Pharmacokinetics of buccal and intranasal lorazepam in healthy adult volunteers.

ABSTRACT

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.