In a group of over 100,000 men with erectile dysfunction (ED) in the United States, sildenafil was the most commonly-prescribed phosphodiesterase type 5 (PDE5) inhibitor between 2010 and 2015, scientists report in a new Journal of Sexual Medicine study.
Patients were also more likely to continue with sildenafil treatment compared to tadalafil and vardenafil, the authors reported.
PDE5 inhibitors have been an ED treatment option in the U.S. since 1998, when sildenafil (Viagra) was first approved. Tadalafil (Cialis) and vardenafil (Levitra) became available in 2003. Treatment patterns were reported in 2005, but they had not been updated. This study provided a “more contemporary understanding” of how PDE5 inhibitors are being prescribed and used in the present day.
Researchers analyzed data from the MarketScan Commercial and Medicare Supplement Databases for the period of January 1, 2010 to December 31, 2015. They identified 106,206 patients who were age 18 or older when they filled their first prescription for a branded PDE5 inhibitor.
Overall, the men’s average age was 50 years. Approximately 44% had dyslipidemia, 43% had hypertension, 15% had diabetes, and 11% had depression. About 49% started their treatment with sildenafil, 38% started with tadalafil, and 13% started with vardenafil.
Switching patterns were described “within 60 days after the end of day supply of the initial prescription.” During that time, 2.71% of the men taking sildenafil switched to another PDE5 inhibitor, compared to 2.81% of the men taking tadalafil and 3.88% of the men taking vardenafil.
Of those who switched, sildenafil was the most common choice for those who started with tadalafil. Vardenafil users switched to either sildenafil or tadalafil at similar rates.
About 0.54% of the men had an overlap with two drugs. About 0.35% of the men taking sildenafil overlapped with another; for the tadalafil and vardenafil, the rates were 0.75% and 0.62%, respectively.
The authors noted that they did not know how patients chose their initial PDE5 inhibitor or how well patients adhered to their treatment. The reasons for changing drugs were also not known.
“Further insights into the initial [PDE5 inhibitor] selection and reasons for switching between treatments may ultimately help to improve patient experience,” they wrote.
The Journal of Sexual Medicine
Mulhall, John P., MD, et al.
“Phosphodiesterase Type-5 Inhibitor Prescription Patterns in the United States Among Men With Erectile Dysfunction: An Update”
(Published online: March 3, 2020)