- Patients who have an average weekly alcohol intake that exceeds 21 units per week (males) and 14 units per week (females) or patients unwilling to stop alcohol consumption for the duration of the drug interaction phase (Periods 1 and 2) of the study (1 unit = 12 oz or 360 mL of beer; 5 oz or 150 mL of wine; 1.5 oz or 45 mL of distilled spirits).