W6 Pharmaceutical Chem Of Res System

Question 1

What are the class of drugs for respiratory system?

Answer 1

•Beta-2 Agonists (SABA + LABA)
•Leukotriene Receptor Antagonists
•Methylxanthines
•Muscarinic Agents (SAMA + LAMA)
•Corticosteroids
•Mucolytic Agents

Question 2

What is a pharmacophore?

Answer 2

The section of the drug structure that is responsible for its biological activity (often the part that binds to a receptor)

*Pharmacophore modelling is often used to establish the essential criteria for the drug
•Docking methods are then often employed to screen a library of molecules to determine which theoretically could be active

Question 3

SABA
What is their function?
Onset?
How long do their effects last?

Answer 3

Short-Acting Beta-2 Agonists (SABAs)

*Act directly on beta-2 receptors in the lungs
*Causes smooth muscle relaxation and dilation of the airways
*Rapid onset (≈ 15 minutes)
*Effects last for up to 4 hours

Question 4

Long-Acting Beta-2 Agonists (LABAs)

Answer 4

•Act directly on beta-2 receptors
•Causes smooth muscle relaxation and dilation of the airways
•Rapid onset is also possible
•Effects can last for up to 12 hours

Question 5

Leukotriene Receptor Antagonists (LTRAs)

Answer 5

•Antagonist vs agonist
•Cysteinyl leukotrienes: bronchoconstriction, smooth muscle hypersensitivity, inflammation, mucus formation
•LTRAs reach maximal plasma concentration within 3 hours
•Half-life can be up to 10 hours
•Bronchodilation and anti-inflammatory effects

LTD4 – Cysteinyl leukotriene

Activity: Identify the important elements that must be conserved and whi

Question 6

Methylxanthines:
What is an example?
moA?

Answer 6

*Theophylline
*Bronchodilator
*Reverse resistance to corticosteroids
*Mechanisms of action include PDE₄ inhibition & HDAC (histone deacetylase) activation
*Also active in CNS, CVS, and GI

Question 7

What are Short-Acting Muscarinic Antagonists?
(SAMAs)
What is an example?
What is the onset time?
How long do the effects last?

Answer 7

• Ipratropium Bromide
• Bronchodilator
• Onset around 30 mins
• Effects last 3-5 hours
• Quaternary nitrogen compound
• Does not discriminate between
  muscarinic receptor subtypes

Question 8

Long-Acting Muscarinic Antagonists
(LAMAs)
examples?

Answer 8

• A few common drugs
• Bronchodilator (blocks
  bronchoconstriction)
• Onset varies – can be rapid
• Effects last 12-24 hours (depending on
  drug)
• Also quaternary nitrogen compounds
• Greater selectivity for M₃ receptor

Mepenzolate, Tiotropium, Glycopyrronium, Acidinium

Question 9

Structure of a Corticosteroid:
-how many rings?
-examples?
- moA?

Answer 9

• 4 ring system
• Beclometasone, budesonide, ciclesonide,
  fluticasone, mometasone, prednisolone
• Anti-inflammatory effects
• Multiple mechanisms of action (inhibit
  PGE₂ and PGI₂, inhibit leukotrienes, up-
  regulate β₂ receptors) – Dr Healy

Question 10

What are some examples of mucolytic agents?

Answer 10

N-acetylcysteine
Erdosteine
Carbocysteine