Paroxetine (Seroxat) is a selective serotonin reuptake inhibitor (SSRI) antidepressant widely prescribed for depression, anxiety disorders, and obsessive-compulsive disorder. Sexual dysfunction, including erectile dysfunction, is a well-documented adverse effect of paroxetine, occurring more frequently than with some other antidepressants. According to the Summary of Product Characteristics, impotence affects up to 1 in 10 men taking this medication. Understanding the link between paroxetine and erectile difficulties, alongside available management strategies, is essential for balancing mental health treatment with sexual wellbeing. This article examines the evidence, mechanisms, and practical approaches to managing this common side effect.

Does Paroxetine Cause Erectile Dysfunction?

Paroxetine (brand name Seroxat in the UK, known as Paxil in the US) is a selective serotonin reuptake inhibitor (SSRI) antidepressant commonly prescribed for depression, anxiety disorders, and obsessive-compulsive disorder. Sexual dysfunction, including erectile dysfunction (ED), is a well-documented adverse effect of paroxetine and is reported more frequently with this medication than with some other antidepressants.

Clinical evidence suggests that a significant proportion of patients taking SSRIs experience some form of sexual side effect, with paroxetine showing particularly high rates. According to the Summary of Product Characteristics (SmPC), ejaculation disorder is classified as a 'very common' side effect (affecting more than 1 in 10 people), while impotence is listed as 'common' (affecting up to 1 in 10 people). Erectile dysfunction specifically affects many men taking paroxetine, though exact prevalence varies between studies. The proposed mechanism involves increased serotonin levels in the central nervous system, which may inhibit sexual arousal pathways and potentially affect nitric oxide signalling—a key mediator of penile erection.

The onset of erectile dysfunction typically occurs within the first few weeks of treatment, though it may develop later. Symptoms can include difficulty achieving or maintaining an erection sufficient for sexual intercourse, reduced rigidity, or delayed erectile response. It is important to note that depression and anxiety themselves can cause sexual dysfunction, making it sometimes challenging to distinguish medication-related effects from underlying condition symptoms.

Dose-dependent effects have been observed, with higher doses of paroxetine generally associated with increased risk of sexual side effects. However, even at lower therapeutic doses, erectile dysfunction remains a common concern. The MHRA recognises sexual dysfunction as a known adverse reaction to paroxetine, and patient information leaflets routinely include this warning. Importantly, the MHRA has also issued a safety alert about the potential for persistent sexual dysfunction that can continue even after stopping SSRI treatment in some cases.

If you are experiencing erectile difficulties after starting paroxetine, it is essential to discuss this with your GP rather than discontinuing treatment abruptly, as sudden cessation can lead to withdrawal symptoms.

Managing Erectile Dysfunction While Taking Paroxetine

If you develop erectile dysfunction while taking paroxetine, several management strategies may help whilst maintaining effective treatment for your mental health condition. Never stop taking paroxetine suddenly without medical supervision, as this can cause discontinuation syndrome with symptoms including dizziness, sensory disturbances, anxiety, and flu-like symptoms.

Initial management approaches include:

• Dose adjustment: Your GP may consider reducing your paroxetine dose to the minimum effective level, which can sometimes alleviate sexual side effects whilst maintaining therapeutic benefit for depression or anxiety

• Timing modification: Taking your medication at a different time of day (such as after sexual activity) may help some patients, though there is limited evidence for this approach

• Drug holidays: Brief planned interruptions in medication before anticipated sexual activity have been studied, but this approach carries significant risks of symptom relapse and discontinuation effects and is generally not recommended for paroxetine due to its relatively short half-life

Pharmacological interventions may be considered under appropriate guidance. Phosphodiesterase-5 (PDE-5) inhibitors such as sildenafil, tadalafil, or vardenafil can be effective for SSRI-induced erectile dysfunction. These medications work by enhancing nitric oxide effects in penile tissue. Most PDE-5 inhibitors require a prescription, though sildenafil 50mg is available from pharmacists without a prescription following an assessment. Important contraindications include nitrate medications, riociguat, recent stroke or heart attack, severe cardiovascular disease, and certain eye conditions. PDE-5 inhibitors also require caution when used with alpha-blockers. Note that these medications specifically address erectile function and will not help with reduced libido or orgasmic problems.

