Pharmacokinetics of Buccal and Intranasal Lorazepam in Healthy Adult Volunteers.

PURPOSE:To investigate the plasma-concentration profile of lorazepam when administered by the intranasal and buccal routes to determine their utility for the treatment of prolonged seizures.METHODS:On two occasions separated by at least 7 days washout, 12 healthy adult male volunteers received 2 mg of lorazepam via the intranasal or buccal route. Blood samples were collected at time periods from 0 to 48 h, and pharmacokinetic parameters were determined.RESULTS:Lorazepam was well absorbed from both administration routes; however, there was a more pronounced lag phase with the buccal route and absorption was more rapid from the intranasal route.CONCLUSIONS:Intranasal lorazepam has more favourable pharmacokinetics than buccal lorazepam when considering the need for the rapid blood concentrations required for seizure termination. Further clinical evaluation of this route is required.