(4) Smooth Muscle: Allergy & Pulm (2.1-2.2)

Question 1

Where is most Histamine found?

Answer 1

Mast cells

Question 2

What type of G-protein is H₁ receptor?

Answer 2

G_q

Question 3

What type of G-protein is H₂ receptor?

Answer 3

G_s

Question 4

Name 6 effects of H₁ receptor stimulation

Answer 4

(1) ↑ Nasal/Bronchial mucus
(2) ↑ Vascular permeability
(3) Bronchoconstriction
(4) ↑ Arousal
(5) Pain
(6) Pruritus
* (CNS Effects: Regulates sleep, arousal, and functions as a neurotransmitter)*

Question 5

Which Histamine receptor mediates gastric acid secretion?

Answer 5

H₂

Question 6

Name the first-generation H₁ receptor blockers

Answer 6

(1) Diphenhydramine
(2) Dimenhydrinate
(3) Chlorpheniramine
(4) “-zine”

Question 7

Indications (5) : H₁ receptor blockers

Answer 7

(1) Type I Allergic Reactions
(2) Motion sickness
(3) Insomnia
(4) Extrapyramidal side effects of antipsychotics
(5) Anorexia
* (Note: Only first-generation H1 blockers treat motion sickness)*

Question 8

What other receptors do first-generation H₁ blockers antagonize (not H₁)?

Answer 8

(1) CNS/PNS Muscarinic receptors
(2) CNS 5-HT receptors
(3) α₁ receptors

Question 9

Why do H₁-blockers cause cognitive impairment in the elderly?

Answer 9

(1) Central antihistamine effects
(2) Central antimuscarinic effects

Question 10

What are the second-generation H₁ blockers?

Answer 10

(1) Fexofenadine
(2) Cetirizine
(3) Loratidine

Question 11

How are second-generation H₁ blockers different than the first-generation blockers?

Answer 11

(1) Do not cross BBB
(2) ↑ H₁ specificity
* (↑ Specificity ⇒ ↓ Affinity for muscarinic receptor, 5-HT receptors, and adrenergic receptors)*

Question 12

Which class of sympathomimetics are used to treat bronchoconstriction in asthma?

Answer 12

β2 agonists

(“-rol” drugs)

Question 13

What β2 does not end in “-erol” and is used to treat asthma?

Answer 13

Terbutaline

Question 14

Treatment (8) : Persistent asthma (not β2 agonist)

Answer 14

(1) Inhaled corticosteroids
(2) Direct lipoxygenase inhibitors
(3) Methylxanthines
(4) Omalizumab
(5) Cromolyn Sulfate
(6) LTD4-receptor antagonists
(7) Ipratropium
(8) Epinephrine

Question 15

How do corticosteroids help with asthma?

Answer 15

(1) ↓ Inflammation
(2) ↓ Leukocyte infiltration
* (Importantly, they also upregulate β2 receptors)*

Question 16

Adverse Effect: Inhaled corticosteroids

Answer 16

Oral candidiasis

(Inhaled steroids are not absorbed systemically ∴ they avoid systemic effects)

Question 17

Which leukotriene is a potent chemoattractant for neutrophils?

Answer 17

LTB₄

(IL-8 also a potent neutrophil chemoattractant. IL-8 looks like IL-B)

Question 18

Which leukotrienes are potent bronchoconstrictors?

Answer 18

LTC₄, D₄, E₄

(Also ↑ Airway vascular permeability and mucus production)

Question 19

What receptor mediates the most potent bronchoconstricting effects of leukotrienes?

Answer 19

CysLT1

Question 20

Suffix: LTD4-receptor antagonists

Answer 20

“-kast”

Question 21

ROA: LTD4-receptor antagonists

Answer 21

Oral

Question 22

What drug is a direct lipoxygenase inhibitor?

Answer 22

Zileuton

Question 23

Which asthma drug requires monitoring for hepatotoxicity?

Answer 23

Zileuton

Question 24

What drug can cause a leukotriene-induced asthma attack?

Answer 24

Aspirin

(NSAIDs in general)

Question 25

Name two long acting β2 agonists

Answer 25

(1) Salmeterol
(2) Formoterol
* (Salute ∝ Salmeterol)*
* (Formation ∝ Formoterol)*

Question 26

MOA: Methylxanthines

Answer 26

(1) Non-selective PDE inhibitor
(2) Adenosine receptor antagonist
* (∴ ↑ cAMP)*

Question 27

ROA: Theophylline

Answer 27

Oral

Question 28

Adverse Effects (2) : Methylxanthines

Answer 28

(1) CNS effects incl. tremor
(2) Tachycardia

Question 29

Which asthma drug is metabolized by the CYP-450 system?

Answer 29

Methylxanthines

Question 30

What monoclonal antibody is used to treat allergic asthma?

Answer 30

Omalizumab

Question 31

MOA: Omalizumab

Answer 31

Binds Fc portion of IgE

Question 32

MOA: Cromolyn Sulfate

Answer 32

Inhibits mast cell degranulation

(And ∴ histamine release)

Question 33

Treatment (4) : Acute severe asthma attack

Answer 33

(1) IV corticosteroid
(2) β2 agonist

(3) Ipratropium
(4) Epinephrine