Effect of Azithromycin on Oesophageal Hypomotility

Patients with difficulty in swallowing (dysphagia) or with reflux disease are frequently found to suffer from oesophageal hypomotility (weak contractions). Oesophageal motility is currently measured using high-resolution manometry (HRM). This technique has a 36 pressure sensors on a plastic tube to record the pressure in side the oesophagus. Several pharmaceutical agents (prokinetics) can stimulate oesophageal motility. However, use of prokinetics in patients with oesophageal hypomotility led to disappointing results. An explanation for these disappointing results is that inappropriate patients were targeted. The appropriate patient would be the one who still have some viable muscle in the oesophagus that can respond to pharmacological stimuli. In the process of developing treatment strategies in patients with oesophageal hypomotility, testing the preserved capacity of oesophageal muscles could be useful to predict the response of these patients to prokinetic drugs. The following tests have the potential to reveal the preserved capacity of the oesophageal muscle to respond to stronger/medicinal stimuli. 1. \- Multiple rapid swallowing (MRS) of 5ml water boluses stimulates oesophagus. A normal response to MRS requires on the one hand integrity of neural mechanisms and on the other hand a functional oesophageal muscle. 2. \- External abdominal compression can increase the resistance to bolus transport via oesophagus. The normal oesophagus produces contractions of higher amplitude and duration in order to maintain a normal bolus transit. 3. \- Swallowing bread boluses require stronger oesophageal contractions for a successful bolus transit. The purpose of the proposed project is to firstly assess the effect of Azithromycin on oesophageal hypomotility and secondly to evaluate the predictive values of the stimulation techniques in predicting the likelihood the positive response to drug therapy.