Non-pharmacological approaches include psychosexual counselling, which can address psychological factors contributing to sexual difficulties, and lifestyle modifications such as regular exercise, smoking cessation, and moderating alcohol intake. Some patients find that sexual side effects diminish over time with continued treatment, though this is not universal. Your GP can refer you to specialist sexual health services or psychiatry if first-line management strategies prove insufficient.

Alternative Antidepressants With Lower Sexual Side Effects

If erectile dysfunction persists despite management strategies, switching to an alternative antidepressant with a lower propensity for sexual side effects may be appropriate. This decision should be made collaboratively with your GP or psychiatrist, considering your individual response to treatment, severity of depression or anxiety, and previous medication history.

Antidepressants generally associated with lower rates of sexual dysfunction include:

• Mirtazapine: A noradrenergic and specific serotonergic antidepressant (NaSSA) that works through different mechanisms than SSRIs. Sexual side effects appear to occur less frequently than with SSRIs like paroxetine. However, mirtazapine commonly causes sedation and weight gain, which may be problematic for some patients

• Bupropion: A noradrenaline and dopamine reuptake inhibitor that is not licensed for depression in the UK (it is licensed as Zyban for smoking cessation). Any use for depression would be off-label and typically initiated by specialists. It has minimal sexual side effects and may even improve sexual function in some patients. Bupropion is contraindicated in patients with seizure disorders or eating disorders

• Agomelatine: A melatonergic antidepressant with a unique mechanism of action. Sexual dysfunction rates are comparable to placebo in clinical trials. However, it requires monitoring of liver function (at baseline and at weeks 3, 6, 12 and 24) and is contraindicated in patients with hepatic impairment. It is typically reserved for cases where other antidepressants have been ineffective

• Vortioxetine: A newer antidepressant with multimodal activity. Clinical trials suggest lower rates of sexual dysfunction compared to some SSRIs, though sexual side effects can still occur. It is more expensive and may not be first-line in all NHS areas

Switching antidepressants requires careful planning. Paroxetine has a relatively short half-life and high risk of discontinuation symptoms, so cross-tapering (gradually reducing paroxetine whilst introducing the new medication) is usually necessary. NICE guidance recommends that switching should be undertaken with appropriate monitoring, particularly during the transition period when patients may be vulnerable to symptom relapse. Your GP will develop an individualised switching regimen based on your specific circumstances, and you should be reviewed regularly during this process to assess both mental health symptoms and side effect profile.

When to Speak to Your GP About Paroxetine and Sexual Health

Open communication with your GP about sexual side effects is essential for optimising both your mental and sexual health. Many patients feel embarrassed discussing erectile dysfunction, but it is a common and recognised adverse effect that healthcare professionals are accustomed to addressing. Many people experiencing sexual side effects do not report them spontaneously, leading to unnecessary distress and sometimes non-adherence to treatment.

You should contact your GP if:

• Erectile dysfunction develops or worsens after starting paroxetine or increasing the dose

• Sexual side effects are causing significant distress or relationship difficulties

• You are considering stopping your medication due to sexual problems

• Erectile dysfunction is persistent and causing ongoing distress

• You experience other concerning symptoms alongside erectile dysfunction, such as loss of libido, delayed ejaculation, or anorgasmia

Seek urgent medical attention if you develop priapism (a persistent, painful erection lasting more than 4 hours), though this is extremely rare with SSRIs. Additionally, if you experience sudden onset of severe erectile dysfunction alongside chest pain, breathlessness, or other cardiovascular symptoms, this requires immediate assessment as it may indicate an unrelated serious condition.

Before your appointment, it can be helpful to document the timeline of when sexual difficulties began in relation to starting paroxetine, the severity of symptoms, and their impact on your quality of life. Your GP will need to assess whether erectile dysfunction is medication-related or potentially due to other factors. This may involve cardiovascular risk assessment, blood pressure measurement, and in some cases blood tests (such as HbA1c, lipids, and morning testosterone if there are features suggesting hypogonadism).

Remember that effective treatment for depression and anxiety is crucial for overall wellbeing, and sexual health is an important component of quality of life. Your GP can work with you to find a solution that addresses both your mental health needs and sexual function, whether through management strategies, medication adjustment, or switching to an alternative antidepressant. Patient-centred care involves balancing therapeutic efficacy with tolerability, and sexual side effects should never be dismissed as an inevitable consequence of treatment.

If you experience any suspected adverse effects from medication, you can report them through the MHRA Yellow Card Scheme, which helps monitor medication safety.

Frequently Asked Questions