Sexual Side Effects of Atomoxetine
Atomoxetine causes sexual side effects primarily in adult males, with erectile dysfunction (8.0%), decreased libido (4.6%), ejaculation disorder (2.8%), and urinary hesitation (6.9%) being the most common, while sexual side effects are minimal in females and adolescent males. 1, 2
Adult Male Population
The sexual side effects in adult males treated with atomoxetine are notably more frequent compared to placebo:
- Erectile dysfunction occurs in 8.0% of atomoxetine-treated adult males versus 1.9% with placebo 2
- Decreased libido affects 4.6% versus 3.0% with placebo 2
- Ejaculation disorder occurs in 2.8% versus 1.1% with placebo 2
- Urinary hesitation affects 6.9% versus 2.4% with placebo 2
- Decreased urine flow occurs in 2.5% versus 0.6% with placebo 2
- Dysuria affects 3.7% versus 1.5% with placebo 2
The FDA label confirms that sexual side effects and problems passing urine are common adverse effects in adults 1.
Time Course and Resolution
Sexual side effects follow a predictable temporal pattern in adult males:
- Onset timing: Erectile and ejaculation issues typically emerge during the second and third week of dosing, while genitourinary symptoms appear within the first 2 weeks 2
- Resolution timing: The median time to resolution ranges from 3-8 weeks after event onset, depending on the specific event 2
- Severity: Most sexual and genitourinary adverse events are not considered severe, though they show numerically higher discontinuation rates compared to placebo 2
Female and Adolescent Populations
The sexual side effect profile in females and adolescent males is clinically similar to placebo 2:
- Female patients show no meaningful difference in sexual side effects between atomoxetine and placebo 2
- Adolescent male patients (ages 13-17) demonstrate sexual side effect rates comparable to placebo 2
Rare Sexual Side Effects
- Priapism (erections lasting >4 hours) has occurred rarely during atomoxetine treatment and requires immediate medical evaluation due to potential for lasting damage 1
- Spontaneous ejaculation has been reported in at least one adolescent case, beginning on the third day of treatment and resolving with discontinuation 3
CYP2D6 Metabolizer Status Impact
Poor CYP2D6 metabolizers experience significantly higher rates of sexual side effects:
- Erectile dysfunction occurs in 21% of poor metabolizers versus 9% in extensive metabolizers 4
- Dry mouth affects 35% versus 17% in extensive metabolizers 4
- Approximately 7% of Caucasians and 2% of African Americans are poor CYP2D6 metabolizers, resulting in 10-fold higher drug exposure 5, 4
Clinical Management Considerations
When sexual side effects occur with atomoxetine:
- Monitor for onset within the first 2-3 weeks of treatment, particularly in adult males 2
- Recognize that resolution may take 3-8 weeks after symptom onset 2
- Consider CYP2D6 metabolizer status if sexual side effects are severe or intolerable 4
- Be aware that sexual side effects are likely underreported in clinical trials 2
- Educate patients that most events are mild to moderate in severity 2
Important Caveats
- Sexual dysfunction data from clinical trials likely represents underreporting, as patients may be reluctant to disclose these symptoms 2
- The overall rate of sexual dysfunction in atomoxetine-treated patients is approximately 2% across all populations 6
- Concomitant use of CYP2D6 inhibitors (such as certain SSRIs) can elevate atomoxetine levels and potentially increase sexual side effects 4