7. Subjects with a positive urine drug screening [cocaine, amphetamines, tetrahydrocannabinol (THC), benzodiazepines and opiates] at Visit 1 (Day -7). Note: Subjects with a positive urine drug screen for THC may be retested in 7 days and enrolled if they a) continue to meet inclusion/exclusion criteria and b) have a negative urine drug screen upon retest.