- The subject had a history of drug or alcohol abuse, or had a positive pre-study urine drug / alcohol breath screen. Abuse of alcohol is defined as an average weekly intake of greater than 21 units or an average daily intake of greater than three units for males and intake greater than 14 units per week or an average daily intake of greater than two units for females. One unit is equivalent to a half-pint (220 mL) of beer or one (25 mL) measure of spirits or one glass (125 mL) of wine.