Complex sentence: Tiazesim (Altinil) is technically not a TCA, but it is a heterocyclic antidepressant that is very closely related, and similarly to various TCAs, it is no longer marketed.
Split into simpler sentences: Tiazesim (Altinil) is technically not a TCA, but it is a heterocyclic antidepressant that is very closely related. Similarly to various TCAs, it is no longer marketed.