Predicting Refractory Detrusor Overactivity: Are There any Clues at Diagnosis

Approximately one-third of patients diagnosed with detrusor overactivity (DO) will be refractory to treatment with antimuscarinic drugs. In this study, we examined baseline clinical details and history of urinary tract infection (UTI), urodynamics parameters, urinary pH and ATP in voided urodynamic fluid for any prognostic factors that would allow prediction of the refractory state at the time of diagnosis. At follow-up (2 to 5 years), patients were characterised as responders or non-responders based on a >50% decrease in urge leaks and voids per 24 hours. Of the 61 patients who met the inclusion criteria, follow-up revealed that 25% of these did not respond to antimuscarinic therapy. There were no significant differences in urodynamic parameters in responders compared to non-responders. Patients with a greater number of leaks/week at baseline and a history of UTI were more likely to be non-responsive to antimuscarinic therapy. There was no difference in urinary pH or ATP concentration in voided urodynamic fluid in the two groups. The results indicate that severity of leakage at baseline history and a history of recurrent UTI appears to be poor prognostic features in patients with DO. These may be associated with the development of the ‘refractory’ state.