Efficacy of Pilocarpine and Bromhexine in Improving Radiotherapy-induced Xerostomia

Background and aims. Xerostomia is one of the most common complications of head and neck radiotherapy. The aim of this study was to evaluate and compare the efficacy of pilocarpine and bromhexine in improving radiotherapy-induced xerostomia and its associated symptoms. Materials and methods. In this single-blind, randomized crossover study, pilocarpine and bromhexine tablets were used by twenty-five patients suffered from xerostomia, with a medical history of head and neck radiotherapy. At step A, the patients were treated with pilocarpine for 2 weeks. In addition, they were asked to take bromhexine for 2 weeks with a one-week washout period. At step B, the inverse process was conducted (first bromhexine, then pilocarpine). Whole resting saliva was collected from patients before and after receiving each medication by precise measurements. Then, efficacy of the two drugs in the treatment of xerostomia and its related oral complications was evaluated using questionnaires by Dichotomous format. The results were statistically analyzed using t-student and Fisher's exact and chi-squared tests. Statistical significance was set at P<0.05. Results. The difference between saliva secretion rates before and after medications was not significant for bromhexine users at two steps of the study (P=0.35); however, it was significant for pilocarpine users (P=0.0001). Users of both drugs showed significant differences in improvement of xerostomia, chewing, swallowing, tasting and mouth burning. Conclusion. Pilocarpine is probably more effective in improving xerostomia and its associated problems compared with bromhexine, although the use of the latter was also shown to ease some of the consequences of radiotherapy in the head and neck region.