Plain Language Summary
Priapism is an erection persisting for over four hours and implicates emergent intervention to prevent the risk of erectile dysfunction in future. Oral phosphodiesterase type 5 inhibitors (PDE5is) are used to treat erectile dysfunction and have rarely been reported to cause priapism. Looking at the largest international database of individual case safety reports for drugs (VigiBase), we aimed to explore the differences among PDE5is of the relative risk of priapism and identify age groups at risk. We identified reports of priapism corresponding to sildenafil, tadalafil, vardenafil, and avanafil in VigiBase from 1994 to 2021 and performed disproportionality analysis calculating the reporting odds ratio (ROR) [i.e., odds of an adverse reaction being reported for a drug in a dataset] for priapism in PDE5is. We found a very small risk of priapism with PDE5is compared with other adverse drug reactions. PDE5i use among young patients was associated with a higher risk of priapism compared to adults, albeit low. Our analysis further confirmed that the risk of priapism amongst older men with erectile dysfunction is extremely rare. This implies that although patient counseling when prescribing PDE5is for adults seems unneeded, providers should be aware of the higher risk of priapism in under-age patients.