L 25 Asthma

Question 1

Describe bronchiole innervation

Answer 1

Bronchioles are innervated by cholinergic nerves which cause constriction and Beta-2 nerves which cause dilation

Question 2

What are the mediators of branchial asthma?

Answer 2

Acetylcholine Neurokinin A Substance P Histamine Leukotrienes Platelet activating factor PG D2, F2alpha

Question 3

Explain the overall picture of the agents that affect bronchodilation

Answer 3

Question 4

What is COPD?

Answer 4

Chronic bronchitis Involves inflammation, and irritation Cilia are immobilized and particles are not kept out Goblet cells make more mucous Susceptible to infection, airways narrowed, chronic cough

Question 5

What is emphysema?

Answer 5

Walls of alveoli breakdown leaving fewer alveoli for respiration Fibrosis and loss of elasticity make breathing difficult

Question 6

What are the general groups of drugs used to treat asthma?

Answer 6

Beta-agonists: fast, but short-acting and first-line treatment Muscarinic antagonists: DOC for COPD Anti-inflammatory: first line for chronic asthma and used to prevent beta receptor down-regulation, and decrease mucous secretion Leukotriene inhibitors: prevent constriction, eosinophil migration, edema

Question 7

Describe agents and function of the short-acting, rescue inhaler beta 2 agonists

Answer 7

Beta2 agonists increase cAMP leading to relaxation of airway smooth muscle, also inhibit histamine release from mast cells, generally inhaled but oral form is available Albuterol, Levalbuterol, Pirbuterol, Terbutaline, Bitolterol Effects last 4-6 hours, onset is immediate, used to stop an attack in progress

Question 8

Salmeterol

Answer 8

Long-acting beta2 agonist Used for prevention and prophylaxis Effects take 20-30 mins Always combined with a steroid like Advair

Question 9

Why are long-acting beta2 agonists for asthma also given steroids?

Answer 9

Long-acting beta2 agonists cause down-regulation of the receptors, steroids like Advair help to prevent this and sensitize the receptors

Question 10

Formoteral

Answer 10

Similar to Salmeterol

Question 11

Side effects of beta2 agonists

Answer 11

Tachycardia, nervousness, dizziness, tremor

Question 12

Ipratropium (Atrovent)

Answer 12

Muscarinic antagonist Inhaled, poorly soluble, not absorbed Used in COPD Combined with albuterol

Question 13

Theophylline

Answer 13

Increases cAMP-(phosphodiesterase inhibitor) Blocks adenosine receptors Relaxes smooth muscle, stimulate CNS and heart Used for COPD not otherwise controlled by Beta agonists or muscarinic antagonists Low therapeutic window Side effects like drinking a cup of coffee–these are why it is rarely used

Question 14

Corticosteroids and asthma

Answer 14

Used for long-term treatment of asthma Decrease: inflammation, beta receptor down regulation, bronchiole hypersensitivity, mucous secretion, mediators of inflammation Oral or inhaled Thrush is common side effect as well as osteoporosis

Question 15

Roflumilast (Daliresp)

Answer 15

Inhibits PDE4 Increases cAMP Only used for severe COPD not responding to other drugs Nausea main side effect

Question 16

Omalizumab (Xolair)

Answer 16

Monoclonal antibody to IgE preventing it binding to cells associated with allergic response Used for moderate to severe allergic asthma Side effects: rash, reduction in platelets, injection site reactions

Question 17

Leukotriene inhibitors

Answer 17

Zileuton (Zyflo): inhibits 5-lipoxygenase Zafirlukast (Accolate) Montelukast (Singulair) Pranlukast (Ultair) Last three are leukotriene receptor antagonists Have no effect on attack in progress May allow decreased steroid dose Zileuton may decrease aspirin sensitive asthma Cause URI’s, sore throat, headache, abd pain, sleepiness

Question 18

Cromolyn sodium, Nedcromil

Answer 18

Inhibits release of histamine to treat asthma Mainly used in kids Taken 4x per day chronically For prevention Available for nasal use OTC