LONG-ACTING BETA AGONISTS
Arformoterol (Brovana), salmeterol (Serevent), formoterol (Foradil), indacaterol (Arcapta
Neohaler)
Associated risk for intubation and death.
Should not be used alone- used in combination with an asthma controller medication such as
inhaled corticosteroid (for peds/adolescents, single preparation both LABA and corticosteroid-
to enhance compliance)- see BLACK BOX WARNING
Should only be used long-term in patients whose asthma cannot be adequately controlled on
asthma controller medication.
Pharmacodynamics
act on the smooth muscle of the bronchial tree to reverse bronchospasm, thereby decreasing
airway resistance and residual volume and increasing vital capacity and airflow.
Beta agonists stimulate beta-2 adrenergic receptors in the lungs to increase production of cyclic
adenosine monophosphate (cAMP) by activation of adenyl cyclase, the enzyme that catalyzes
the conversion of ATP to cAMP.
Increased cAMP concentrations relax bronchial smooth muscle and inhibit release of mediators
of immediate hypersensitivity from cells, especially from the mast cells.
ALBUTEROL- selective beta-2 agonist with minor beta-1 activity.
o a.k.a. “Salbutamol”
o can increased HR by stimulating beta-2 receptors in the heart, and beta-2 receptors in
vascular smooth muscles (vasodilation -> decreased DBP -> increased HR)
o has fewer cardiac and CNS effects than other
o drug of choice of FIRST LINE THERAPY
o similar structure: levalbuterol, pirbuterol
TERBUTALINE- selective beta-2 agonist with minor beta-1 activity (similar to albuterol)
o Also known to inhibit uterine contractions
o To prevent contractions related to preterm labor (off label use).
SALMETAROL and FORMOTEROL- exert long-lasting bronchoprotection effects against allergen-,
exercise-, histamine-, and methacholine-cause bronchospasm.
Pharmacotherapeutics
CONTRAINDICATIONS:
o cardiac arrhythmias associated with tachycardia or heart block caused by digitalis
intoxication, angina, narrow-angle glaucoma, organic brain damage, shock during
general anesthesia
o pheochromocytoma (diagnosed or suspected)- may cause severe HTN
, MONITOR CLOSELY FOR ADVERSE EFFECTS (cardiovascular system): patients with HTN, ischemic
heart disease, coronary insufficiency, CHF, hx of stroke and/or cardiac arrhythmias
BLACK BOX WARNING: salmeterol and formoterol
o Respiratory-related asthma and asthma-related deaths and risk is higher for African
Americans.
Patients on digoxin: monitor closely with use of albuterol- increased volume of distribution of
digoxin and can cause up to a 30% decrease in blood digoxin levels.
All are PREGNANCY CATEGORY C, except -> Terbutaline (pregnancy category B)
Clinical use
Bronchospasm- asthma, bronchitis, COPD
Exercise-induced bronchospasm
Drug interactions
Digitalis glycosides- caution and careful monitoring of patient’s EKG (increased risk of cardiac
arrhythmia)
Beta-adrenergic blockers- mutual inhibition of therapeutic effects
TCA and MAOI- may potentiate effects on vascular system when taken with albuterol,
metaproterenol, or terbutaline.
Beta agonists- coadministration may lead to hypokalemia or EKG changes.
Adverse drug reactions
Drug-induced hyperglycemia for pts with DM- insulin may need to be increased.
Overuse may lead to: seizures, hypokalemia, anginal pain, HTN
Increased HR
Tremors
GI upset- take with food for oral forms
Tachycardia, chest pain, muscle tremors, dizziness, flushing- inform healthcare provider.
XANTHINE DERIVATIVES
Methylxanthines- have declined in importance in the treatment of asthma
o Caffeine
o Aminophylline
Pharmacodynamics
Work directly by unknown mechanism believed to be mediated by selective inhibition of specific
phosphodiesterases (PDEs) -> increase in cAMP -> bronchial smooth muscle and pulmonary
vessel relaxation
Theophylline and Caffeine
o powerful CNS stimulants
o increase gastric acid secretion – may cause n/v
o stimulate skeletal muscles- tremors
o increased renal blood flow -> increased GFR -> increased Urine output (diuresis)
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