Prolongation of response to DMSO by heparin maintenance

Dimethylsulfoxide (DMSO) is an effective treatment of symptomatic patients with detrusor mastocytosis but it is associated with frequent relapses. A group of patients (N = 25) followed for twelve months showed a relapse rate of 59 percent. Our experience with a combination of DMSO and heparin has suggested that the relapse rate may be lower. Heparin is a glycosaminoglycan that may afford protection to the urothelium and may reduce the relapse rate. It is better tolerated than DMSO or a combination of DMSO and heparin and does not produce garlic halitus. It is not associated with coagulation anomalies when administered intravesically. To determine whether or not maintenance therapy with intravesical heparin may reduce relapses we have treated a similar cohort of 25 patients with monthly instillations of 10,000 IU of heparin over a twelve-month period. Both groups were comparable in age, duration of symptoms, severity of symptoms, and response to DMSO. At twelve months only 20 percent of the heparin-treated group had relapsed versus 52 percent of the control group. Furthermore 6 patients (24%) in the follow-up group failed to respond to retreatment with DMSO while all of the heparin maintenance group continued to respond to one or more treatments with DMSO. Thus, it seems that heparin maintenance produces a significant reduction in the relapse rate of patients who respond to DMSO and reduces the number of patients requiring alternative therapy.