Sildenafil prescribed for erectile dysfunction may induce esophageal symptoms

Phosphodiesterase 5 (PDE-5) inhibitors (sildenafil, tadalafil, and vardenafil) effects on esophageal motility: a systematic review

BACKGROUND

Esophageal motility disorders are a group of disorders associated with dysfunctional swallowing resulting from impaired neuromuscular coordination. Phosphodiesterase 5 (PDE-5) inhibitors induce smooth relaxation and are proposed as a treatment option for esophageal motility disorders such as achalasia.

METHODS

This study is conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). We systematically searched MEDLINE/ PubMed, Scopus, EMBASE, and Web of Science databases for esophageal outcomes of individuals treated with PDE5 inhibitors. A random effect meta-analysis was conducted.

RESULTS

A total of 14 studies were included. They were conducted in different countries, with Korea and Italy having the highest number of articles. The main drug assessed was sildenafil. PDE-5 inhibitors resulted in a significant reduction in lower esophageal sphincter pressure (SMD - 1.69, 95% CI: -2.39 to -0.99) and the amplitude of contractions (SMD - 2.04, 95% CI: -2.97 to -1.11). Residual pressure was not significantly different between the placebo and sildenafil groups (SMD - 0.24, 95% CI: -1.20 to 0.72). Furthermore, a recent study reported contractile integral, stating that ingestion of sildenafil leads to a significant reduction in distal contractile integral and a significant increase in proximal contractile integral.

CONCLUSION

PDE-5 inhibitors significantly reduce LES resting pressure and esophageal peristaltic vigor, decreasing esophageal body contractility and contraction reserve. Therefore, using these drugs in patients affected by esophageal motility disorders may potentially improve their condition regarding symptom relief and prevention of further associated complications. Future reports investigating larger sample size is necessary in order to establish definite evidence regarding the efficacy of these drugs.

Expression of the PDE5 enzyme on human retinal tissue: new aspects of PDE5 inhibitors ocular side effects

OBJECTIVE

We tested the effect of two phosphodiesterase type-5 (PDE5) inhibitors, sildenafil and tadalafil, on ophthalmic artery (OA) blood flow velocity and investigated the presence of the PDE5 enzyme on human retinal tissue in comparison with the PDE6 enzyme localization.

METHODS

Using Colour Doppler ultrasonography (CDU) we investigated, in 30 healthy young subjects (27.8 years of age; range, 24.3-33.7 years), the effects of a single oral dose of sildenafil (100 mg), tadalafil (20 mg), and placebo on OA blood flow velocity. Western blot for PDE6 and PDE5 protein expression was performed on frozen samples of human retina, testis, sperm, skin, and corpus cavernosum. Immunohistochemistry was performed on two ocular globes from dead donors.

RESULTS

CDU showed a relationship between the administration of PDE5 inhibitors and OA blood flow velocity modifications in a time-dependent manner. Western blot and immunohistochemical analysis showed PDE6 and PDE5 presence in human retinal tissue and gave a map of its distribution.

CONCLUSION

We demonstrated that (a) tadalafil and sildenafil are able to modify the OA flux in a time-dependent manner; (b) the PDE5 enzyme is expressed on retinal and choroid vasculature (smooth muscle and endothelial cells), on ganglion and bipolar cells; (c) human retinal tissues express the PDE6 enzyme in the rod and cone photoreceptors; (d) visual side effects after PDE5 inhibitors administration may be linked to a specific effect on the PDE5 enzyme; and (e) the PDE5 enzyme may have a physiologic role on ganglion and bipolar cells that need to be further investigated.

Various Adverse Effects and Behaviors Associated with Sildenafil; Another Case of Glycemic Control Problems Associated with Fluoroquinolone Therapy; The First Case of Pure White Cell Aplasia in a Patient Treated with Imipenem–Cilastatin; High-Output Heart Failure Associated with Anagrelide; Renal Dysfunction Attributed to Oral Acyclovir Therapy; Progressive Multifocal Leukoencephalopathy after Natalizumab Therapy – Reiterating the Importance of Reporting Adverse Events; A Final Note on Medication Adherence

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