Lecture 53 - Drugs for Lung Disease; Anti-tussives; Anti-histamines

Question 1

what drug classes are used in the setting of Asthma and COPD acute exacerbations ?

Answer 1

○ SABA
○ Short-acting anticholinergics
○ Systemic corticosteroids

Question 2

What drugs are used as maintenance therapy for asthma?

Answer 2

§ ICS
			§ LABA (in conjunction with ICS)
			§ Cromolyn and Nedocromil
			§ Leukotriene modifiers
			§ Omalizumab

Question 3

What drugs are used as maintenance therapy for COPD?

Answer 3

§ Long-acting anticholinergics

§ LABA

Question 4

Bronchodilators for COPD and Asthma?

Answer 4

Beta2 Agonists

Anticholinergics

Methylxanthines

Question 5

Mechanism of Beta 2 agonists?

Answer 5

Stimulates beta2 receptors causing an increase in cAMP which causes smooth muscle relaxation (bronchodilation), mast cell stabilization and skeletal muscle stimulation

Question 6

Side effects of SABA and LABA

Answer 6

Tachycardia/palpitations
Transient decrease in serum potassium levels
Tremors
Lactic acidosis

LABA – same as above, but also carry increased risk of asthma realted death when not used with corticosteroids

Question 7

Anticholinergics

• • what are some drugs?
• • mechanism

Answer 7

Ipratropium bromide (short-acting)
Tiotropium (long-acting)

Inhibit muscarinic receptors (M1 and M3) in bronchial smooth muscle which blocks Ach binding and increases cGMP which leads to bronchodilation

Question 8

Anticholinergics – side effects?

Answer 8

Blurred vision
Dry mouth
Nausea
Urinary retention
CNS effects
Tachycardia
Increased CV events

Question 9

Methylxanthines –

• • what drug is in this class?
• • mechanism ?

Answer 9

Theophylline

Non-selective inhibition of phosphodiesterase which increases cAMP and cGMP  bronchodilation

Inflammatory cell regulation

Competitive antagonist of adenosine and stimulates endogenous catecholamine release (beta2  bronchodilation)

Question 10

Why is Theophylline rarely used clinically ?

what are some side effects?

Answer 10

narrow therapeutic window

Nausea and vomiting
Gastric upset
Tachyarrhythmia
Jitteriness
Insomnia
Headache
seizures

Question 11

Corticosteroids —
indications for use

– what are they drugs? which has the lowest potency, which has the highest?

Answer 11

Acute exacerbation of asthma and COPD
maintenance therapy to prevent bronchospasm
allergic rhinitis

Hydrocortisone (low potency)
Prednisone (medium potency)
Methylprednisone (medium potency)
Dexamathasone (high potency)

Question 12

Side effects of corticosteroids

– what specific infection can occur with inhaled corticosteroids?

Answer 12

Acute setting: Hypergylcemia, HTN,

Long term: HPA suppression, growth retardation, muscle myopathy, osteoporosis, impaired wound healing

Oral steroids – candidiasis

Question 13

Mast Cell Stabilizing Drugs
- 
what are they? 
mechansim? 
indications?

Answer 13

Cromolyn
Nedocromil

Inhibits mast cell degranulation

Long term treatment for prevention of symptoms of asthma

Question 14

Side effects of mast cell stabilizing drugs?

Answer 14

cromolyn: Cough and wheezing

Nedocromil – Cough and wheezing + dyguesia

Question 15

Leukotriene Modifiers

two types? (different mechanisms)
what are the drugs?

Answer 15

Leukotriene receptor antagonists — • Zafirlukast (Accolate); Montelukast (Singular; taken once a day)

5-lipoxygenase inhibitor that prevents conversion from arachindonic acid to leukotrienes
Zileuton

Question 16

Indications for the use of leukotrinee modifiers?

side effects for each class?

why is Zileuton not really used ?

Answer 16

◊ Long term control and prevention in patients with asthma
Allergic rhinitis

Luekotriene Antagonists: Headache
Nausea
Abdominal pain

Zileuton –
Liver toxicity
Hyperbilirubinemia

Question 17

Antihistamines
mechanism?
whats the difference between first and second generation?

Answer 17

Competitive antagonist to H1-receptors that prevent histamine binding and action which will allow for bronchodilation (and effects on vascular smooth muscle and endothelial cells as well as nerves)

First generation: lipophilic and non-selective, anticholinergic effects

Same mechanism as above
Second generation: specific to peripheral histamine receptor

Question 18

what are some first generation anti-histamines drugs?

Indications?

side effects?

Answer 18

Diphenhydramine HCl
Hydroxyzine
Promethazine

Allergic reactions
Allergic rhinitis
Anti-emetic

Anti-cholinergic effects: dry mouth, drowsiness, urinary retention, blurry vision
GI effects: nausea, abdominal pain
CNS effects: sedation, drowsiness

Question 19

what are some second generation anti-histamines ?

Indications?

side effects?

Answer 19

Cetirizine/Levocetirizine
Loratidine
Fexofenadine

same indications

Low to none sedative, GI or anti-cholinergic effects

Question 20

Antitussives:
- mechanism of the following drugs:

Opioids: (Codeine, Hydrocodone, Hydromorphone)

Dextromethorphan

Answer 20

Acts centrally on respiratory center in medulla and nucleus tractus solitaris to increase cough threshold

Question 21

Side effects of opioids

side effect of Dextromethrophan

Answer 21

Nausea and vomiting
Sedation
Constipation

CNS effects at high doses: confusion, excitation, nervousness, irritability
Respiratory depression may occur with very high doses

Question 22

Antitussive: Benzoate

mechanism:

side effects?

Answer 22

Anesthetic effect on stretch receptors of the vagal afferent fibers in the bronchi, alveoli and pleura —> blocking of cough reflex

May also suppress transmission of signal of cough reflex at medulla

Nausea
Mucosal numbness (if you chew it)

Question 23

Expectorant: Guaifenesin

mechanism –

indications –

Symptoms –

Answer 23

Loosens and thins lower respiratory secretions

Symptomatic relief of ineffective productive coughs

Nausea and vomiting
Dizziness
Diarrhea