statMed.org is designed to help students of medicine to learn about differential diagnosis.
It is NOT a clinical decision support tool and should NOT be used to guide decisions about clinical practice.
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It is NOT a symptom checker.
If you are concerned about a medical problem you should immediately seek medical assistance from a doctor.
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Please enter at least one feature (symptom, sign or investigation result) before performing the calculation.
For example, if chest pain and low oxygen saturations were present, but haemoptysis was absent, the features section should look as follows:
To add a feature that is present, start typing and then click the green arrow.
To add the absence of a feature (i.e. a 'negative' finding), start typing then click the red cross.
If you want to remove a feature from the list simply click the grey cross in the box to the right of the feature.
Theophylline, like caffeine, is one of the naturally occurring methylxanthines. The main use of theophyllines in clinical medicine is as a bronchodilator in the management of asthma and COPD
Mechanism of action
The exact mechanism of action has yet to be discovered. One theory suggests theophyllines may be a non-specific inhibitor of phosphodiesterase resulting in an increase in cAMP. Other proposed mechanisms include antagonism of adenosine and prostaglandin inhibition