What are the indications, dosing, side effects, and drug interactions of vortioxetine?

Vortioxetine: Indications, Dosing, Side Effects, and Drug Interactions

Indication

Vortioxetine is FDA-approved for the treatment of major depressive disorder (MDD) in adults. 1 It is a multimodal antidepressant that enhances serotonergic activity through serotonin reuptake inhibition and direct modulation of multiple serotonin receptor subtypes (5-HT3 antagonism, 5-HT1A agonism, among others). 1

Recent evidence demonstrates vortioxetine's effectiveness when switching from SSRIs/SNRIs in patients experiencing inadequate response, particularly for emotional blunting—a common residual symptom of depression. 2

Dosing

Start vortioxetine at 10 mg once daily, then increase to 20 mg daily as tolerated. 1

Standard Dosing Algorithm:

• Initial dose: 10 mg orally once daily (without regard to meals) 1
• Target dose: 20 mg once daily as tolerated 1
• Lower dose option: 5 mg daily for patients who cannot tolerate higher doses 1
• Time to steady state: Approximately 2 weeks 1
• Half-life: 66 hours 1

Dose Adjustments:

CYP2D6 Poor Metabolizers:

• Maximum dose: 10 mg daily (these patients have approximately twice the plasma concentration of extensive metabolizers) 1

With Strong CYP2D6 Inhibitors (e.g., bupropion):

• Reduce vortioxetine dose by half 1

With Strong CYP Inducers (e.g., rifampin):

• Consider dose increase when coadministered >14 days
• Maximum: 3 times the original dose 1

Special Populations:

• No dose adjustment needed for age, gender, ethnicity, renal impairment, or hepatic impairment 1

Discontinuation:

• Can be stopped abruptly 1
• For doses of 15-20 mg daily: taper to 10 mg daily for 1 week before full discontinuation if possible 1

Side Effects

The most common adverse effects are nausea (20.9% in real-world data), constipation, and vomiting. 1, 2

Common Adverse Effects (≥5% and twice placebo rate):

• Nausea 1
• Constipation 1
• Vomiting 1

Additional Reported Adverse Effects:

• Diarrhea 3
• Dry mouth 3
• Headache 3
• Dizziness 3

Serious Warnings (FDA Boxed Warning):

Suicidal Thoughts and Behaviors:

• Increased risk in pediatric and young adult patients 1
• Close monitoring required for worsening and emergence of suicidal thoughts 1
• Not approved for pediatric use 1

Other Important Safety Concerns:

Serotonin Syndrome:

• Risk increases with concomitant serotonergic agents 1
• Discontinue vortioxetine and all serotonergic agents if occurs 1

Bleeding Risk:

• Increased risk with concomitant aspirin, NSAIDs, antiplatelet drugs, warfarin, or other anticoagulants 1

Activation of Mania/Hypomania:

• Screen patients for bipolar disorder before initiating 1

Angle-Closure Glaucoma:

• Can occur in patients with untreated anatomically narrow angles 1

Hyponatremia:

• Associated with SIADH 1

Sexual Dysfunction:

• May cause symptoms of sexual dysfunction 1

Tolerability Profile:

In real-world European data, adverse events were reported by 52.2% of patients, with most being mild to moderate. 4 The proportion of patients experiencing serious events (suicidal events, seizures, severe renal/hepatic events) was ≤1%. 4

Drug Interactions

Vortioxetine has a favorable drug interaction profile with minimal effects on CYP enzymes, but requires dose adjustment with strong CYP2D6 inhibitors and broad CYP inducers. 5

Contraindicated Combinations:

MAOIs:

• Do not use MAOIs intended to treat psychiatric disorders with vortioxetine 1
• Do not use vortioxetine within 14 days of stopping an MAOI 1
• Do not start vortioxetine within 21 days of stopping vortioxetine before starting an MAOI 1
• Do not use with linezolid or IV methylene blue 1

Major Interactions Requiring Dose Adjustment:

Strong CYP2D6 Inhibitors (e.g., bupropion, fluoxetine, paroxetine, quinidine):

• Reduce vortioxetine dose by 50% 1, 6

Broad CYP Inducers (e.g., rifampin, carbamazepine, phenytoin):

• Consider increasing vortioxetine dose up to 3 times the original dose if coadministered >14 days 1

Serotonergic Agents (Risk of Serotonin Syndrome):

• Triptans 7
• SSRIs/SNRIs 7
• Tricyclic antidepressants 7
• Tramadol 7
• Tryptophan 7
• St. John's wort 7
• Lithium 7

No Clinically Significant Interactions:

Vortioxetine does NOT significantly affect:

• Warfarin (no effect on INR or pharmacokinetics) 8
• Aspirin (no effect on platelet aggregation or pharmacokinetics) 8
• Diazepam (no pharmacokinetic or pharmacodynamic interactions) 9
• Lithium (no effect on lithium levels) 9
• Ethanol (no effect on psychomotor performance or pharmacokinetics) 9
• Bupropion, warfarin, diazepam substrates 1

Vortioxetine is NOT significantly affected by:

• Most CYP substrates (does not inhibit CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4/5) 1
• Does not induce CYP enzymes 1

Metabolism:

Vortioxetine is extensively metabolized via CYP2D6 (primary), CYP3A4/5, CYP2C19, CYP2C9, CYP2A6, CYP2C8, and CYP2B6, followed by glucuronidation. 1 The major metabolite is pharmacologically inactive. 1

Clinical Pearls:

• Vortioxetine has minimal drug-drug interaction potential compared to older antidepressants 5
• No dose adjustment needed with most commonly prescribed medications 6
• The multimodal mechanism (serotonin reuptake inhibition plus receptor modulation) may provide benefits for emotional blunting and cognitive symptoms beyond traditional SSRIs 2