Asthma and xanthines
Xanthines are a group of chemicals that include caffeine and theophylline, which is sometimes used in the treatment of asthma.
Theophylline
Theophylline is one of the older asthma therapies, and was originally discovered by doctors investigating the efficacy of folk remedies, one of which was coffee. Theophylline is a bronchodilator and acts by relaxing the smooth muscles lining the airways of the lungs, but does so in a more indirect way than beta2 agonists, which are the active ingredient of many asthma reliever medications.
Theophylline used to be the first-line drug of choice for chronic asthma management because it was available in long-acting form, unlike the existing (short-acting) forms of beta2 agonists. However, its use has declined over the past decade due to the increasing availability of drugs which are more effective and which have fewer side effects. Theophylline’s side effects include nausea, anorexia, headache and sleep disturbance, and altered mood and behaviour in children.
Sustained-release theophylline preparations are still sometimes used in the treatment of nocturnal asthma and theophylline's anti-inflammatory effects may still have a role in treating patients with severe persistent asthma who require more than one drug for control. Theophylline is administered orally, usually as tablets or a syrup. Another xanthine, choline theophyllinate, is available as an elixir (oral liquid formulation).
Caffeine
Because of the chemical similarities between caffeine and theophylline, researchers have investigated the potential role of caffeine in the treatment of asthma. Research has shown that caffeine is indeed a weak bronchodilator, and can also reduce respiratory muscle fatigue. Because of this, it may be advisable to avoid caffeine for at least 4 hours prior to lung function testing.
Last Reviewed: 30 October 2003
