-receptors are the predominant receptors in the heart, there are also beta2-receptors in the human heart comprising 10%-50% of the total beta-adrenergic receptors. The precise function of these receptors has not been established, but they raise the possibility that even highly selective beta2- agonists may have cardiac effects. The pharmacologic effects of beta2-adrenoceptor agonist drugs, including formoterol, are at least in part attributable to stimulation of intracellular adenyl cyclase, the enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3', 5'-adenosine monophosphate (cyclic AMP). Increased cyclic AMP levels cause relaxation of bronchial smooth muscle and inhibits the release of pro-inflammatory mast-cell mediators such as histamine and leukotrienes. Formoterol also inhibits histamine-induced plasma albumin extravasation in anesthetized guinea pigs and inhibits allergen-induced eosinophil influx in dogs with airway hyper-responsiveness. The relevance of these in vitro and animal findings to humans is unknown. Formoterol is used for use as long-term maintenance treatment of asthma in patients 6 years of age and older with reversible obstructive airways disease, including patients with symptoms of nocturnal asthma, who are using optimal corticosteroid treatment and experiencing regular or frequent breakthrough symptoms requiring use of a short-acting bronchodilator. Not indicated for asthma that can be successfully managed with occasional use of an inhaled, short-acting beta2-adrenergic agonist. Also used for the prevention of exercise-induced bronchospasm, as well as long-term treatment of bronchospasm associated with COPD. Marketed as Foradil Aerolizer.

Budesonide is a glucocorticoid used in the management of asthma, the treatment of various skin disorders, allergic rhinitis and ulcerative colitis. The precise mechanism of corticosteroid actions on inflammation in asthma is not well known. Inflammation is an important component in the pathogenesis of asthma. Corticosteroids have been shown to have a wide range of inhibitory activities against multiple cell types (e.g., mast cells, eosinophils, neutrophils, macrophages, and lymphocytes) and mediators (e.g., histamine, eicosanoids, leukotrienes, and cytokines) involved in allergic- and non-allergic-mediated inflammation. The anti-inflammatory actions of corticosteroids may contribute to their efficacy in asthma. Commonly reported side effects of budesonide include: acne vulgaris, moon face, and bruise. Other side effects include: ankle edema, hirsutism, weakness, arthralgia, nausea, and rhinitis. Ketoconazole, a potent inhibitor of cytochrome P450 (CYP) isoenzyme 3A4 (CYP3A4), the main metabolic enzyme for corticosteroids, increased plasma levels of orally ingested budesonide.

Beclometasone dipropionate or beclomethasone dipropionate is sold under the brand name Qvar among others. Beclomethasone dipropionate is a corticosteroid demonstrating potent anti-inflammatory activity. The precise mechanism of corticosteroid action on asthma is not known. Corticosteroids have been shown to have multiple anti-inflammatory effects, inhibiting both inflammatory cells (e.g., mast cells, eosinophils, basophils, lymphocytes, macrophages, and neutrophils) and release of inflammatory mediators (e.g., histamine, eicosanoids, leukotrienes, and cytokines). These anti-inflammatory actions of corticosteroids may contribute to their efficacy in asthma. Beclomethasone dipropionate is a prodrug that is rapidly activated by hydrolysis to the active monoester, 17 monopropionate (17-BMP). Beclomethasone 17 monopropionate has been shown in vitro to exhibit a binding affinity for the human glucocorticoid receptor, which is approximately 13 times that of dexamethasone, 6 times that of triamcinolone acetonide, 1.5 times that of budesonide and 25 times that of beclomethasone dipropionate. The clinical significance of these findings is unknown. Studies in patients with asthma have shown a favorable ratio between topical anti-inflammatory activity and systemic corticosteroid effects with recommended doses of QVAR. Beclometasone dipropionate was first patented in 1962 and used medically in 1972. Common side effects with the inhaled form include respiratory infections, headaches, and throat inflammation. Serious side effects include an increased risk of infection, cataracts, Cushing’s syndrome, and severe allergic reactions. Long term use of the pill form may cause adrenal insufficiency. The pills may also cause mood or personality changes. The inhaled form is generally regarded as safe in pregnancy. Beclometasone is mainly a glucocorticoid.

Aclidinium is a long-acting, competitive, and reversible anticholinergic drug that is specific for the acetylcholine muscarinic receptors. It binds to all 5 muscarinic receptor subtypes to a similar affinity. It has a much higher propensity to bind to muscarinic receptors than nicotinic receptors. FDA approved on July 24, 2012. Aclidinium's effects on the airways are mediated through the M3 receptor at the smooth muscle to cause bronchodilation. Prevention of acetylcholine-induced bronchoconstriction effects was dose-dependent and lasted longer than 24 hours.