Pirbuterol (trade name Maxair) is a short-acting β₂ adrenoreceptor agonist with bronchodilating action used in the treatment of

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...

, available (as pirbuterol acetate) as a breath-activated

metered-dose inhaler A metered-dose inhaler (MDI) is a device that delivers a specific amount of medication to the lungs, in the form of a short burst of aerosolized medicine that is usually self-administered by the patient via inhalation. It is the most commonly used ...

. It was patented in 1971 and came into medical use in 1983.

Medical use

Pirbuterol is used in asthma for reversal of acute

bronchospasm Bronchospasm or a bronchial spasm is a sudden constriction of the muscles in the walls of the bronchioles. It is caused by the release (degranulation) of substances from mast cells or basophils under the influence of anaphylatoxins. It causes di ...

, and also as a maintenance medication to prevent future attacks. It should be used in patients 12 years of age and older with or without concurrent

theophylline Theophylline, also known as 1,3-dimethylxanthine, is a phosphodiesterase inhibiting drug used in therapy for respiratory diseases such as chronic obstructive pulmonary disease (COPD) and asthma under a variety of brand names. As a member of the ...

and/or inhaled

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involv ...

Mode of action

Pharmacokinetics

After inhalation of doses up to 800 ''μ''g (twice the maximum recommended dose) systemic blood levels of pirbuterol are below the limit of assay sensitivity (2–5 ng/ml). A mean of 51% of the dose is recovered in urine as pirbuterol plus its sulfate conjugate following administration by aerosol. Pirbuterol is not metabolized by catechol-''O''-methyltransferase. The plasma half-life measured after oral administration is about two hours.

Adverse effects

References

External links

RxList: Maxair (Pirbuterol)
Phenylethanolamines Beta2-adrenergic agonists Pyridines {{respiratory-system-drug-stub