Heart arrhythmia theophylline

Purine receptors Adenosine, AMP, ADP and ATP can act extracellularly as hormones or transmitters, too In particular, adenosine receptors that occur in the heart, the brain, and the lung are the targets of theophylline and caffeine. Adenosine itself is being used for the treatment of a special type of cardiac arrhythmia. 

Established interactions. The CSM in the UK advises that, as potentially serious hypokalaemia may result from beta2 agonist therapy, particular caution is required in severe asthma, as this effect may be potentiated by theophylline and its derivatives, corticosteroids, diuretics, and by hypoxia. Hypokalaemia with concurrent use of thiazide and loop diuretics may be reduced or even abolished by the addition of spironolactone or high-dose triamterene. Plasma potassium levels should therefore be monitored in patients with severe asthma. Hypokalaemia may result in cardiac arrhythmias in patients with ischaemic heart disease and may also affect the response of patients to drugs such as the digitalis glycosides and an-tiarrhythmics. 

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