Are Vilazodone (vortioxetine) 40mg and Abilify (aripiprazole) 2mg causing the patient's symptoms of dizziness, lightheadedness, and sexual dysfunction?

Which Medication is Causing Dizziness, Lightheadedness, and Sexual Dysfunction?

Both vilazodone and aripiprazole can contribute to these symptoms, but vilazodone is the more likely primary culprit for sexual dysfunction, while both medications can cause dizziness and lightheadedness. 1

Sexual Dysfunction Attribution

Vilazodone (40mg) is the predominant cause of sexual dysfunction in this regimen. Despite being marketed as having a more favorable sexual side effect profile due to its 5-HT1A partial agonist activity, vilazodone still causes sexual dysfunction as an SSRI-class medication 1, 2:

• The FDA label explicitly warns that vilazodone may cause ejaculatory delay or failure, decreased libido, and erectile dysfunction in males 1
• Clinical trial data showed 8.0% of vilazodone-treated patients reported sexual function-related adverse events versus 0.9% on placebo 2
• While vilazodone may have less sexual dysfunction than traditional SSRIs like paroxetine (70.7% incidence) or citalopram, it still causes these effects more than placebo 3, 4

Aripiprazole at 2mg is less likely to be the primary cause of sexual dysfunction at this low dose, though antipsychotics can contribute to sexual problems through dopamine antagonism.

Dizziness and Lightheadedness Attribution

Both medications contribute to orthostatic symptoms, making this a shared adverse effect:

Vilazodone's Contribution:

• The FDA label lists dizziness as part of the discontinuation syndrome and general adverse effect profile 1
• Dizziness was reported as a common side effect in clinical trials, particularly with dapoxetine (another SSRI), suggesting this is a class effect 5

Aripiprazole's Contribution:

• Alpha-1 adrenergic blockade from aripiprazole can cause orthostatic hypotension and dizziness, even at low doses 5
• This effect is well-documented with antipsychotic medications through their alpha-adrenergic antagonism 5

Clinical Decision Algorithm

Step 1: Address Sexual Dysfunction First

• Consider switching vilazodone to bupropion (150-400 mg/day), which has significantly lower sexual dysfunction rates (8-10%) compared to all SSRIs 3, 6
• Bupropion should not be used if the patient has seizure history, eating disorders, or significant agitation 3, 7
• Alternative: Add a PDE5 inhibitor (sildenafil or tadalafil) if switching antidepressants is not feasible 6

Step 2: Manage Orthostatic Symptoms

• If dizziness persists after addressing vilazodone, consider reducing aripiprazole from 2mg to 1mg or discontinuing if clinically appropriate
• Counsel on rising slowly from sitting/lying positions and adequate hydration 5
• Monitor blood pressure in sitting and standing positions to confirm orthostatic hypotension

Step 3: Gradual Medication Changes

• When discontinuing vilazodone, taper gradually to avoid discontinuation syndrome (which includes dizziness as a prominent symptom) 1
• Cross-taper when switching to bupropion over 1-2 weeks

Important Clinical Caveats

• Screen for bipolar disorder before switching to bupropion, as it may precipitate mania 1
• Sexual dysfunction is vastly underreported in clinical trials, so actual rates are likely higher than published figures 3
• Timing matters: Most sexual adverse effects emerge within the first few weeks of SSRI treatment 3
• Inquire specifically about sexual function, as patients rarely volunteer this information spontaneously 1
• Consider cardiovascular evaluation if orthostatic symptoms are severe, as dizziness can indicate more serious cardiovascular issues 6