Fluvoxamine is a selective serotonin reuptake inhibitor (SSRI) antidepressant licensed in the UK for treating depression and obsessive-compulsive disorder. Whilst effective for mental health conditions, fluvoxamine can cause sexual side effects, including erectile dysfunction, which affects a significant proportion of men taking SSRIs. Understanding whether fluvoxamine causes erectile dysfunction, why this occurs, and how it can be managed is essential for maintaining both mental health treatment and quality of life. This article explores the relationship between fluvoxamine and erectile function, the underlying mechanisms, and practical management strategies available through your GP.

What Is Fluvoxamine and How Does It Work?

Fluvoxamine is a selective serotonin reuptake inhibitor (SSRI) antidepressant licensed in the UK for the treatment of depression and obsessive-compulsive disorder (OCD). It is marketed under the brand name Faverin, though generic versions are also available. As with other SSRIs, fluvoxamine works by increasing the availability of serotonin in the brain, a neurotransmitter that plays a crucial role in regulating mood, anxiety, and emotional wellbeing.

The mechanism of action involves blocking the reuptake of serotonin at the presynaptic neurone, thereby prolonging its activity in the synaptic cleft. This enhanced serotonergic transmission is thought to alleviate symptoms of depression and anxiety over time, typically requiring several weeks of treatment before therapeutic benefits become apparent. Fluvoxamine is generally well-tolerated, but like all medications, it can cause side effects.

Common side effects of fluvoxamine include:

• Nausea and gastrointestinal disturbance

• Headache and dizziness

• Drowsiness or insomnia

• Sweating

• Sexual dysfunction, including erectile difficulties

Sexual side effects are recognised as one of the more troublesome adverse effects of SSRI therapy, affecting a significant proportion of patients. These effects can include reduced libido, delayed ejaculation, anorgasmia, and erectile dysfunction. In some cases, sexual dysfunction may persist after stopping treatment, as highlighted in MHRA safety updates. Understanding the relationship between fluvoxamine and sexual function is important for both patients and healthcare professionals, as these side effects can significantly impact quality of life and treatment adherence. If you are experiencing sexual difficulties whilst taking fluvoxamine, it is essential to discuss this openly with your GP rather than discontinuing treatment abruptly, as sudden cessation can lead to withdrawal symptoms.

Why Do SSRIs Like Fluvoxamine Affect Sexual Function?

Sexual dysfunction is a well-documented side effect of SSRI antidepressants, with research suggesting that a substantial proportion of patients may experience some form of sexual difficulty during treatment. The reported rates vary widely depending on study methodology, patient populations, and whether side effects are spontaneously reported or systematically assessed. Erectile dysfunction specifically affects a significant number of men taking SSRIs, though precise figures for fluvoxamine alone are difficult to establish.

The mechanism by which fluvoxamine and other SSRIs cause sexual side effects is likely multifaceted, though several hypotheses exist. Elevated serotonin levels may inhibit sexual function through several pathways. Serotonin is thought to have an inhibitory effect on dopamine and noradrenaline pathways, both of which are important for sexual arousal and erectile function. Some research suggests that increased serotonergic activity might stimulate prolactin release from the pituitary gland, and elevated prolactin levels are associated with reduced libido and erectile difficulties.

There are also hypotheses that SSRIs may affect nitric oxide pathways, which are crucial for achieving and maintaining an erection. Nitric oxide is a key mediator of smooth muscle relaxation in the corpus cavernosum of the penis, allowing increased blood flow necessary for erection. The exact mechanisms remain under investigation.

It is important to note that depression and anxiety themselves can significantly impair sexual function, making it sometimes difficult to distinguish between symptoms of the underlying condition and medication side effects. Factors that may contribute to erectile dysfunction include:

• The underlying mental health condition

• Medication effects on neurotransmitter systems

• Psychological factors such as performance anxiety

• Concurrent physical health conditions (cardiovascular disease, diabetes)

• Other medications (beta-blockers, thiazide diuretics, antipsychotics)

• Lifestyle factors (alcohol, smoking, recreational drugs)

• Hormonal imbalances (low testosterone, thyroid disorders)

A thorough assessment by your GP can help identify the most likely cause and guide appropriate management.

