What are the effects of symathomimetic drugs that are used in the treatment of acute asthma?
- Relaxation of smooth bronchial muscle;
- Restriction of the release of bronchonostricting mediators from mast cells;
- Increase in ciliary activity in he bronchi increasing mucociliary ransport;
Inhaled b1-agonists are the modern mainstay of treatment in acute asthma. Tue or False?
False. Beta2-agoinsts are used in the treatment of acute asthma.
Nebulized Salbutamol is more effecive than metered inhaler. This is why it is reserved for non-responsive cases. True or False?
False. Nebulized delivery is not more effective than MDI delivery. The droplets are larger in size this makes the delivery more difficult. This is the reason why nebulized doses have to be higher.
Nebulized delivery is reserved for patients who are uunable to coordinate breath holding and use of the MDI.
Salbutamol is a racemic misx of R- and S- rotatioing isomers. True or False?
True. Salbutamol is a racemic mixture of R- and S- isomers.
R-isomer causes the effect of salbutamol. True or Fals?
True. It is the R-isoform of Salbutamol that causes the bronchodilator effect in asthma.
Purified R form of Salbutamol is more effective than the racemic mixture. True or False?
False. The latest clinical research data shows no difference in outcomes of use of racemic mix and purified R- form of Salbutamol.
Newer, long acting selective beta-agonists show promising results in the treatment of acute asthma exacerbations. True or False?
False. Long acting beta agoinsts should not be used in the treatment of acute asthma.
What is the mechanism of anti inflammatory effect of long acting beta agoinsts?
Long acting beta-agonists have no anti inflammatory effect.
What is the mechanism behing long acting beta-agoinsts use in asthma.
Due to their high lipid solubility, these agents dissolve in high cincentration in the muscle cell membrane and possibly attach to mooring molecules nearby adrenoceptors.
These agents also interact with corticisteroids to improve asthma control.
Long acting highly selective beta agonsts can are can be used for monotherapy of mild asthma as they accumulate in high concentrations in the membrane of bronchial smooth muscle cells and exert longer action..
Althought the mechanism of actiono is correct, long acting beta-agonists should not be used as monotherapy as they do not affect inflammation component of asthma.
What are methylxanthines? Name some of them.
Methylxanthines are a group of drugs used in the treatment of asthma? theophylline (Aminophylline), Theobromine, Caffeine.
What are the mechnisms of action behind methylxanthines?
PDE4 inhibition. Methylxanthines inhibit PDE4 which results in decrease in realease of inflammation mediators (i.e. chemokines and cytokines) and consequently margination and activation of immune cells;
Inhibition of cell serface receptors for Adenosine. Methylxanthines inhibit cell surface receptors for Adenosine, which results in lower response to adenosine stimulation and relieves bronchoconstriction;
Deacetylation of hstones. Methylxanthines enhance deacetylation of histones. Acetylated histones stimulate inflammatory gene transcription.
Most common effects of Thephyllin are.
- Abdominal cramps;
- Cardiac rhythm abnormalities;
What agents are useful in the management of cardiac arrhythmias nduced by Theophyllin?
Beta-blockers are used in the management of cardiac arrhythmias from Teophylline.
What are the antimuscarinic agent options in the management of acute and cronic asthma?
For acute asthma exaccerbation - Ipratropium Bromide (quaternary antimuscarinic agent) - an aerosol inhaled agent.