Tiazesim (INNTooltip International Nonproprietary Name), or thiazesim (BANTooltip British Approved Name, USANTooltip United States Adopted Name), previously sold under the brand name Altinil, is a heterocyclic antidepressant related to the tricyclic antidepressants (TCAs) which, introduced in 1966 by Squibb Corporation (now Bristol-Myers Squibb), has since been discontinued and is no longer marketed.