Pilocarpine hydrochloride relieves xerostomia in chronic graft-versus-hostdisease: a sialometrical study

Bone marrow transplantation is considered to be the treatment of choice for various hematological and solid malignancies, as well as for bone marrow f ailure syndromes and some genetic diseases. Unfortunately, a great number o f patients who receive allogeneic BMT suffer from graft-versus-host disease (GVHD) following the procedure. Xerostomia is considered to be one of the most annoying complications of chronic GVHD (cGVHD), and the rapidly growin g number of BMT patients with prolonged survival renders GVHD-related xeros tomia a major clinical problem. As pilocarpine hydrochloride has been shown to relieve xerostomia in other disease categories, we administered pilocar pine hydrochloride 30 mg/day to six cGVHD patients and measured their whole saliva, parotid and submandibular-sublingual flow rates in both resting an d stimulated conditions. Mean values of how rates of whole saliva in restin g conditions at 2 weeks, 2 months and 6 months following administration of pilocarpine hydrochloride 30 mg/day were 0.71 +/- 0.12 ml/min, 0.59 +/- 0.0 7 ml/min and 0.56 +/- 0.11 ml/min, respectively. In stimulated conditions, mean values were 1.7 +/- 0.3 ml/min, 1.0 +/- 0.17 ml/min and 0.94 +/- 0.21 ml/min, respectively. The mean values of whole saliva flow rates under both conditions represented an increase of 224-284% and 134-247%, respectively (P < 0.01). The pattern and magnitude of parotid and submandibular-sublingu al flow rate increases following pilocarpine hydrochloride administration w ere similar. Patients were followed for 6 months and demonstrated increased levels of secretion, with some reduction after the initial peak values, Th e medication was discontinued at 2 months and reinstated after 2 weeks in t hree patients. This resulted in rapid flow rate reduction followed by anoth er profound increase. Contrary to the sialometrical analysis, the subjectiv e scoring showed no fluctuations during the study period. We discuss these results in the context of the clinical experience of xerostomic patients in whom even a minute increase in secretion may be significant, Our results d emonstrate that objective and subjective relief from xerostomia in cGVHD pa tients can be achieved with the routine oral administration of pilocarpine hydrochloride.