What are the classes and examples of antidepressants?

Classes and Examples of Antidepressants

Second-generation antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), are generally considered first-line therapy for depression, with specific examples including fluoxetine, sertraline, paroxetine, citalopram, escitalopram, and fluvoxamine. 1

Major Antidepressant Classes

Selective Serotonin Reuptake Inhibitors (SSRIs)

• Examples: Fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), escitalopram (Lexapro), and fluvoxamine (Luvox) 1
• These medications work by blocking serotonin reuptake in the presynapse, increasing serotonin levels in the synaptic cleft 2
• SSRIs have comparable clinical efficacy to each other, with similar effectiveness demonstrated across paroxetine, fluoxetine, and sertraline in primary care settings 3
• Weight considerations: Fluoxetine and sertraline are associated with weight loss in short-term use and weight neutrality with long-term use, while paroxetine carries the greatest risk for weight gain within the SSRI class 1

Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)

• Example: Venlafaxine 1
• SNRIs are slightly more likely than SSRIs to improve depression symptoms but are associated with higher rates of adverse effects 1
• Preferred medication for older adults alongside SSRIs 1

Tricyclic Antidepressants (TCAs)

• Examples: Amitriptyline, imipramine, desipramine, maprotiline, clomipramine 1
• TCAs have a number needed to treat ranging from 7 to 16 1
• Important distinction: Dual-acting TCAs (clomipramine and amitriptyline) show superior efficacy in severe or hospitalized depression compared to more selective TCAs 1
• Amitriptyline carries the greatest risk for weight gain within the TCA class 1

Monoamine Oxidase Inhibitors (MAOIs)

• Example: Tranylcypromine 4
• MAOIs are closely associated with weight gain 1
• Critical safety concern: MAOIs are contraindicated with numerous other antidepressants including all SSRIs, SNRIs, TCAs, and other MAOIs due to risk of hypertensive crisis and serotonin syndrome 4
• Require medication-free periods of at least one week when switching to or from other antidepressants 4

Norepinephrine and Dopamine Reuptake Inhibitors

• Example: Bupropion 1
• Bupropion is the only antidepressant consistently shown to promote weight loss by suppressing appetite and reducing food cravings 1
• Caveat: Bupropion is activating and can exacerbate anxiety or be inappropriate for patients with bipolar disorder 1

Other Second-Generation Antidepressants

• Examples: Mirtazapine, nefazodone, trazodone, vilazodone, vortioxetine, amoxapine, maprotiline 4
• Mirtazapine is preferred for older adults but is closely associated with weight gain 1

Clinical Selection Considerations

For older adults, the American Academy of Family Physicians recommends a "start low, go slow" approach with preferred medications including citalopram, escitalopram, sertraline, mirtazapine, and venlafaxine 1

For breastfeeding mothers, sertraline and paroxetine transfer to breast milk in lower concentrations than other antidepressants 1

Common pitfall: About two-thirds of patients receiving second-generation antidepressants experience at least one adverse effect during treatment, with nausea and vomiting being the most common reasons for discontinuation 1