The main purpose of this study is to investigate whether the hypotensive effects of an alpha-blocker are increased when VA106483 is given at the same time.

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. Some of the treatments available for nocturia have side-effects which make them unsuitable for elderly patients. These side-effects have not been seen in studies with VA106483, which makes it potentially suitable for treating elderly patients.

Nocturia is commonly associated with Benign Prostatic Hypertrophy (or BPH, a non-cancerous enlargement of the prostate gland, which often results in problems passing water). Of the patients who suffer from BPH, an estimated 40-85% experience the symptoms of waking at night to pass water.

Treatments which are commonly prescribed for BPH include alpha-blockers which work by improving urine flow by a muscle relaxant effect. Alpha-blockers are known to cause hypotension (lowering of blood pressure which can cause dizziness in some patients) . Since it is likely that subjects may be co-prescribed VA106483 and alpha-blockers, the purpose of this study is to determine that giving VA106483 does not increase the hypotensive effects of alpha-blockers

Inclusion Criteria:

• Male aged 65 years of age and above
• No clinically important abnormal physical, laboratory or vital sign findings in the opinion of the Investigator
• Provision of written informed consent to participate
• No recent alpha-blocker therapy
• Not taking any concomitant medication known to be a cytochrome 3A4 inhibitor
• Not taking any prescribed or over the counter medications unless agreed with the Investigator and Sponsor
• No evidence of serious pathology or disease including poorly controlled endocrine disorders; active liver or biliary disease or severe kidney problems; syndrome of inappropriate antidiuretic hormone secretion
• No history of orthostatic hypotension or syncope.
• No known hypersensitivity to the IMP or alpha blocker, including severe lactose intolerance.
• No history of drug or alcohol abuse
• Negative for HIV, hepatitis B or C