NR 566 Week 2 Study Guide 2020– Johns Hopkins University School of Nursing (answers & question 98%)
NR566 Week 2 Study Outline
Chapter 17: Drugs
... [Show More] Affecting the Respiratory System
Bronchodilators:
Beta 2 Receptor Agonists (B2RA): Short and long acting beta agonists
• B2RA widely used in all ages to treat reversible bronchoconstriction caused by reactive airway disease (RAD) or COPD
• Bronchodilators
• Short-acting beta agonists: Albuterol (ProAir, Ventolin, Proventil) , metaproterenol (Alupent), terbutaline (Brethine, Brethaire), bitolterol (Tornalate), pirbuterol (Maxair), and levalbuterol (Xopenex)
• Long-acting beta agonists: arformoterol (Brovana), salmeterol (Serevent), formoterol (Foradil), and indacaterol (Arcapta Neohaler)
• Drug of choice during pregnancy for asthma
Pharmacodynamics
• Act on smooth muscle to reverse bronchospasm, decreases airway resistance and residual volume and increasing VC and airflow
• Stimulate beta 2 adrenergic receptors in the lungs to increase cAMP production which relaxes bronchial smooth muscle and inhibits mediators from hypersensitivity cells (mast cells)
• All beta agonists stimulate beta 1 activity (increased HR, tremor)f
Short Acting Beta Agonists
• Albuterol
o Selective beta2 agonist with minor beta1 activity
o Often first-line drug r/t less ADRs than the other drugs in this class
o Increases HR by stimulating beta 2 receptors in the heart and vascular smooth muscle
• Levalbuterol: (similar to albuterol), where the (S)-isomer from racemic albuterol is removed
• Pirbuterol: selective beta 2 agonist, similar to albuterol
• Terbutaline: similar to albuterol, selective beta 2 with minor beta 1 activity
o Known to inhibit uterine contractions
• Metaproterenol: beta 2 selective with some beta 1 activity, less selective than albuterol or terbutaline
• Bitolterol: hydrolyzed by esterase in the lung to colterol, or terbutylnorepinephrine, selective beta 2
Long Acting Beta Agonists (Salmeterol, formoterol, indacaterol, and aformoterol)
• Salmeterol is more selective for beta2 receptors than albuterol and has minor beta1 activity.
o 12 hour half-life
o Formoterol: 200-fold greater agonist activity at B2 than albuterol and has minor B1 activity
o Aformoterol (R,R)-enantiomer of formoterol, twice as potent as formoterol
o Indacaterol: 24 fold greater B2 activity than B1
o Salmeterol and formoterol exert long-lasting broncho protection against allergen, exercise, histamine, and methacholine caused bronchospasm
Pharmacokinetics
• Contraindications: Cardiac arrhythmias (tachycardia or heart block caused by digitalis intoxication, angina, narrow-angle glaucoma, organic brain damage (epi only), and shock during general anesthesia with halogenated agents
• Monitor closely: HTN, ischemic heart disease, coronary insufficiency, CGH, and Hx of stroke and/or cardiac arrhythmias
• Diabetics: potential drug-induced hyperglycemia, insulin dose may need increased
• Hyperthyroidism: ADRs are more likely to occur with use of bronchodilators
• Digoxin: require close monitoring, albuterol increases the volume of distribution of dig and can cause decreased dig blood levels
• Pheochromocytoma: avoid, severe HTN may occur
• Older adults: Lower doses r/t increased sympathomimetic sensitivity [Show Less]