Biotransformation of amitriptyline in man: interaction with phenothiazines

The biotransformation modification of amitriptyline by phenothiazines has been studied in 65 depressive inpatients. Thirty-four of them were treated with oral amitriptyline and 31 with a combination of amitriptyline and phenothiazine. Urinary and plasmatic results showed a decrease in hydroxylated metabolites of amitriptyline (OHAMTc and OHAMT) in patients with added phenothiazine.