Results
A total of 132,993 and 826 reports of ADR were found for PDE5is and intracavernousal drugs (i.e., alprostadil and/or papaverine), respectively. Of these, 632 were priapism (PDE5is: 550; 0.41%, and intracavernousal drugs: 82; 9.92%). Among PDE5is, sildenafil had the highest number of priapism reports (360; 0.42%), followed by tadalafil (140; 0.4%), vardenafil (49; 0.45%), and avanafil (1; 0.11%) (table 1).
The most frequently reported indication for the use of PDE5is for patients eighteen or older was erectile dysfunction (n=34,608; 43.36%) (table 2). In individuals under eighteen, almost half the indications for PDE5i use were left blank in the dataset (n=405; 43.5%) and the second most common indication was pulmonary hypertention (n=354; 38.02%) followed by erectile dysfunction (n=34; 3.65%).
Table 1 shows the difference in the RORs of PDE5i agents. We observed a 25-fold dominance in odds of reporting priapism for intracavernousal remedies (ROR=34.7; CI 95%: 27.12 - 43.94; p<0.001) in comparison with PDE5is (ROR= 1.38; CI 95%: 1.24 - 1.54; p<0.001). Priapism was most commonly reported in sildenafil among PDE5is.
For all PDE5i agents, the 12-17 years age group was associated with a significantly higher reporting of priapism (n=7; ROR=9.49; CI 95%: 3.76 - 19.93; p<0.001) followed by 2-11 years (n=6; ROR=4.31, CI 95%: 1.57 - 9.4, p<0.001) and 18-44 years (n=106; ROR=3.32, CI 95%: 2.69 - 4.06, p<0.001) (Fig. 1).
The disproportionality signals for consumers under eighteen years of age were nearly four times bigger that the ones eighteen or older for both all PDE5is (n=14; ROR=4.57, CI 95%: 2.48 - 7.73, p<0.001vs. n=281; ROR=1.06, CI 95%: 0.93 - 1.21, p=0.372) and sildenafil (n=12; ROR=4.89, CI 95%: 2.51 - 8.62 p<0.001vs. n=174; ROR=1.08, CI 95%: 0.91 - 1.26, p=0.371). Tadalafil, vardenafil, avanafil, and intracavernousal drugs had no priapism reports under the age of eighteen.
Finally, among all PDE5i consumers with priapism, 133 patients (24.18%) recovered without sequela, and the recovery rate was higher in the eighteen or older age group than those under eighteen (21.43% vs. 35.94%), although not statistically significant. The outcomes of priapism events due to PDE5is are listed in table 3.