Intravenous versus oral administration of amitriptyline in patients with major depression

Antidepressants can be administered by different routes, Advantages for eit her the oral or the intravenous administration have been suggested from pha rmacokinetic as well as from clinical points of view. Controlled comparison studies of the two routes do not provide unequivocal recommendations. In t his investigation, amitriptyline was studied over a 4-week period consistin g of a 2-week, double-blind/double-dummy phase with either oral (150 mg/day ), high-dose intravenous (150 mg/day), or medium-dose intravenous (100 mg/d ay) treatment and a a-week phase of open oral treatment in 80 patients with major depression. A psychopathologic assessment was made using the Hamilto n Rating Scale for Depression, the Clinical Global Impressions Scale, the v on Zerssen's "Befindlichkeitsskala," an adjective checklist, and a Visual A nalog Scale. No significant differences were found concerning the mean scor es of the rating scales or time of onset of action in the physicians' ratin gs. In the patients' self-ratings, there was an earlier therapeutic effect in the high-dose intravenous group. The number of improvers after 7 days wa s significantly higher in the high-dose intravenous group compared with bot h other groups. After 14 days, no significant differences in the numbers of improvers and responders between groups were detected. The results of this study do not clearly favor one of the tested options. The main differences found in this study seem to be dose-related rather than differentiating be tween oral and intravenous routes of administration.