This study will evaluate any effect of single and repeated administration of GW876008 on the metabolism of midazolam in healthy volunteers.

Inclusion Criteria:

• Healthy males or females.
• Normal ECG.
• Agree to remain in the clinic for the time defined in the protocol.
• Subjects must agree to abstain from alcohol for 24 hours prior to the start of dosing until collection of the final pharmacokinetic sample.

Exclusion Criteria:

• Any serious medical disorder or condition.
• Any history of an endocrine disorder.
• Any clinically significant laboratory abnormality.
• History of psychiatric illness.
• Any history of suicidal attempts or behavior.
• Active peptic ulcer disease.
• Positive faecal occult blood.
• The subject smokes or has smoked or has used any nicotine-containing products in the last six months.
• Women having a positive serum HCG pregnancy test at screening, a positive urine pregnancy test before admission to the Unit during the in-house periods, who are not willing to use acceptable methods of contraception or who are lactating or planning to become pregnant within the three months following the screening visit.