The only antidiuretic approved for the treatment (in some countries) of nocturia is the peptide drug, desmopressin. However, as it can cause hyponatraemia in a proportion of patients above the age of 65 years it is contra-indicated in the elderly. This side-effect has not been observed with VA106483, making it potentially suitable for treating the elderly. The purpose of this study is to confirm that duration of action of VA106483 can be effectively controlled by dose and therefore that satisfactory clinical outcome in the treatment of nocturia can be achieved by individual dose titration.