Temporal Trends in Intracavernosal Injection Therapy and Penile Prosthesis Implantation in the Era of Phosphodiesterase‐5 Inhibitors for Erectile Dysfunction in Australia

INTRODUCTION: Phosphodiesterase-5 inhibitors (PDE5-Is) transformed erectile dysfunction (ED) management as first-line therapy; nonetheless, many patients require second- and third-line options due to inadequate response, side effects, or contraindications. This article evaluates temporal trends in intracavernosal injection (ICI) therapy and penile prosthesis implantation (PPI) in Australia since PDE5-Is introduction. METHODS: MBS item numbers 37415 (ICI), and 37429/37426 (PPI) from 1998 to 2024 were analysed. Data were stratified by age and state, standardised to Australian male population estimates, and reported per 100 000 men. Compound annual growth rates (CAGR) were calculated with break points at major events (release of PDE5-Is, generics, COVID-19). RPBS data were extracted for eligible PDE5-Is and alprostadil from 1998 to 2024. Government expenditure was included and trends compared with international cohorts. RESULTS: Across 260 756 procedures (17 882 PPI; 242 874 ICI), PPI sharply declined in 1996-1999 (CAGR -16.02%/year) after sildenafil introduction but demonstrated sustained growth over time (+7.08%/year 2000-2009 and +4.73%/year 2010-2020). Growth slowed to +1.94%/year 2020-2024 with COVID-related elective surgery disruptions. ICI use collapsed after 1998, stabilised in the 2010s, and contracted further during COVID, equating to a 97% reduction (CAGR -11.4%/year). PPI shifted toward older men aged 55-84 with marked increase in those aged 65-74 and 75-84 years, while ICI has transitioned to almost exclusive use in men over 55 years old. Government expenditure declined more than sixfold between 1996 and 2003 but plateaued since 2010 with PPI and ICI maintaining similar annual cost. From 1999 to 2024, RPBS-subsidised PDE5-Is prescriptions rose from ~440 to 25 500 yearly prescriptions, with early sildenafil predominance shifting to tadalafil, which accounts for 58% of use in 2024. CONCLUSION: There has been a considerable change in trends of invasive ED therapies over the past 30 years since the introduction of PDE5-Is. There has been a significant decline in ICI therapy over the study period, with a recent increased uptake in PPI utilisation.