Facebook Pixel Code
Section banner image
Paediatric Laboratory Medicine

Benzodiazepine Identification (U)

Clinical Significance

Rohypnol is the trade name for the drug flunitrazepam, a benzodiazepine (central nervous system depressant) like Valium, yet 10 times more potent. 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. Since February 1999, reformulated Rohypnol tablets, which turn blue in a drink to increase visibility, have been approved and marketed in 20 countries.

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.

Test Name

Benzodiazepine Identification (U)

Alternate Name/ Synonym

Rohypnol, Flunitrazepam

Test Code


Drug Class

Date Rape Drugs





External Proficiency Testing

Not applicable

Turn Around Time

Daily, Stat

Specimen Type


Minimum Specimen Requirements

1.0 mL

Optimal Collection Time



4°C (transport with a cool pack if possible)

Approval is not required

CPT Codes


Shipping and Contact Information

The Hospital for Sick Children
Rapid Response Laboratory
170 Elizabeth Street, Room 3642
Toronto, ON
M5G 2G3
Phone: 416-813-7200
Phone: 1-855-381-3212

Therapeutic Range

Not detected

Critical Values

Not detected < 25 ug/L

Positive > 26 ug/L