The influence of pilocarpine and biperiden on pH value and calcium, phosphate, and bicarbonate concentrations in saliva during and after radiotherapyfor head and neck cancer

Objective. The purpose of the present study was to investigate the influenc e of parasympathomimetic pilocarpine and anticholinergic biperiden on saliv ation, pH value, and calcium, phosphate, and bicarbonate concentrations in saliva in patients irradiated for malignant tumors of the head and neck reg ion. Study design. Sixty-nine patients were randomly assigned into 3 groups. Gro up A consisted of patients receiving pilocarpine, group B of those who were receiving biperiden during radiotherapy and pilocarpine for 6 weeks after its completion, and group C comprised patients receiving neither of the men tioned drugs. The quantity of secreted unstimulated saliva, its pH value, a s well as calcium, phosphate, and bicarbonate concentrations in saliva were measured before the beginning of radiotherapy, after 30 Gy of Irradiation, at completed irradiation, and 3, 6, and 12 months after completion of radi otherapy. Results. Saliva secretion was found to be the least affected in the group o f patients receiving biperidene throughout the course of radiotherapy. One year after completion of therapy, the quantity of secreted saliva could onl y be measured in the patients receiving biperiden during radiotherapy; it a mounted to 16% of the average initial quantity of saliva secreted before th e beginning of irradiation. In all 3 groups of patients, mean pH value decr eased during radiotherapy and started to increase again after completion of irradiation. In group B the decrease in pH value after radiotherapy was st atistically significantly smaller than that in group C (P=.01). During and after irradiation, calcium concentration was increased in all 3 groups of p atients. Phosphate concentration decreased during radiotherapy in all 3 gro ups. In group B it started to increase again 3 months after completion of r adiotherapy. Bicarbonate concentration showed a slight increase during radi otherapy and started to decrease again after completion of irradiation. Conclusion. The results of our study indicate that the inhibition of saliva secretion during radiotherapy and its stimulation after completion of trea tment can contribute not only to some preservation of the quantity of saliv a but also to at least partial preservation of its quality in terms of pH v alue and calcium, phosphate, and bicarbonate concentrations.