Flashcards in Respiratory Examination - Asthma, COPD + Corticosteroids Deck (33)
Name 5 drugs commonly used in the treatment of lung conditions
Muscarinic Receptor Antagonist
Leukotriene Receptor Antagonists
Loop diuretics (Pulmonary oedema)
Name some major B2 agonists
Short acting - Salbutamol
Long acting - Salmeterol
Mechanism of action of B2 agonists
Act on B2 receptors found on bronchial smooth muscle. The receptors are coupled to Gs Proteins, which cause an increase in cAMP and consequent decrease in intracellular [Ca2+]. This reduces the binding of Ca2+ by light myosin, causing smooth muscle dilation.
- Additionally, the decrease in intracellular Ca2+ will also and increase Ca2+ activated K+ currents, thus hyperpolarising muscle cells further and augmenting bronchodilation.
Give two ADRs of b2 agonists
Skeletal muscle tremor
Can act on cardiac B1 receptors to induce tachycardia and cardiac dysrhythmia
Give one negative drug-drug interaction of B2 agonists
Propanolol (beta blocker) reduces effects
Name a muscarinic receptor antagonist
Mechanism of action of muscarinic receptor antagonists?
- Bind to and antagonise M3 cholinergic receptors on bronchial smooth muscle. This blocks the constricting effect of Ach and also inhibits mucus secretions.
Give an ADR of muscarinic receptor antagonist
Systemic effects avoid as not well absorbed
When would you use muscarinic antagonists?
COPD and Asthma
Name two methylxanthines
What is the mechanism of methylxanthines?
Competitive antagonist of adenosine
What are two complications of methylxanthine use?
What are some indications for the use of leukotriene receptor antagonists?
What is the mechanism of action of leukotriene receptor antagonists?
Antagonise cysLT1 and prevent early and late responses from inflammatory cells
What are two ADRs of Leukotriene Receptor Antagonists?
Headache and gastrointestinal disturbance
Name three corticosteroids
What are three indications for corticosteroids?
Replacement of endogenous corticosteroids
Give a contra-indication for glucocroticoids
What is the mechanism of action of glucocorticoids?
Diffuse into cytoplasm and bind receptor. Complex moves to nucleus and binds HRE, causing inducement and inhibition of transcription.
Give four of the post-transcriptional effects of glucocorticoids
- Upregulate B2 receptors in lungs
- Reduce production of acute inflammatory mediator by inhibiting arachadonic acid processing (Upreg lipocortin which inhibits phospholipase A2, no Prost and leukotrienes prod)
- Reduce number of circulating immunocompetent cells
- Decreases activity of cells involved in chronic stages of inflammation (macrophages/fibroblast)
Give three ADRs of corticosteroids, specifically inhaled
Suppression of HPA acis
What is the main cortiosteroid used in asthma and COPD?
How must you stop corticosteroid therpay?
Slowly, to avoid HPA supression
Outline the indication for a loop diuretic
Name a diuretic used in pulmonary oedema
What is the mech of action of furosemide?
NKCC2 blocker in thick ascending limb of loop of henle
Give four ADRs of loop diuretics
- Hypokalaemia, Ototoxicity, hyponatraemia, hyperuricaemia (can precipitate gout)`
Give two of the main drug-drug interactions of loop diuretics
- Cardiac glycosides – Hypokalaemia caused by loop diuretic potentiate effects of cardiac glycosides, increasing risk of arrhytmias
- Aminoglycosides – Can compound ototoxicity
Give two common bacterial causes of community acquired pneumonia