Does flecainide cause reduced libido?

Flecainide and Sexual Function

Flecainide does not commonly cause reduced libido as a reported side effect, though sexual dysfunction is not prominently listed in its adverse effect profile. 1

Evidence on Flecainide and Sexual Side Effects

The FDA drug label for flecainide lists numerous adverse effects but does not specifically mention reduced libido or sexual dysfunction among its common side effects 1. The most frequently reported non-cardiac adverse effects of flecainide include:

• Dizziness (18.9%)
• Visual disturbances (15.9%)
• Dyspnea (10.3%)
• Headache (9.6%)
• Nausea (8.9%)
• Fatigue (7.7%)

While the FDA label does mention "decreased libido" as a psychiatric adverse effect, it occurs in less than 1% of patients 1, making it a rare side effect rather than a common concern.

Comparison with Other Cardiac Medications

In contrast to flecainide, other cardiovascular medications are more commonly associated with sexual dysfunction:

• Beta-blockers are known to cause sexual disturbances including reduced libido 2
• The 2015 ESC guidelines specifically list "sexual disturbances" as a common adverse effect of beta-blockers 2

Mechanisms of Drug-Induced Sexual Dysfunction

Sexual dysfunction from medications typically occurs through several mechanisms:

• Hormonal effects (altering testosterone or estrogen levels)
• Vascular effects (reducing blood flow)
• Neurological effects (altering neurotransmitters involved in sexual function)
• Psychological effects (sedation, mood changes)

Flecainide, as a Class I antiarrhythmic that works primarily by blocking sodium channels, does not significantly affect these pathways at therapeutic doses 3.

Clinical Implications and Management

If a patient reports reduced libido while taking flecainide:

1. Consider other causes of sexual dysfunction:

   • Other medications (especially beta-blockers, antidepressants)
   • Underlying cardiovascular disease
   • Psychological factors (anxiety, depression)
   • Hormonal imbalances

2. Evaluate for potential drug interactions that might be contributing to the symptom

3. If flecainide is strongly suspected as the cause:

   • Consider alternative antiarrhythmic options if appropriate for the patient's condition
   • Do not abruptly discontinue flecainide without medical supervision

Important Considerations

• Sexual dysfunction is multifactorial and may be related to underlying cardiovascular disease rather than medication
• Patients with chronic illnesses often experience decreased libido independent of medication effects 2
• When evaluating medication side effects, consider the baseline prevalence of sexual dysfunction in the general population

Conclusion

Based on the available evidence, flecainide is not commonly associated with reduced libido. If a patient experiences sexual dysfunction while taking flecainide, other causes should be investigated before attributing the symptom to this medication.