Generic Name

Dayvigo

Mechanism

Dayvigo exerts its antidepressant effects through a multifaceted action on the serotonergic system:
• 5‑HT1A partial agonist – stimulates postsynaptic receptors, enhancing mood regulation.
• 5‑HT1B partial agonist – modulates presynaptic feedback to reduce serotonin release in high‑tone circuits.
• 5‑HT3 antagonist – diminishes nausea and improves tolerability.
• 5‑HT7 antagonist – contributes to rapid improvement of executive function and circadian rhythm.
• 5‑HT1D blocker/5‑HT1E antagonist – further influences serotonin reuptake dynamics.
• Serotonin transporter (SERT) inhibition – increases extracellular serotonin concentrations across the brain.

The combination of reuptake inhibition with selective receptor modulation results in distinct therapeutic and tolerability profiles relative to classical SSRIs.

Pharmacokinetics

• Absorption: Rapid oral absorption with peak plasma concentrations (C_max) at ~2–3 h post‑dose.
• Bioavailability: Approximately 50 %—unaffected by food.
• Metabolism: Predominantly via CYP2D6 and CYP2C9; glucuronidation contributes minimally.
• Half‑life: ~66 h, permitting once‑daily dosing.
• Elimination: Excreted mainly as unchanged drug (<8 %) and metabolites (~10 %) via kidney; small biliary component.

*Clinical note:* Poor CYP2D6 metabolizers may exhibit higher serum levels; dose adjustments may be needed (see Dosing and Administration).

Indications

• Major Depressive Disorder (Adults) – efficacy demonstrated in moderate to severe MDD.
• Adjunctive therapy – may be combined with psychotherapy or other pharmacologic agents (e.g., antidepressant augmentation).

Contraindications

• Contraindicated in patients with known hypersensitivity to vortioxetine or any component of the formulation.
• Warnings:
• *Serotonin syndrome* – risk increases when combined with other serotonergic drugs (MAOIs, triptans, linezolid, tramadol).
• *Suicidal ideation* – monitor patients under 25 years per boxed warning.
• *QT interval prolongation* – minimal effect; caution with agents that prolong QT.
• *Pregnancy* – category C; use only if benefits outweigh risks.

Avoid initiation within 14 days of discontinuing MAOIs; allow 14 days after starting MAOIs.

Dosing

• Route: Oral tablet.
• Take with or without food – no food restriction.
• Administration: Once daily; consistency in timing improves adherence.

*Tip:* Reduce dose to 10 mg for poor CYP2D6 metabolizers or when significant drug interactions are anticipated.

Adverse Effects

• Common (≥10 %)
• Nausea
• Diarrhea
• Somnolence
• Dry mouth
• Headache
• Sexual dysfunction (lower incidence vs. SSRIs)
• Serious
• Serotonin syndrome (visual, autonomic, neuromuscular signs)
• Suicidal ideation/behavior (especially in adolescents, young adults)
• Severe GI distress leading to dehydration
• QT prolongation (rare)

Patients should report any confusion, agitation, tremor, or visual changes promptly.

Monitoring

• Baseline: Complete medical history, mental health evaluation, pregnancy test (if applicable).
• During therapy:
• Monitor mood changes and suicidality at each visit (Week 2, 4, 8, 12).
• Assess GI tolerance and weight.
• Periodic ECG if QT‑prolonging agents are used concurrently.
• Renal function is not routinely required but should be re‑checked in chronic kidney disease.

Patients on CYP2D6 inhibitors (paroxetine, fluoxetine) should have dose reviewed within 2 weeks of initiation.

Clinical Pearls

• Rapid onset – Dayvigo may improve mood and cognitive symptoms within the first week, facilitating early functional recovery.
• Low sexual adverse profile – Compared to SSRIs, vortioxetine frequently yields fewer sexual complaints, enhancing adherence in sensitive populations.
• Cognitive boost – The 5‑HT7 antagonism and 5‑HT1A agonism enhance executive function and memory, valuable in patients reporting “brain fog.”
• Minimal sedation – Low affinity for α1‑adrenergic receptors means Dayvigo does not usually cause daytime drowsiness, unlike older antidepressants.
• Drug interactions – Strong CYP2D6 inhibitors double trough concentrations; strong inducers reduce efficacy. Consider routine dose check after any new medication initiation.
• Pediatric‑use – Not approved; use only in clinical trials.
• Pregnancy – Category C; provide counseling and consider alternative agents if risk of fetal exposure outweighs benefit.

By integrating these unique pharmacologic features, Dayvigo offers a valuable alternative for clinicians seeking efficacy, tolerability, and cognitive benefit in the treatment of MDD.