Mark Colbridge discusses the difficulties of establishing a dosage regime for theophylline without inducing toxic effects

Theophylline is a naturally occurring methylxanthine, belonging to the same family as caffeine. Although it has seen a decline in popularity over recent years, it is still prescribed for the treatment of asthma and chronic obstructive pulmonary disease. As well as its bronchodilatory effects, theophylline also has anti-inflammatory and immunomodulatory actions and increases respiratory drive. These findings may well reverse the downward trend in prescribing.