In the late 1950s, imipramine was noted to be effective for the symptomatic treatment of depression. A number of chemical congeners of imipramine have been synthesized and tested for antidepressant properties; they are collectively known as TCAs. The TCAs are no longer considered first-line agents in the treatment of depression because of their prominent side effects and the need to monitor drug blood levels to avoid toxicity.
Seven TCA drugs are available in the United States for treatment of major depression. They are generally categorized as tertiary or secondary amines. Tertiary amines include imipramine (Tofranil), amitriptyline (Elavil), trimipramine (Surmontil), and doxepin (Sin-equan). Desipramine (Norpramin), nortriptyline (Pam-elor), and protriptyline (Vivactil) are secondary amines.
Clomipramine (Anafranil) also a member of the tri-cyclic family, possesses similar pharmacology and anti-depressant efficacy. This agent, however, has Food and Drug (FDA) approval only for use in the treatment of obsessive-compulsive disorder and is not included in this discussion of antidepressant drugs.
Maprotiline (Ludiomil) and amoxapine (Asendin) are heterocyclic antidepressant agents that are not members of the tricyclic family. However, their pharmacology is so similar to that of the tricyclic amines that they are included for discussion purposes with this class of agents. Desipramine and nortriptyline are major metabolites of imipramine and amitriptyline, respectively.
Was this article helpful?