 7. A positive pre-study drugalcohol screen. A minimum list of drugs that will be screened for include amphetamines, barbiturates, cocaine, opiates, cannabinoids and benzodiazepines. A positive pre-study drug screen, for medications that are prescribed to a subject for pre-existing conditions, may be allowed if in the opinion of the Investigator and Medical Monitor the medication will not interfere with the study procedures or compromise subject safety. 