Paxil vs. Viibryd

See how Paxil and Viibryd compare on approved uses, dosing, side effects, and cost.

Key Takeaways

  • Paxil is an SSRI approved for depression and several anxiety disorders, while Viibryd is a newer SPARI approved only for major depressive disorder.

  • Viibryd requires a two-week titration and must be taken with food, while Paxil has a simpler dosing range but a stronger risk of drug interactions through CYP2D6.

  • Both carry a boxed warning for suicidal thoughts in young people, but Paxil is generally more affordable while Viibryd is linked to lower rates of sexual side effects.

Paxil vs. Viibryd Drug Summary

Paxil

Paxil (paroxetine) is a selective serotonin reuptake inhibitor (SSRI) used to treat major depressive disorder, OCD, panic disorder, social anxiety disorder, generalized anxiety disorder, and PTSD. It's taken as a tablet once daily, with the dose adjusted over time based on response.

Viibryd

Viibryd (vilazodone) is a serotonin partial agonist and reuptake inhibitor (SPARI) approved only for major depressive disorder in adults. It's taken as a tablet once daily with food, starting at a low dose and increasing over two weeks to the target dose.

Paxil vs. Viibryd Side Effects

Paxil

Most common
nausea (up to 26%)
somnolence (up to 23%)
dry mouth (up to 18%)
asthenia (up to 15%)

Viibryd

Most common
diarrhea (up to 28%)
nausea (up to 23%)
insomnia (6% to 7%)
vomiting (up to 5%)

Paxil vs. Viibryd Dosage

Paxil

Dosage
Dosage Table
STAGE DOSE WHEN
Starting dose 20 mg once daily At the start
Maximum dose 50 mg once daily If needed
Dose changes 3 increases As tolerated

Viibryd

Dosage
Dosage Table
STAGE DOSE WHEN
Starting dose 10 mg once daily Days 1-7
Maximum dose 40 mg once daily Day 15 onward
Dose changes 2 increases Every 7 days

Paxil vs. Viibryd Indications

Paxil

Paxil is FDA-approved for a broad range of conditions beyond depression, including OCD, panic disorder, social anxiety disorder, generalized anxiety disorder, and PTSD. This makes it a common choice when depression overlaps with an anxiety-related condition.

  • Major depressive disorder

  • Obsessive-compulsive disorder

  • Panic disorder

  • Social anxiety disorder

Viibryd

Viibryd's only FDA-approved use is major depressive disorder in adults. Any use for anxiety or other conditions is off-label and not supported by FDA-reviewed trial data specific to those conditions.

  • Major depressive disorder in adults

  • Not approved for pediatric depression

  • Off-label use for anxiety disorders (not FDA-approved)

  • Off-label use for premenstrual dysphoric disorder (not FDA-approved)

Paxil vs. Viibryd Pros and Cons

Paxil

Paxil has decades of clinical use and covers more approved conditions than Viibryd, but its strong CYP2D6 inhibition means many other medications need dose adjustments. Its short half-life can also make stopping the drug harder than with other SSRIs.

Pros

  • FDA-approved for 6 different conditions, not just depression

  • Available in tablet, extended-release, and liquid forms

  • Decades of real-world safety data since its 1992 approval

Cons

  • Strong CYP2D6 inhibitor, causing many drug interactions

  • Short half-life linked to more noticeable discontinuation symptoms

  • Not approved for use in pediatric patients

  • Higher reported rate of sedation-type effects (up to 23%)

Viibryd

Viibryd's dual mechanism may cause less sexual dysfunction than typical SSRIs, but it must be taken with food and carries a higher, less generic-friendly price. Its FDA approval is also narrower than Paxil's, covering only major depressive disorder.

Pros

  • Distinct mechanism (partial 5-HT1A agonism) tied to lower sexual side effect rates

  • Simple 2-week titration schedule to reach target dose

  • Lower CYP2D6 interaction risk than Paxil, easing use with other drugs

Cons

  • Must be taken with food for proper absorption

  • No widely available generic despite FDA generic approval

  • Higher monthly list price ($380-$650) than Paxil ($300-$310)

  • Only approved for major depressive disorder, not anxiety disorders

Common Symptoms and Related Diseases You Can Explore

Explore a range of common symptoms the Doctronic Symptom Checker can help you understand.