UCSF

Purpose: To explore the differences among erectile aids (i.e., phosphodiesterase type 5 inhibitors [PDE5i] and intracavernousal drugs) of the relative risk of priapism and identify age groups at risk. Methods: We queried the World Health Organization global database of individual case safety reports (VigiBase) for records of the ADR with sildenafil, tadalafil, avanafil, vardenafil, papaverine, and alprostadil. Disproportionality analyses (case/non-case approach) were performed to assess the relative risk of priapism reporting in PDE5i consumers compared to intracavernousal drug recipients. Results: From a total of 133,819 ADR events for erectogenic medications, 632 were priapism (PDE5is: n=550, 0.41%; intracavernousal drugs: n=82, 9.92%). We observed a strong signal for priapism induction for intracavernousal drugs than PDE5is (reporting odds ratio [ROR]=34.7; confidence interval [CI] 95%: 27.12 - 43.94 vs. ROR= 1.38; CI 95%: 1.24 - 1.54). For all PDE5i agents, the 12-17 years age group had the highest highest ROR (ROR=9.49, CI 95%: 3.76 - 19.93) followed by 2-11 years (ROR=4.31, CI 95%: 1.57 - 9.4). Disproportionality signals for consumers under eighteen for both all PDE5is as a whole (ROR=4.57, CI 95%: 2.48 - 7.73) and sildenafil (ROR=4.89, CI 95%: 2.51 - 8.62) were significantly stronger than individuals eighteen or older (ROR=1.06, CI 95%: 0.93 - 1.21 and ROR=1.08, CI 95%: 0.91 - 1.26, respectively). Conclusions: While the overall risk of priapism following the oral administration of PDE5is is extremely low compared with intracavernousal remedies, adolescents are at a higher risk of priapism than older men.