and the Nursing Process 10th
Edition By Linda Lilley, Shelly
Collins, Julie Snyder Chapter 1-58
|Complete Guide
bronchodilators overview
Bronchodilators are an important part of the pharmacotherapy for all
respiratory diseases. These drugs relax bronchial smooth muscle, which
causes dilation of the bronchi and bronchioles that are narrowed as a result
of the disease process. There are three classes of such drugs: beta
adrenergic agonists, anticholinergics, and xanthine derivatives.
beta andregenic drug overview
The beta-adrenergic agonists are a group of drugs that are commonly used
during the acute phase of an asthmatic attack to quickly reduce airway
constriction and restore airflow to normal. They are agonists of the
adrenergic receptors in the sympathetic nervous system. The beta and alpha
adrenergic receptors are discussed in Chapters 18 and 19. The beta agonists
imitate the effects of norepinephrine on beta receptors. For this reason, they
are also called sympathomimetic bronchodilators. The beta agonists are
categorized by their onset of action. Short-acting beta agonist (SABA)
inhalers include albuterol (Ventolin), levalbuterol (Xopenex), pirbuterol
(Maxair), terbutaline (Brethine), and metaproterenol (Alupent). Long-acting
beta agonist (LABA) inhalers include arformoterol (Brovana), formoterol
(Foradil, Perforomist), and salmeterol (Serevent). The newest long-acting
beta agonists are indacterol (Arcapta Neohaler); vilanterol in conjunction with
fluticasone (Breo Ellipta); and vilanterol in conjunction with the
anticholinergic umeclidinium (Anoro Ellipta). The term Ellipta refers to a new
delivery system. Because the long-acting beta agonists (LABAs) have a
longer onset of action, they must never be used for acute treatment. Patients
,must be taught to use the short-acting beta agonist (SABA) as rescue
treatment.
short acting beta agonist
albuterol (Ventolin), levalbuterol (Xopenex), pirbuterol (Maxair), terbutaline
(Brethine), and metaproterenol (Alupent).
Albuterol
Class : beta 2 agonist (short acting)
Indications and mechanisms of action: is a short-acting beta2-specific
bronchodilating beta agonist. Other similar drugs include bitolterol
(Tornalate), levalbuterol (Xopenex), pirbuterol (Maxair), and terbutaline
(Brethine). Albuterol is the most commonly used drug in this class. If
albuterol is used too frequently, dose-related adverse effects may be seen,
because albuterol loses its beta2-specific actions, especially at larger
dosages
Contraindications :. As a consequence, the beta1 receptors are stimulated,
which causes nausea, increased anxiety, palpitations, tremors, and an
increased heart rate.
Route: po and inhalation
,Other facts: levorotatory isomeric form of albuterol, levalbuterol, is
sometimes prescribed as an albuterol alternative for patients with certain
risk factors (e.g., tachycardia, including tachycardia associated with albuterol
treatment). (Lilley 583)
Lilley, Linda, Shelly Collins, Julie Snyder. Pharmacology and the Nursing
Process, 8th Edition. Mosby, 022016. VitalBook file.
long acting beta agonist
arformoterol (Brovana), formoterol (Foradil, Perforomist), and salmeterol
(Serevent). The newest long-acting beta agonists are indacterol (Arcapta
Neohaler); vilanterol in conjunction with fluticasone (Breo Ellipta); and
vilanterol in conjunction with the anticholinergic umeclidinium (Anoro Ellipta)
beta andregenic mechanism of action and drug effect
The beta agonists relax and dilate airways by stimulating the beta2-
adrenergic receptors located throughout the lungs.
582
There are three subtypes of these drugs, based on their selectivity for beta2
receptors:
1. Nonselective adrenergic drugs, which stimulate the beta, beta1 (cardiac),
and beta2 (respiratory) receptors. Example: epinephrine. (NOTE: Epinephrine
inhalers were taken off the market in 2012 because they did not comply with
FDA requirements). Epinephrine is available as a prefilled syringe for self-
administration by patients with severe allergic reactions and is called EpiPen
(Figure 37-2).
, 2. Nonselective beta-adrenergic drugs, which stimulate both beta1 and beta2
receptors. Example: metaproterenol.
3. Selective beta2 drugs, which primarily stimulate the beta2 receptors.
Example: albuterol.
These drugs can also be categorized according to their routes of
administration as oral, injectable, or inhaled. The various beta agonist
bronchodilators are listed in Table 37-3. The bronchioles are surrounded by
smooth muscle. When the smooth muscle contracts, the airways are
narrowed and the amount of oxygen and carbon dioxide exchanged is
reduced. The action of beta agonist bronchodilators begins at the specific
receptor stimulated and ends with the relaxation and dilation of the airways.
However, many reactions must take place at the cellular level for
bronchodilation to occur. When a beta2-adrenergic receptor is stimulated by
a beta agonist, adenylate cyclase is activated and produces cyclic adenosine
monophosphate (cAMP). Adenylate cyclase is an enzyme needed to make
cAMP. The increased levels of cAMP cause bronchial smooth muscles to relax,
which results in bronchial dilation and increased airflow into and out of the
lungs.
Nonselective adrenergic agonist drugs such as epinephrine also stimulate
alpha-ad
indications of beta andregenics
The primary therapeutic effect of the beta agonists is the prevention or relief
of bronchospasm related to bronchial asthma, bronchitis, and other
pulmonary diseases. However, they are also used for effects outside the
respiratory system. Because some of these drugs have the ability to
stimulate both beta1- and alpha-adrenergic receptors, they may be used to
treat hypotension and shock (see Chapter 18).