VA106483 Dose Response Study in Elderly Males

VA106483 is intended to be used as a treatment for patients suffering from nocturia (defined as waking to urinate at least once per night between periods of sleep). Nocturia is a condition that often worsens as sufferers get older. This may be due to an over-active bladder muscle, the bladder being able to hold less urine at night-time or over production of urine in the bladder at night. 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. Subjects will be water-loaded, dosed with either VA106483 or placebo and then urine production will be monitored to assess any anti-diuretic effect.