Oral ranitidine and duration of gastric pH >4.0 in infants with persisting reflux symptoms

Ranitidine is a drug commonly used in pathological gastro-oesophageal reflux (GOR) in infants. Non-responsiveness has been reported. Data regarding the effect of ranitidine on oesophageal acid exposure and reduction of gastric acid secretion are limited in this age group.

To evaluate oesophageal acid exposure, reduction of gastric acid secretion and histology of oesophageal biopsies in infants who clinically do not respond to oral ranitidine.

103 infants (mean age 3.3 +/- 1.8 mo) with persisting symptoms of reflux despite administration of ranitidine, prescribed previously by a referring physician, at a mean (SD) dose of 9.4 (+/- 3.3) mg/kg/d for at least 2 wk (mean 30 d), were submitted to a 24-h pH study and oesophageal biopsy (90/103 patients).

Histological oesophagitis was present in 21/90 (23%). The oesophageal reflux index (RI) was >5% and >10% in 21/103 (20%) and 6/103 (6%) infants, respectively. Gastric pH was >4.0 during <50%, >50%, >75% and >90% of the duration of pH monitoring in 33/103 (32%), 70/103 (68%), 22/103 (21%) and 7/103 (7%), respectively. By simple regression analysis, the dosage of ranitidine correlated with the oesophageal RI (r = 0.21; p = 0.05), but not with the duration of time gastric pH was >4.0 (r = 0.09; p = 0.39). Histological oesophagitis did not correlate with ranitidine dosage, duration of treatment, duration gastric pH was >4.0 and oesophageal reflux index.

Some infants presenting with symptoms assumed to be GOR and acid related fail to respond to acid suppression with ranitidine, either because they need better acid suppression or because the symptoms are not acid related.