Pharmacokinetics of lofepramine and amitriptyline in elderly healthy subjects

Pharmacokinetics of 3 doses (70 mg, 105 mg and 140 mg) of lofepramine were compared with amitriptyline (50 mg) in 6 healthy drug free elderly subjects aged between 65 and 72 years. Pharmacokinetics of lofepramine in the elderly appear to be similar to young adults as published before. Peak plasma lofepramine and amitriptyline concentrations were achieved at about 1 h and 3 h of dosing respectively. Elimination half-life of lofepramine was 2.5 h and that of amitriptyline was 31 h. A 24-fold inter-individual variation in peak plasma lofepramine concentrations was observed, but amitriptyline levels in plasma showed less variation. Pharmacokinetic parameters of amitriptyline were comparable to other published studies involving elderly people. Compared to placebo and lofepramine, amitriptyline produced drowsiness and dry mouth, reduced salivary volume and increased movement reaction time. These effects correlated with the plasma amitriptyline levels.