B - 12. Antiinflammatory agents used in bronchial asthma. Antitussive agents and expectorants

Question 1

Leukotriene receptor antagonists; names, mechanism of action

Answer 1

Montelukast

Per oral

Inhibits leukotriene binding in SmM of respiratory tract, causing:

• Decreased SmM contraction
• Decreased mucous production
• Decreased inflammatory responses

Question 2

Leukotriene receptor antagonists; indications, use

Answer 2

Slow onset - used as prophylaxis for exercise or aspirin induced asthma

Given in combo with corticosteroids or B2 agonists as a supportive drug

Question 3

Corticosteroids; mechanism of action

Answer 3

Passes through cell membranes and inhibits inflammatory cytokines

Stops arachodonic acid conversion in mast cells -> decreases production of both leukotrienes and prostaglandins (arachodonic acid -> leukotrienes by 5-LOX)

Downregulates COX2 -> prostaglandin levels decrease (arachodonic acid -> prostaglandin by COX2)

Inhibits proliferation of T-helper2 cells -> IL4 and IL5 decrease

Question 4

IL4 and IL5 importance in inflammatory response

Answer 4

(IL4 -> B-cell -> IgE -> Mast cell activation -> arachadonic acid conversion↑ -> leukotrienes↑ + prostaglandins↑)

(IL5 -> eosinophiles -> cytokines↑ + leukotrienes↑)

Question 5

Leukotriene and prostaglandin actions

Answer 5

Leukotrienes binds to leukotriene receptors on bronchial smooth muscle and causes contraction

Prostaglandin acts similarly

Question 6

Inhaled corticosteroids; names

Answer 6

Fluticasone - longer acting

Budesonide

Question 7

Systemic corticosteroids; names, indications

Answer 7

Prednisolone
Methylprednisolone

Used when inhaled corticosteroid therapy fails

Oral: severe chronic asthma
IV: acute asthma attacks

Question 8

Corticosteroids; side effects

Answer 8

• immune system inhibition - prone to infection
• growth retardation in children
• early bruising
• hyperglycemia
• weight gain
• inhibition of pituitary-adrenal axis - needs gradual downregulation when quitting

inhaled corticosteroids have less severe SE due to being localized to the lungs, but causes oropharyngeal candida

Question 9

Cough suppression easy algorithm

Answer 9

Is the cough dry? -> antitussives

Is the cough wet? -> expectorants and mucolytics

Question 10

Antitussives; names, mechanism of action, side effects

Answer 10

Codeine - opiate - causes drowziness, constipation

Butamirate

Antitussives supress the cough center in medulla oblongata

Do not give to children under one year

Question 11

Expectorants; names, mechanism

Answer 11

Prenoxdiazine

Desensitizes strech receptors in respiratory tract

Question 12

Mucolytics; names, mechanism, side effects

Answer 12

Bromohexidine
Acetylcysteine

Decreases the thickness of mucous

SE: Nausea, vomiting