Safety profile and signal detection of phosphodiesterase type 5 inhibitors for erectile dysfunction: a Food and Drug Administration Adverse Event Reporting System analysis

Background: Phosphodiesterase type 5 inhibitors (PDE5Is) are generally well tolerated but have been associated with uncommon and significant adverse events (AEs).

Aim: This study aims to investigate and compare the characteristics of AEs associated with PDE5Is used for erectile dysfunction and identify any safety signals in a postmarketing surveillance database between 2010 and 2021.

Methods: A descriptive analysis was conducted for all AEs reported to the Food and Drug Administration Adverse Event Reporting System for 4 PDE5Is-avanafil, sildenafil, tadalafil, and vardenafil-indicated for erectile dysfunction between January 2010 and December 2021. The frequency of the most reported AEs and outcomes were identified. A disproportionality analysis based on proportional reporting ratio (PRR) and reporting odds ratio (ROR) was conducted for the most common and clinically important AEs to identify signals to gain insights into potential differences in safety profiles.

Outcomes: The outcome measures of the study are frequency of reported AEs and outcomes following AE.

Results: A total of 29 236 AEs were reported for PDE5Is during the study period. The most reported AE was "drug ineffective" with 7115 reports (24.3%). Eight safety signals were detected across the 4 drugs. Key signals were sexual disorders (PRR, 3.13 [95% CI, 2.69-3.65]; ROR, 3.24 [95% CI, 2.77-3.79]) and death (PRR, 3.17 [2.5-4.01]; ROR, 3.211 [2.52-4.06]) for sildenafil, priapism (PRR, 3.63 [2.11-6.24]; ROR, 3.64 [2.12-6.26]) for tadalafil, and drug administration error (PRR, 2.54 [1.84-3.52]; ROR, 2.6 [1.86-3.63]) for vardenafil. The most reported outcomes were other serious events with 6685 events (67.2%) and hospitalization with 1939 events (19.5%).

Clinical implications: The commonly reported AEs and detected signals may guide clinicians in treatment decision making for men with erectile dysfunction.

Strengths and limitations: This is the first comprehensive report and disproportionality analysis on all types of AEs associated with PDE5Is used for erectile dysfunction in the United States. The findings should be interpreted cautiously due to limitations in the Adverse Event Reporting System, which includes self-reports, duplicate and incomplete reports, and biases in reporting and selection. Therefore, establishing a causal relationship between the reported AEs and the use of PDE5Is is uncertain, and the data may be confounded by other medications and indications.

Conclusion: PDE5Is demonstrate significantly increased risks of reporting certain clinically important AEs. While these events are not common, it is imperative to continually monitor PDE5I use at the levels of primary care to national surveillance to ensure safe utilization.