Abstract Background Phosphodiesterase type 5 inhibitors (PDE5i) are widely accepted as first-line therapy for erectile dysfunction (ED), offering favorable efficacy and tolerability. However, limited data exist on the duration of their effectiveness before surgical intervention becomes necessary. This study aims to evaluate the time interval between initiation of PDE5i therapy and subsequent penile prosthesis (PP) implantation, and to identify potential predictors of this duration. A retrospective analysis was conducted on ED patients who underwent PP surgery after initiating PDE5i therapy between January 2019 and August 2022. Clinical and laboratory data were retrieved from hospital records, including patient demographics, comorbidities, and duration of PDE5i use prior to surgery. Results Study Population Characteristics: A total of 98 patients were included in the study. The mean age of the cohort was 56.1 ± 11.5 years, with a mean BMI of 29.8 ± 4.4 kg/m2. The majority of the patients had comorbidities (87; 88.8%), with hypertension present in 53 patients (54.1%) and diabetes mellitus in 74 patients (75.5%). A total of 31 patients (31.6%) were current smokers. The mean glucose level was 7.6 ± 2.7 mmol/L, and the mean HbA1c was 6.9 ± 1.3%. The remaining laboratory test results are presented in Table 1. With regard to PDE5i use, 27 patients (27.6%) used sildenafil, 76 (77.6%) used tadalafil, and 13 (13.3%) used vardenafil. A total of 22 patients (22.4%) were on combination PDE5i therapy (daily 5 mg tadalafil and 50/100 mg sildenafil). The mean duration from initiation of PDE5i therapy to PP implantation was 34.9 ± 24.8 months and 87 (88.8%) patients received an inflatable PP, while 11 (11.2%) received a malleable prosthesis. The mean cylinder size was 21.8 ± 1.9 cm. Comparison Between Early and Late Surgery Groups: Patients were stratified into two groups based on the median duration from PDE5i initiation to PP implantation: 29 months (n = 46) and ≥ 29 months (n = 52). The mean age in the 29-month group was 58.2 ± 10.8 years, compared to 54.3 ± 11 years in the ≥29-month group (p = 0.08). Among the various demographic, clinical, laboratory, and surgical variables, only the mean total testosterone level was found to be significantly lower in the 29-month group (14.2 ± 3.7 nmol/L) compared with the ≥29-month group (18.5 ± 6.7 nmol/L) (p = 0.004). Comparison of patients' characteristics in those who performed PPI or ≥ 29 months is presented in Table 2. Conclusion The findings suggest that patients typically require penile prosthesis surgery approximately three years after starting PDE5i therapy. Testosterone levels may influence this progression, whereas comorbid conditions appear less predictive. Further large-scale studies are needed to validate these findings and better understand the factors affecting the longevity of medical therapy in ED management.
Cangüven et al. (Sun,) studied this question.