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Flashcards in Asthma & COPD Deck (43)
1

drugs useful for treating asthma

1. B2 –agonists (albuterol, terbutaline, pirbuterol, levalbuterol, metaproterenol, bitolterol, formoterol, salmeterol)
2. Corticosteroids (beclomethasone, triamcinolone, flunisolide, fluticasone, budesonide, mometasone)
3. Cromolyn and Nedocromil
4. Muscarinic antagonists: ipratropium and tiotropium
5. Theophylline
6. Leukotriene antagonists (zafirlukast, montelukast, zileuton)
7. Omalizumab

2

B2 agonists drugs

short-acting (SABA): albuterol, levalbuterol, terbutaline, pirbuterol, bitolterol, metaproterenol
long-acting (LABA): salmeterol, formoterol

3

B2 agonists use

SABAs are the drugs of choice for mild asthma; these drugs have no anti-inflammatory effects and should never be used as the sole therapy for patients with chronic asthma; they are used for symptomatic relief from asthma but long-term 2 agonist use is controversial

4

B2 agonists moa

directly relax bronchial smooth muscle by acting on 2 receptors in the lungs; stimulation of this receptor activates adenylyl cyclase and increases cAMP, which in turn activates PKA which phosphorylates the MLCK and causes muscle relaxation; stabilizes mast cell membranes

5

B2 agonists kinetics

the short-acting agents have a rapid onset of action (5-15 min. inhaled, 15-30 min. oral) and provide relief for 4-6 hours; LABAs have a slower onset of action (about 1 hour) but provides relief for at least 12 hours; LABAs are not used for acute asthmatic attacks; given usually as metered-dose inhalers (MDI) and also by nebulizer; these drugs are not catecholamines so are not destroyed by catechol-O-methyl-transferase (COMT)

6

B2 agonists adverse

as selective 2 –agonists given in the form of inhalers, these drugs have few adverse effects; excessive doses can cause skeletal muscle tremor and cardiac stimulation; unnecessary use has been associated with the increase in asthma mortality

7

The use of orally administered 2 –agonists ...

has not gained wide acceptance due to the risk of systemic side effects such as muscle cramps, cardiac tachyarrhythmias, and metabolic disturbances; there are two situations where oral 2 –agonists are used frequently: in young children (<5 years old) who cannot manipulate a metered dose inhaler oral therapy with albuterol or metaproterenol syrups are well tolerated and effective, and second, oral therapy is effective in patients who experience irritation or enhanced cough or bronchospasms when using the inhaler

8

CORTICOSTEROIDSs drug

Inhaled: beclomethasone, triamcinolone, flunisolide, fluticasone, budesonide, mometasone
Systemic: methylprednisolone, prednisolone, prednisone

9

CORTICOSTEROIDS use

moderate to severe asthma; asthmatic patients who require inhaled 2 -agonists four or more times weekly are reviewed as candidates for inhaled corticosteroids; severe asthmatics may require systemic glucocorticoids for a short term

10

CORTICOSTEROIDS moa

act on cytoplasmic glucocorticoid receptors and stimulate protein synthesis (4-12 hours before clinical response is seen); are anti-inflammatory; to be effective in controlling inflammation, these drugs must be taken continuously; these steroids have no direct effect on the airway smooth muscle; three main benefits from corticosteroids are 1) inhibition of inflammation at all levels, 2) reducing mucous production and hypersecretion, 3) increasing 2 receptor levels

11

CORTICOSTEROIDS kinetics

a. the development of inhaled steroids have greatly reduced the need for systemic corticosteroid treatment;a large fraction (80-90%) of the inhaled dose is deposited in the mouth and pharynx, or is swallowed, and these steroids are absorbed from the gut and enter the systemic circulation through the liver
b. most inhaled corticosteroids undergo extensive first- pass metabolism so only a small portion of the drug reaches the systemic circulation; the 10-20% that is
not swallowed is deposited in the lungs

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systemic corticosteroids

used in patients with severe exacerbation of asthma (status asthmaticus) and are given IV as methylprednisolone (Solu-Medrol) or orally; once the patient has improved, the dose of drug is gradually decreased leading to discontinuance in 1-2 weeks

