Mechanism of action of theophylline in Bronchial asthma include all of the following Except -
Ans. is 'd' i.e., Beta-2 receptor stimulationo Pneumonia and CHF (Cardiopulmonary disease) require dose reduction (not increased dose).Theophyllineo Theophylline is one of the three naturally occurring methylated xanthine alkaloids (methyl xanthines) - Caffeine, theophylline and theobromine,o Mechanism of actiona) Inhibition of phosphodiesterase -| degradation of cAMP or cGMP|bronchodilatation - increased intracellular cAMP or cGMP.Blockade of adenosine receptorsRelease of Ca+2 from sarcoplasmic reticulum especially in skeletal and cardiac muscles.Recently it has been found that theophylline at low doses exert antiinflammatory action by activating a nuclear enzyme, histone deacetylase-2.Proposed mechanisms of action of theophyllineo Phosphodiesterase inhibition (Non selective)o Adenosine receptor antagonism (A1 A2)o Increased histone Deacetylase activity (|ed efficacy of corticosteroids)o Inhibition of intracellular calcium releaseo Stimulation of catecholamine releaseo Inhibition of NF - a B translocation into the nucleus (|nuclear translocation)o Mediator inhibition (Prostaglandins, TNF a)
Phosphodiesterase inhibition
Adenosine receptor antagonism
Increased histone deacetylation
Beta-2 receptor stimulation
Asthma