I bet this is the drug they asked you about: Rohypnol.
You can find some good information here about this medication...
http://www.whitehousedrugpolicy.gov/publications/factsht/rohypnol/
Rohypnol is the trade name for the drug flunitrazepam, a benzodiazepine (central nervous system depressant) like Valium, yet 10 times more potent. It is widely available in Europe, Mexico, and Colombia, but is neither manufactured nor approved for sale in the United States.
Illicit use of Rohypnol began in the 1970s in Europe and appeared in the United States in the early 1990s. Much of the concern surrounding Rohypnol is its abuse as a "date rape" drug. Rohypnol is a tasteless and odorless drug and, until recent manufacturer efforts, dissolved clear in liquid, which masked its presence. Rohypnol comes in pill form and is usually sold in the manufacturers bubble packaging, which can mislead users in the United States into believing the drug is safe and legal. Since February 1999, reformulated Rohypnol tablets, which turn blue in a drink to increase visibility, have been approved and marketed in 20 countries. The old noncolored tablets are still available, however. In response to the reformulated blue tablets, people who intend to commit a sexual assault facilitated by Rohypnol are now serving blue tropical drinks and punches in which the blue dye can be disguised.
Rohypnol can be ingested orally, snorted, or injected. It is often combined with alcohol or used as a remedy for the depression that follows a stimulant high. The effects of Rohypnol begin within 15 to 20 minutes of administration and, depending on the amount ingested, may persist for more than 12 hours. The drug�s metabolic properties are detectable in urine for up to 72 hours after ingestion.
Under Rohypnol, individuals may experience a slowing of psychomotor performance, muscle relaxation, decreased blood pressure, sleepiness, and/or amnesia. Some of the adverse side effects associated with the drugs use are drowsiness, headaches, memory impairment, dizziness, nightmares, confusion, and tremors. Although classified as a depressant, Rohypnol can induce aggression and/or excitability.