• Two dosage schedules of amitriptyline hydrochloride, once daily vs three times daily, were compared in a group of 124 nonpsychotic depressed outpatients. After four weeks of treatment, patients on the once daily schedule had improved significantly more than patients receiving multiple doses on both physician and patient measures. The two groups did not differ in their attrition rates nor in reporting of side effects. Since treatment response to the tricyclic antidepressants is often delayed, once-daily dosage seems to offer a distinct advantage over more conventional multiple doses in depressed outpatients.
Weise CC, Stein MK, Pereira-Ogan J, Csanalosi I, Rickels K. Amitriptyline Once Daily vs Three Times Daily in Depressed Outpatients. Arch Gen Psychiatry. 1980;37(5):555–560. doi:10.1001/archpsyc.1980.01780180069007