Administración sublingual de alprazolam. Estudio farmacocinético. Resultados preliminares

The main pharmacokinetic parameters were assessed after the sublingual administration of a single 0.5-mg alprazolam tablet to 23 healthy volunteers (13 men), aged 21 to 50 years. Blood samples were taken at: 0 (before); 4; 6; 8; 10; 12; 15; 20; 30; 45; 60; 120; 180; and 240 minutes and 30 hours after the administration of the tablet in order to determine alprazolam plasma levels. Alprazolam plasma levels were assessed by highpressure liquid chromatography (HPLC). The area under the curve (AUC 0 - 1 5 min AUC 0 - 4 h and AUC 0 - 3 0 h ) were 0.12; 22.09 and 109.05 ng/ml/h respectively. C m a x (6.79 ng/ml/h) was obtained at 2 hours (T m a x ). Half life (T 1 / 2 ) and elimination constant (K e l ) were 11.9 h and 0.058 l/h respectively. The use of a formulation that provides a fast absorption might be helpful for those patients suffering from acute anxiety disorders who may benefit from a rapid onset of action of the prescribed drug.