Evaluation of the influence of bethanechol chloride in salivary composition and flow rate in irradiated patients in the head and neck region

Abstract

In 2010, Jaguar et al. showed the efficacy of the prophylactic use of bethanechol chloride (BC) during radiotherapy in the head and neck region, clinically reducing the intensity of xerostomia. However, its action in irradiated patients who present xerostomia has not yet been determined. The present study will evaluate the efficacy of BC in patients irradiated in the head and neck region. Salivary composition subsequent to drug administration will also be assessed. This study will involve 50 patients irradiated in the head and neck region, who have been to the Liga Interdisciplinar das Neoplasias Bucais of the School of Dentistry at University of Sao Paulo complaining of dry mouth. All of them will be informed of the research and will be asked to sign a term of informed consent in order to participate. A total dose of 50mg of bethanechol chloride per day will be prescribed. Patients will be instructed to take one 25mg tablet at 8:00 A.M. and another 25mg one at 8:00 P.M., for a period of 3 months. Xerostomia will be assessed through subjective questions put to patients every two weeks (for three months from the beginning of the use of bethanechol) and classified in accordance with EISBRUCH et al. (2003). Sialometry and a Quality of Life Questionnaire will also be evaluated. The whole salivary flow rate will be calculated through collections of both non-stimulated whole saliva and stimulated saliva (mechanical method). For the biochemical analysis of the saliva samples, the buffering capacity and the pH of each sample will be measured immediately after collection. The samples will be frozen at -80°C, to subsequently be analyzed for concentration of total protein, sialic acid and salivary ions, as well as for the determination of salivary amylase and peroxidase activities. (AU)