24-hour recording of intragastric pH in clinical trials: preconditions, methodology, and standardization strategies.
At present, intragastric pH recording by stomach probe is the standard method for the assessment of the pharmacodynamic effect of newly developed antisecretory drugs, and it is being used increasingly as a diagnostic method. Intraluminal pH can be measured by a variety of different electrode systems, systematic differences among these systems require international standardization of the method. In clinical trials, some recommendations should be followed to standardize the study conditions to assure that repeated measurements are comparable. Standardization of food and liquid intake and a correct positioning of the stomach probe are of paramount importance in assuring that the data are reliable; but there are other factors that may influence the study results, for example, the daily activities of the study participants and the method of data processing. Furthermore, several technical aspects must be considered to guarantee accurate and reproducible recordings, including the type of pH-sensitive electrode and the method of calibration used. Further efforts should be made to create an international standard for the method to assure more comparable study results.
Timmer
W
W
Institut für Klinische Pharmakologie Mannheim, Universitat Heidelberg, Germany.
Wehling
M
M
Theiss
U
U
D015374:Biosensing Techniques; D002138:Calibration; D002986:Clinical Trials as Topic / Q000379:methods*; D004566:Electrodes; D005745:Gastric Acidity Determination / Q000295:instrumentation*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008991:Monitoring, Physiologic / Q000379:methods; D013270:Stomach / Q000502:physiology