Plasma concentrations of flunitrazepam (Rohypnol) following oral and sublingual administration

Flunitrazepam (Rohypnol) 2.0 mg was given as a single dose by the oral or sublingual route to ten volunteers using a cross-over design. Plasma concentrations of the drug were measured by gas-liquid chromatography for up to 6 hours after administration. The highest mean concentration occurred 45 min after administration irrespective of route. No significant differences were found between the two treatments at any time. Since the sublingual route compares favorably with other routes of administration, these findings suggest that sublingual flunitrazepam is valuable for premedication.