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
Viibryd
Paxil vs. Viibryd Dosage
Paxil
Viibryd
| 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 |
| 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
| 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
| 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
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