Airway pharmacology Flashcards
What can drugs that treat asthma do?
→ Reverse smooth muscle contraction
→ Reduce mucus secretion
→ Reduce allergic inflammation of airways
→ Reduce sensitivity to irritating stimuli
What can’t drugs that treat asthma do?
→ Resolve causes of inflammation
→ Reverse airway remodelling
→ Repair damage to tissues
What are the types of beta 2 adrenergic receptors agonists?
→ SABA (short acting)
→ LABA (long acing)
→ Ultra LABA (ultra long acting)
What are the other 2 types of drugs used to treat smooth muscle contraction?
→ Long acting muscarinic receptor antagonists
→ Phosphodiesterase inhibitors
What is the mechanism of smooth muscle contraction?
→ Contractile mediators bind to Gq receptors
→ Phospholipase C is cleaved
→ DAG and IP3 are produced
→ IP3 binds to SR and causes calcium release
→ Contraction occurs
How does salbutamol prevent smooth muscle contraction?
→Salbutamol binds to a Gs beta 2 receptor → Gs is stimulated → cAMP increases → PKA is activated → PKA results in a decrease in Ca2+ → Smooth muscle relaxes
How do corticosteroids work?
→ diffuses through the membrane and binds to a glucocorticoid receptor
→ Drug receptor complex moves to the nucleus
→ Binds to DNA and affects transcription
→ translates gene into protein
How do corticosteroids affect genes?
→ They increase anti inflammatory genes
→ decrease pro inflammatory genes
What are some considerations to take into account when using drugs?
→ Increased quality of life
→ Less symptoms
→ Increased life expectancy
→ Disease resolution or decrease in severity
What are adverse effects drugs can have?
→ Decreased quality of life
→ Increased risk in developing other diseases
→ cost
Why are drugs for asthma given as metered dose inhalers?
→ Helps the drug target the lungs and minimizes its effect on other tissues
What other receptors can salbutamol act on and where, and what side effects can occur?
→ Beta 1 in heart
tachycardia, palpitations
→ Beta 2 in skeletal muscle
tremors, muscle growth
What are the side effects of long term corticosteroid use?
→ Growth retardation → Skin ulcers → Candidiasis → Osteoporosis → Hypercortisolism → Depression
How is asthma pharmacotherapy administered?
→ In a stepwise manner
→ If the disease gets worse you move them up a step to a stronger drug
→ If their condition is stable and seems to be improving you move them down a step
What is COPD therapy like?
→ Progressive