Managing Erectile Dysfunction While Taking Fluvoxamine

If you are experiencing erectile dysfunction whilst taking fluvoxamine, there are several management strategies that may be considered in consultation with your GP. It is crucial never to stop or alter your medication without medical supervision, as this can lead to relapse of your mental health condition or cause discontinuation symptoms.

One approach is to allow more time for adjustment, as some sexual side effects may diminish after the first few weeks or months of treatment as your body adapts to the medication. However, if symptoms persist or are significantly affecting your quality of life, your GP may discuss alternative strategies.

Potential management options include:

• Dose adjustment: In some cases, reducing the dose of fluvoxamine may alleviate sexual side effects whilst maintaining therapeutic benefit for your mental health condition. This must be done gradually and under medical supervision.

• Medication switching: Your doctor may consider switching to an alternative antidepressant with a lower risk of sexual side effects. Options might include mirtazapine, moclobemide, or vortioxetine (which NICE has approved for treating major depressive episodes), though the choice depends on your individual circumstances and the condition being treated.

• Adjunctive treatments: Phosphodiesterase-5 (PDE-5) inhibitors such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra) may be prescribed to help manage erectile dysfunction. These medications require careful consideration:

• They are absolutely contraindicated in patients taking nitrates or nicorandil due to risk of severe hypotension
• Caution is needed if you take alpha-blockers
• Your GP should assess cardiovascular risk before prescribing

• Lower starting doses may be appropriate with fluvoxamine, as it inhibits certain liver enzymes (CYP1A2, CYP3A4, CYP2C19) that metabolise these medications

• Psychological support: Cognitive behavioural therapy (CBT) or psychosexual counselling may help address any psychological factors contributing to sexual difficulties.

Your GP may also investigate other potential causes of erectile dysfunction, including cardiovascular disease, diabetes, hormonal imbalances, or other medications. This might involve checking your blood pressure, lipid profile, blood glucose/HbA1c, and morning testosterone levels. NICE guidance emphasises the importance of a holistic approach to managing sexual dysfunction, addressing both physical and psychological factors.

If treatments are unsuccessful or there are concerns about underlying causes, your GP may refer you to a specialist urology or sexual health service.

When to Speak to Your GP About Sexual Side Effects

Sexual side effects from antidepressants are common but often underreported, as many patients feel embarrassed or uncomfortable discussing these issues. However, open communication with your GP is essential for optimising your treatment and maintaining your quality of life. You should arrange to speak with your doctor if:

• You develop new erectile difficulties after starting fluvoxamine

• Sexual side effects are causing significant distress or affecting your relationship

• You are considering stopping your medication due to sexual problems

• Sexual dysfunction is not improving after several months of treatment

• You have concerns about other potential causes of erectile difficulties

Your GP is accustomed to discussing sexual health matters and will approach the conversation professionally and confidentially. They will likely ask about the timing of symptoms, their severity, and their impact on your life. They may also enquire about other aspects of your health, including cardiovascular risk factors, as erectile dysfunction can sometimes be an early indicator of underlying health conditions such as diabetes or heart disease.

It is particularly important to seek medical advice rather than discontinuing fluvoxamine abruptly. Sudden cessation of SSRIs can lead to discontinuation syndrome, characterised by symptoms such as dizziness, nausea, headache, anxiety, and flu-like symptoms. If a change in medication is appropriate, your GP will create a plan to taper your current medication gradually whilst potentially introducing an alternative.

When to seek urgent medical attention:

Whilst erectile dysfunction itself is not a medical emergency, you should attend A&E immediately if you experience a painful erection lasting more than four hours (priapism), particularly if you are taking additional medications for erectile dysfunction alongside fluvoxamine. This is a medical emergency requiring immediate treatment.

If you experience thoughts of self-harm or significant worsening of your mental health, contact your local NHS mental health crisis team, call NHS 111, or in an emergency, call 999.

Remember that effective treatment for depression and anxiety is essential for your overall wellbeing, and sexual side effects, whilst troublesome, can often be successfully managed without compromising your mental health treatment. Your GP can work with you to find the most appropriate balance between managing your mental health condition and maintaining your sexual function and quality of life.

If you believe you have experienced a side effect from fluvoxamine, you can report it through the MHRA Yellow Card Scheme, which helps monitor medication safety.

Frequently Asked Questions