A Study in Healthy Subjects to Assess How Dosing of Rifampin Affects What the Body Does to a Dose of GW679769 (Casopitant).

Inclusion criteria: * healthy * female subjects who cannot become pregnant * able to swallow and keep down oral medication * can understand and follow the protocol requirements and instructions Exclusion criteria: * smokes at least 4 packs per day in the past 12 months * use of prescription or non-prescription drug(s) * herbal or dietary supplements or vitamins with 14 days prior to first dose of study medication * a clinically relevant abnormality medical condition or circumstance making the subject unsuitable for the study per the study doctor * blood donation in excess of 1 pint within 56 days before dosing of medication * iron deficient * history or drug allergy of study medication * history of drug or alcohol abuse or dependency within the past 6 months * subjects cannot use any nicotine-containing products within the last 6 months * positive for HIV, Hepatitis B or C * active peptic ulcer disease * uncontrolled nausea and vomiting * active infection * heart failure * female who is lactating * female who has a positive pregnancy test