Fildena and the Food Pipe: What Sildenafil Does to Esophageal Motility

Clinical Vignette: When Acid Reflux Meets Erectile Dysfunction Treatment

Mr. K., a 54-year-old accountant with a history of well-controlled hypertension and chronic gastroesophageal reflux disease (GERD), recently returned to his primary care provider with a new concern. He had been prescribed Fildena 100 mg (a brand of sildenafil citrate) for mild erectile dysfunction. The medication worked well, but he noticed a pattern: on nights he took Fildena, he often woke up with burning chest pain, regurgitation, or a sour taste in his throat. These symptoms weren’t entirely new, but they were noticeably worse on “Fildena nights”, despite his usual evening dose of omeprazole.

He had assumed this was coincidental, until a gastroenterologist pointed out that sildenafil doesn’t just relax blood vessels. It also acts on smooth muscle throughout the body, including in the lower esophageal sphincter (LES), the valve that normally helps keep stomach acid from rising.

This vignette isn’t unique. As PDE-5 inhibitors like sildenafil continue to be prescribed to millions of men globally, understanding their effects beyond the reproductive system is increasingly important, especially in patients who already have esophageal motility issues or acid reflux.

PDE-5 Inhibitors and Smooth Muscle in the Esophagus

Sildenafil and other phosphodiesterase type 5 (PDE-5) inhibitors are best known for their effects on vascular smooth muscle, where they promote vasodilation by enhancing nitric oxide (NO) mediated signaling. The mechanism hinges on inhibition of the PDE-5 enzyme, which breaks down cyclic guanosine monophosphate (cGMP) a key second messenger in smooth muscle relaxation. When cGMP levels remain elevated, smooth muscle stays relaxed longer.

What’s less widely appreciated is that this same mechanism is at work throughout the gastrointestinal tract, including the esophagus. The lower esophageal sphincter (LES) and the esophageal body rely in part on nitrergic neurotransmission to coordinate relaxation during swallowing. Increasing cGMP levels pharmacologically via PDE-5 inhibition can theoretically reduce LES tone and dampen peristaltic amplitude, especially in patients with already borderline motility.

Indeed, the esophagus contains both circular and longitudinal smooth muscle fibers, and its function is tightly regulated to ensure effective bolus transport and reflux prevention. Interfering with this balance, even slightly, could have clinical consequences, particularly for individuals with GERD, hiatal hernia, or ineffective esophageal motility (IEM).

While this effect might sound like a side note in pharmacology, its clinical relevance is increasingly evident, particularly in patients like Mr. K. who take sildenafil regularly and already have a weakened barrier against reflux.

Evidence Snapshot: Systematic Reviews and Meta-Analyses

Recent studies have provided strong evidence that PDE-5 inhibitors affect esophageal motility, particularly by lowering lower esophageal sphincter (LES) pressure and weakening peristaltic amplitude. A 2023 meta-analysis published in BMC Gastroenterology pooled data from randomized trials and crossover studies evaluating sildenafil, vardenafil, and tadalafil. The results were consistent: these agents reduced mean LES pressure by 8 to 10 mmHg on average. They also diminished peristaltic wave strength in the esophageal body, especially in individuals with baseline hypomotility.

Another systematic review (PMC10201782) confirmed these findings and contextualized them in both therapeutic and adverse-use scenarios. In disorders like achalasia, where the LES is pathologically tight, PDE-5 inhibitors may provide benefit by facilitating relaxation and improving bolus passage. However, in patients with GERD or ineffective esophageal motility (IEM), these same effects may worsen acid exposure by reducing LES competence and slowing clearance.

Of note, the timing of administration matters. Peak plasma concentrations of sildenafil occur within 30 120 minutes, overlapping with the period when patients are often eating or reclining. The effect is dose-dependent and tends to be more pronounced at 100 mg doses (the strength often sold as Fildena). These data suggest that evening or bedtime use of sildenafil may be problematic for individuals already struggling with reflux, particularly if they lie down shortly after dosing. While these findings don’t imply contraindication, they underscore the need for cautious prescribing and patient-specific counseling.

Practical Takeaways: When Fildena May Worsen Reflux Symptoms

Although Fildena (sildenafil) is well tolerated in most patients, those with esophageal motility disorders or reflux-prone anatomy may need to adjust how and when they take it. Patients with chronic GERD, hiatal hernia, or ineffective esophageal motility (IEM) are more vulnerable to the effects of lowered LES pressure.

If baseline barrier function is already weak, adding a smooth muscle relaxant like sildenafil may tip the balance further in favor of gastric reflux. Evening dosing, especially after a large meal or combined with alcohol, can worsen this risk. Sildenafil’s peak activity coincides with postprandial reflux windows and the period of recumbency if taken before bed. For reflux-sensitive patients, it may be better to use sildenafil earlier in the day, ideally at least two hours after eating, and to remain upright for several hours afterward.

Some individuals may also benefit from taking a low-dose PPI or antacid alongside sildenafil, though this does not counteract the mechanical effects on the LES or esophageal peristalsis. Lifestyle habits, like elevating the head of the bed or avoiding late-night meals, remain essential adjuncts.

Clinicians should be especially mindful when prescribing PDE-5 inhibitors to patients already taking calcium channel blockers, nitrates, or agents that also reduce LES tone. A simple medication timing adjustment or reflux strategy can often prevent uncomfortable and avoidable symptoms.

Conclusion and Patient Checklist

As the use of PDE-5 inhibitors like Fildena becomes more widespread particularly among adults over 40 it’s important to understand their effects beyond erectile tissue. While sildenafil’s vascular smooth muscle relaxation is what makes it effective for erectile dysfunction, the same pharmacologic mechanism can influence the gastrointestinal tract, including the esophagus. For most users, this won’t lead to noticeable issues. But for patients with baseline GERD, weak LES tone, or esophageal motility disorders, the risk of exacerbating reflux symptoms is real.

This doesn’t mean Fildena is unsafe or incompatible with acid reflux. Rather, the timing, posture, and overall reflux management strategy matter more in these individuals. The key is patient education and personalization a quick conversation about how sildenafil affects esophageal function can lead to meaningful improvements in comfort and quality of life.

In addition, prescribing clinicians should be aware that combination effects for example, when sildenafil is taken with alcohol, heavy meals, or other smooth muscle relaxants can amplify reflux risk. Reviewing medications, habits, and symptom timing can help clarify whether adjustments are needed.

To guide patients in daily life, a simple checklist may help:

With small adjustments, most patients can continue using sildenafil safely and effectively, even if they’re managing reflux. Awareness, and not alarm, is what makes the difference.

References

1. Li, Y., Zhang, Y., & Zhao, W. (2023). Effects of phosphodiesterase type 5 inhibitors on esophageal motility: A systematic review and meta-analysis. BMC Gastroenterology, 23, Article 456. https://doi.org/10.1186/s12876-023-02787-3
2. Singh, S., Yusoff, I. A., & Zubaidi, A. (2023). The role of PDE-5 inhibitors in esophageal smooth muscle relaxation: A clinical review. Frontiers in Pharmacology. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10201782/