Antidepressants: Know Your Options

About 2 dozen antidepressant medications are approved by the FDA for use in the U.S. Some date back to the 1950s, while others have been released in the past few years. Some are like siblings, with very similar chemical characteristics, while others are more like distant cousins with very different pharmacologic properties. Some of the shorter-acting medications are available in extended-release pill formulations that release the drug over a longer period of time. All of the antidepressants are available in tablet or capsule form, a few are made in liquid preparations, and one is available as a patch.

Antidepressants affect neurotransmitters in the brain that are believed to be involved in the regulation of mood, although exactly how and why they work is not fully understood. The two key neurotransmitters influenced by antidepressants are norepinephrine and serotonin, although some affect dopamine. Antidepressants may block the reuptake of these neurotransmitters or interact with neurotransmitter receptors at synapses within the brain.

The earliest antidepressants were the tricyclic compounds (TCA), named for their chemical structure, and the monoamine oxidase inhibitors (MAOIs). The MAOIs act by interfering with the action of monoamine oxidase, an enzyme that ordinarily breaks down the beneficial neurotransmitters such as serotonin and norepinephrine. By slowing this breakdown, MAOI allows the neurotransmitters to remain active longer. While both these early classes of drugs are effective antidepressants, the TCAs and MAOIs are both associated with bothersome side effects, sometime serious ones.

New types of antidepressants rapidly became available in the 1980s, especially with the popularity of the selective serotonin receptor inhibitors (SSRI) like Prozac. Over the past few decades, selective serotonin and norepinephrine reuptake inhibitors (SNRI), serotonin modulating antidepressants (SMA), a dopamine and norepinephrine reuptake inhibitor (DNRI), a tetracyclic antidepressant, a newer type of MAOI, and a norepinephrine and selective serotonergic antidepressant (NaSSA) were approved and marketed. All have certain advantages and disadvantages.

Here is a list of the antidepressants currently available in the U.S. I've listed the generic names along with the primary brand name, and the antidepressant type of each:

Generic Name	Brand Name	Type
Amitriptyline	Elavil®	TCA
Bupropion	Wellbutrin®	DNRI
Citalopram	Celexa®	SSRI
Clomipramine	Anafranil®	TCA
Desipramine	Nopramin®	TCA
Doxepin	Sinequan®	TCA
Duloxetine	Cymbalta®	SNRI
Escitalopram	Lexapro®	SSRI
Fluoxetine	Prozac®	SSRI
Fluvoxamine	Luvox®	SSRI
Imipramine	Tofranil®	TCA
Isocarboxacid	Marplan®	MAOI
Maprotiline	Ludiomil®	Tetracyclic
Mirtazapine	Remeron®	NaSSA
Nortriptyline	Pamelor®	TCA
Paroxetine	Paxil®	SSRI
Phenelzine	Nardil®	MAOI
Protriptyline	Vivactyl®	TCA
Selegiline	Emsam®	MAOI
Sertraline	Zoloft®	SSRI
Tranylcypromine	Parnate®	MAOI
Trazodone	Desyrel®	SMA
Trimipramine	Surmontil®	TCA
Venlafaxine	Effexor®	SNRI