Intravesical instillation of drugs in patients with detrusor hyperactivity.

Intravesical administration of drugs may inhibit detrusor hyperactivity. Intravesical drug administration might be clinically useful in patients with detrusor hyperactivity, particularly in patients with neurogenic etiology using CIC. The therapeutic usefulness has to be documented in controlled studies. The mechanisms of action and the potency of the individual substances can not be decided from the present investigations. However, no finding contradicts that the known pharmacological properties of the drugs used are responsible for the effects noted. The different responsiveness to intravesical drugs between patients with neurogenic and non-neurogenic etiology might be due to pathophysiological differences. By intravesical administration of drugs the tissue concentration obtainable within the bladder wall is higher than the one obtainable by systemic administration. The optimal relation between tissue and serum concentrations can be achieved by a careful preparation of the drug solution and by titration of the dose. No side effects were found in the studies and no clinically significant side effects have been reported by other investigators. The risk of late side effects is unknown. The serum concentrations found in man and rabbit, after intravesical instillation of terodiline, indicate that by this route of administration terodiline may be safely used, in spite of the side effects reported at systemic administration. For evaluation of the diagnostic usefulness further documentation of the mechanisms of action and of the pathophysiology are needed.