Respiratory Drugs Actions

Question 1

Beta adrenoreceptor Agonists

Answer 1

Relax smooth muscle, activation of B2 GPCRs, activates adenylyl cyclase = generation of cAMP, vasodilation, inhibits inflammatory mediator release by mast cells (histamine, PGD2). Also increases K+ intake

Question 2

Anticholinergic

Answer 2

M1, M2 and M3 receptors in airways, ACh released from vagus nerve inhibited, bronchodilation and reduced mucus

Question 3

Theophylline

Answer 3

oral or IV (aminophylline). Phosphodiesterase inhibitor = increased cAMP = PKA activation, TNF-a inhibition and leukotriene synthesis inhibition = bronchodilation

Question 4

Corticosteroids

Answer 4

anti-inflammatory and immunosuppressive. Action at nuclear receptors. Inhibit white cell recruitment/ macrophages, reduced vascular permeability = reduce oedema, increase anti-inflam mediators (IL1, IL10), inhibit NF-kB and AP1 synthesis

Question 5

Leukotriene receptor antagonist

Answer 5

reduces airway narrowing and mucous production usually caused by leukotrienes

Question 6

Stabilises mast cells

Answer 6

stabilises mast cells and reduces release of histamine, prevents airway inflammation