Sexual Side Effects of Strattera and Prozac Combination
Critical Drug Interaction Warning
When taking Strattera (atomoxetine) and Prozac (fluoxetine) together, you face dramatically amplified sexual dysfunction risk because Prozac increases Strattera blood levels by 6- to 8-fold, converting even normal metabolizers into poor metabolizers with significantly higher rates of erectile dysfunction (21% vs 9%), decreased libido (3% vs 1%), and ejaculation disorders (6% vs 2%). 1
Mechanism of Amplified Risk
The combination creates a pharmacokinetic interaction that substantially worsens sexual side effects:
- Prozac inhibits CYP2D6, the enzyme that metabolizes Strattera, causing Strattera concentrations to increase approximately 6- to 8-fold at steady state 1
- This converts you into a "poor metabolizer" phenotype, even if you normally metabolize drugs efficiently 1
- Poor metabolizers experience 2-3 times higher rates of sexual dysfunction compared to normal metabolizers across all sexual domains 1
Specific Sexual Side Effects to Expect
From Strattera (Amplified by Prozac):
- Erectile dysfunction: 21% in poor metabolizers vs 9% in normal metabolizers 1
- Decreased libido: 3% overall incidence 1
- Ejaculation delay/disorder: 6% in poor metabolizers vs 2% in normal metabolizers 1
- Urinary hesitation: 6% (can indirectly affect sexual function) 1
- Orgasm abnormalities: reported in post-marketing surveillance 1
From Prozac (Fluoxetine):
- Moderate-high sexual dysfunction rates overall, though lower than paroxetine 2
- Delayed or absent orgasm in both sexes 2
- Decreased libido 2
- Erectile dysfunction in males 2
- Sexual side effects are strongly dose-related with SSRIs 2
Critical Clinical Caveat
Sexual dysfunction from both medications is vastly underreported in clinical trials because patients and physicians are reluctant to discuss these issues, meaning actual rates are likely substantially higher than the published figures 1, 2
Management Algorithm
Step 1: Assess Current Necessity
- Determine if both medications are absolutely required or if one could be discontinued 2
- Consider whether depression/ADHD symptoms justify the sexual dysfunction burden 2
Step 2: If Both Medications Required
- Reduce Strattera dose to the minimum effective level, as the 6-8 fold increase from Prozac may allow lower dosing 1
- Monitor for sexual side effects within 1-2 weeks of starting combination, as most emerge early 2
Step 3: If Sexual Dysfunction Occurs
Primary strategy: Switch Prozac to bupropion if depression treatment allows, as bupropion has only 8-10% sexual dysfunction rates compared to SSRIs 2, 3
Important contraindications for bupropion:
Step 4: Augmentation for Erectile Dysfunction
- Add PDE5 inhibitor (sildenafil or tadalafil) if erectile dysfunction is the primary complaint 3
- This addresses erectile function but not libido or orgasm issues 3
Step 5: Alternative Antidepressant Options
If bupropion is contraindicated:
- Mirtazapine 7.5-30 mg at bedtime has lower sexual dysfunction rates than SSRIs, though causes sedation and weight gain 4
- Escitalopram or citalopram have intermediate sexual dysfunction rates, lower than fluoxetine 2
Monitoring Requirements
- Inquire specifically about sexual function at every visit, as patients rarely volunteer this information 1
- Ask about all domains: desire/libido, arousal, erectile function, orgasm/ejaculation, and overall satisfaction 1
- Reassess within 6-8 weeks if management strategy implemented 2
Important Safety Consideration
Never abruptly stop Prozac if switching medications, as this can precipitate SSRI withdrawal syndrome; taper gradually over 10-14 days 2, 4