New frontiers for the treatment of noncardiac chest pain: the adenosine receptors.

Emerging data suggest that noncardiac chest pain (NCCP) is a very common disorder of international proportions. In the United States alone, an estimated 69 million patients suffer from NCCP. The clinical spectrum of patients with NCCP being referred to gastroenterologists seems to be changing to those failing to respond acid inhibition therapy or those who may not have gastroesophageal reflux (GER) in the first place. For these individuals there is an important need to find effective therapeutic options. These patients are the subject of the study that appears in this issue of The American Journal of Gastroenterology (Rao et al.,). Rao et al. report data from their tertiary center on consecutive patients with recurrent NCCP failing an 8-wk therapeutic trial of double-dose PPI or lacking evidence of GER on 24-h pH testing. They found that theophylline--a nonspecific adenosine receptor antagonist--when compared with placebo, improved the biomechanical and sensory properties of the esophageal wall and chest pain frequency, severity, and duration. This study underscores the potential role of adenosine receptors in visceral pain.