13

spacer

a spacer is a large volume chamber that is attached to the metered-dose inhaler and is used to decrease the deposition of drug in the mouth; the chamber reduces the velocity of the injected aerosol and also serves as a type of filter to allow mainly small drug particles to be deposited in the mouth; the small particles are more likely to reach the target airway tissue

rinsing the mouth after inhalation can also decrease systemic absorption and the possibility of oropharyngeal candidiasis (thrush)

14

CORTICOSTEROIDS adverse

in the inhaled form, thrush may be a problem; when given orally or parenterally a number of adverse effects can be observed

15

Cromolyn and Nedocromil use

Are effective as prophylactic antiinflammatory agents, but are not useful in managing an acute asthma attack because they are not direct bronchodilators
Therapeutic use: mild to moderate asthma; pretreatment with either drug prevents exercise-induced and allergen-induced asthma; especially useful in children due to effectiveness and few side effects (better than corticosteroids)

16

Cromolyn and Nedocromil moa

these drugs inhibit pulmonary mast cell degranulation in response to a variety of stimuli which, in turn, prevents the release of histamine and other granular contents

17

Cromolyn and Nedocromil kinetics & adverse

Pharmacokinetics: both drugs are given by inhalation (MDI)
Adverse effects: usually infrequent and minor; rare instances of anaphylaxis, laryngeal edema, headache, rash, and nausea have been reported (cromolyn is touted as the “least toxic drug” used to treat asthma; adverse effects in 0.01% of patients)

18

Muscarinic Antagonists drugs

Ipratropium (SAMA) and tiotropium (LAMA) are antimuscarinics

19

Muscarinic Antagonists use

variable among asthma patients and is often assessed on an individual basis; differences in parasympathetic tone probably account for the differences; useful in patients unable to take 2 –agonists; not used for acute asthma attacks

20

Muscarinic Antagonists moa

blocks muscarinic receptors (M1, M2, M3) thereby reducing parasympathetic flow and blocking contraction of bronchial smooth muscle; tiotropium differs by blocking only M1, M3 receptors

21

Muscarinic Antagonists kinetics & adverse

Pharmacokinetics: given as an inhaler; slow onset; is sometimes used in combination with a 2 –agonist (albuterol) in a drug called Combivent or Duoneb for COPD; usually given on a regular basis 4 times a day
Adverse effects: minimal since very little systemic absorption occurs

22

Theophylline

Previously was the primary drug used in asthma therapy but has now been largely replaced by 2 –agonists and corticosteroids; is part of a family of compounds known as the xanthines of which caffeine is a member

23

Theophylline use

limited use in asthma patients; not recommended for acute attacks; given chronically, may reduce asthma symptoms and reduce the need for inhaled 2-agonists and/or inhaled corticosteroids; sustained-release form is effective for nocturnal asthma

24

Theophylline moa

inhibition of phosphodiesterase III (PDE III) found in airway smooth muscle, and PDE IV found in inflammatory cells which results in increased cAMP; the net effect is to relax bronchial smooth muscle and to prevent release of cytokines from inflammatory cells; blocks adenosine receptors

25

Theophylline kinetics & adverse

Pharmacokinetics: a variety of factors influence the pharmacokinetics of theophylline including food, smoking, age, and other drugs; given orally, rectally, or parenterally
Adverse effects: theophylline and caffeine have a number of physiological effects on the CNS and the cardiovascular system, and have diuretic actions; GI effects are most prominent

26

Leukotriene antagonists (zafirlukast, montelukast, zileuton) moa

act by blocking the leukotriene receptor – cys-LT1 (zafirlukast, montelukast) or by blocking the 5-lipoxygenase enzyme (zileuton) and inhibiting the formation of leukotrienes; leukotrienes, like histamine, are local inflammatory mediators and bronchoconstrictors

27

Leukotriene antagonists (zafirlukast, montelukast, zileuton) use

alternatives to inhaled steroids in mild asthmatics or as adjuncts to inhaled steroids in severe asthmatics (montelukast used in kids age 1 and over and adults; zafirlukast children age 5 and older; zileuton age 12 and over)

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Leukotriene antagonists (zafirlukast, montelukast, zileuton) kinetics & adverse

