tokens: The free fraction of amitriptyline ( AT ) , measured by equilibrium dialysis in plasma from 29 AT - treated depressed patients , was 5 . 4 - 9 . 8 % ( mean 7 . 7 % ) , which was the same as the values in 26 healthy controls ( 4 . 9 - 9 . 6 % , mean 7 . 6 % ) .