A study to compare the plasma concentrations of MK0431 at different times in patients with hepatic insufficiency vs healthy control subjects.

Inclusion Criteria:

• If female, non pregnant, BMI less than 40 kg/m2
• Patient has chronic, stable hepatic insufficiency

Exclusion Criteria:

• Patient unwilling to refrain from alcohol and grapefruit juice prior to and shortly after study drug administration
• Patient has diabetes, had a heart attack or stroke, or uncontrolled congestive heart failure during the past 6 months
• Patient has a history of drug or alcohol abuse
• Patient smokes > 10 cigarettes per day
• Patient consumes more that 6 cups of caffeinated beverages per day
• Patient has had surgery, donated blood or participated in another clinical trial within the past 4 weeks