Pharmacokinetics: given orally (may improve compliance)
Adverse effects: headache is the main adverse effect (13% of patients)

29

Omalizumab

is a monoclonal antibody that inhibits the immune response (anti IgE) in moderate to severe allergen-induced asthma; the product appears safe and effective in patients
12 and older; it is given as an injection under the skin very two to four weeks; anaphylaxis and a slight increased risk for cancer have been reported as side effects

30

Choice of drugs for exercise-induced asthma

inhaled 2 agonists have the highest efficacy and are the agents of choice for prophylactic therapy
cromolyn is preferred is patients intolerant to inhaled 2 agonists

31

Use of drugs exercise-induced asthma

for typical periods of exercise (<3 hrs), pretreatment with albuterol or terbutaline usually provides excellent protection
for prolonged periods of exercise, long-acting inhaled 2 agonists such as salmeterol provide 12 hours of protection
in moderate to severe asthmatics, long-term inhaled anti-inflammatory therapy (corticosteroids) is helpful in reducing the response to most asthma triggers including exercise
in patients who only experience exercise-induced asthma, use of an inhaled 2 agonist a few minutes before exercise is usually sufficient therapy

32

Choice of drugs for nocturnal asthma

short-acting inhaled 2 agonists are not long-acting enough to prevent early morning symptoms, therefore, salmeterol is the optimal choice for nocturnal asthma

33

do not use ...

NSAIDS and beta blockers in asthmatics
5-20% of asthma patients are sensitive to aspirin; rhinorrhea,
mild wheezing, or severe shortness of breath

Most clinicians prefer acetaminophen as an analgesic and
antipyretic in asthmatics

34

DRUG-INDUCED ASTHMA

If a patient has to take NSAIDS such as aspirin for post myocardial infarction or other NSAIDS for arthritis, you may choose to desensitize the patient
Non-specific beta blockers should be avoided in asthmatics and 1 selective drugs used with caution. Even ophthalmic timolol has caused fatal asthma and should be avoided in patients with asthma.

35

COPD meds

Nicotine
Bupropion
Varenicline

36

Bupropion

is a heterocyclic antidepressant; its MOA for smoking cessation is unknown; FDA warning about neuropsychiatric symptoms including suicide

37

Varenicline

N partial agonist (prevents nicotine binding thereby blocking the release of DA in the mesolimbic tract; blocks the reinforcing effect of DA); taken orally once a day; nausea in 30% of patients on higher doses; suicide

38

COPD bronchodilators

Short-acting = SABA or SAMA
Long-acting = LABA or LAMA; theophylline is rarely considered

39

Corticosteroids

role in treating COPD is much less than the role in asthma
may be most beneficial for patients with a history of asthma
try a trial of 20-30 mg oral prednisone for 2-3 weeks and check for responsiveness; if successful, change to inhaled steroids

40

ACUTE AND CHRONIC RHINITIS drugs

Histamine H1 receptor antagonists:
these agents are the first-line treatment for both perennial and seasonal allergic rhinitis and conjunctivitis; reversible H1 receptor blockers

Decongestants: H1 antagonists do not relieve the nasal congestion associated with rhinitis and are often used in combination with decongestants (pseudoephedrine, phenylephrine, naphazoline, oxymetazoline); all of the decongestants are sympathomimetics that stimulate 1 receptors

Corticosteroids: intranasal corticosteroids are useful in treating rhinitis

Cromolyn: intranasal cromolyn is also useful for rhinitis

41

Dextromethorphan

is the d isomer of the codeine analog levorphanol, but unlike the l isomer it has no analgesic or addictive properties and does not act through opioid receptors
mechanism of action: acts on the cough center in the medulla to raise the threshold for coughing
therapeutic use: available OTC for cough; equally as effective as codeine
pharmacokinetics: oral
adverse effects: some GI effects but fewer effects compared to codeine; extremely high doses may cause CNS depression

42

other cough medicine

Codeine and hydrocodone
Benzonatate (Tessalon)
mechanism of action: anesthetizes stretch receptors in respiratory passages
given orally

43

EXPECTORANTS

Guaifenesin (Humibid, many combination products): increases
the output of respiratory tract fluid by reducing adhesiveness
and surface tension