Orciprenaline also known as metaproterenol is a bronchodilator used in the treatment of asthma. Orciprenaline is a moderately selective beta2-adrenergic receptor agonist that stimulates receptors of the smooth muscle in the lungs, uterus, and vasculature supplying skeletal muscle, with minimal or no effect on alpha-adrenergic receptors. The pharmacologic effects of beta adrenergic agonist drugs, such as orciprenaline, are at least in part attributable to stimulation through beta adrenergic receptors of intracellular adenyl cyclase, the enzyme which catalyzes the conversion of ATP to cAMP. Increased cAMP levels are associated with relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from many cells, especially from mast cells.

Pirbuterol commercially available as Maxair is a beta-2 adrenergic bronchodilator used in the treatment of asthma, available (as perbuterol acetate) as a breath-activated metered-dose inhaler. MAXAIR AUTOHALER is a pressurized metered-dose aerosol unit for oral inhalation. It provides a fine-particle suspension of maxair acetate in the propellant mixture of trichioro-monofluoromethane and dichlorodifluoromethane, with sorbitan trioleate. Each actuation delivers 253 mcg of maxair (as maxair acetate) from the valve and 200 mcg of maxair (as maxair acetate) from the mouthpiece. The unit is breath-actuated such that the medication is delivered automatically during inspiration without the need for the patient to coordinate actuation with inspiration.

Maxair is used to treat wheezing and shortness of breath that commonly occur with lung problems (e.g., asthma, chronic obstructive pulmonary disease-COPD). Controlling these symptoms can decrease time lost from work or school. maxair is a bronchodilator (beta-2 receptor agonist) that works by opening breathing passages to make breathing easier. This medicine comes in an inhaler that automatically releases a puff of medicine when you inhale. The inhaler allows the drug to reach deep into the lungs for the most benefit. Because this type of inhaler is used differently than other types, be sure to follow directions closely.

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Indacaterol is an ultra long acting beta-adrenoceptor agonist currently undergoing research. It needs only be taken once a day, unlike the currently available Formoterol and Salmeterol. Such drugs are used in the treatment of chronic obstructive pulmonary disease and asthma.

Indacaterol by Novartis is an effective and well-tolerated treatment of asthma and chronic obstructive pulmonary disease (COPD) over 24 hours with a rapid onset of action. The combination of 24-hour efficacy and a reassuring safety profile suggests that in time, a once-daily dose of indacaterol could become a new standard of care for bronchodilation in asthma and COPD. Indacaterol could be the first beta2-agonist to be taken only once-daily providing full 24 hour symptom control with a single administration, in contrast to currently-available long-acting beta2-agonists (LABAs) such as salmeterol and formoterol which have to be taken twice-daily.

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Xopenex as a bronchodilator is used to treat asthma and COPD. In general, xopenex has similar pharmacokinetic and pharmacodynamic properties to albuterol; however, its manufacturer, Sepracor, has implied (although not directly claimed) that the presence of only the R-enantiomer produces fewer side effects.

Physicians sometimes elect to use xopenex in patients with a history of supraventricular tachycardia or other arrhythmias because it is thought that xopenex may produce less direct effects on beta-adrenergic receptors in the heart. For similar reasons, some pediatricians also use xopenex for patients who experience hyperactivity or jitteriness from racemic albuterol.

The use of xopenex over the more traditionally used racemic albuterol is controversial among health care professionals. That using xopenex instead of albuterol produces less direct effect on beta adrenergic receptors and/or fewer cardiac side effects has been suggested, but not consistently demonstrated by long term, well-designed clinical trials.

There are differing opinions on whether there is sufficient therapeutic benefit to using xopenex that outweighs the 5-10 times higher price tag. In general, it appears that if a clinician and patient feel that a low dose of racemic mixture is causing undesirable side effects, xopenex may be a viable alternative. xopenex was originally available only as a solution for nebulizer and eventually become available as a CFC-free metered dose inhaler under the trade name Xopenex HFA (xopenex tartrate) Inhalation Aerosol.

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