Plasma levels of a new pelletized form of amitriptyline for maintenance therapy.

Plasma levels of amitriptyline and nortriptyline were measured in volunteers after one week of daily dosage with either 25 mg t.i.d. of standard amitriptyline tablets or a single 75-mg capsule of a new pelletized form of amitriptyline. Concentrations of both compounds were essentially equal at the end of one week's dosage with either dosage form but were somewhat higher throughout the dosing time interval for the pelletized drug.