Utilization and prescription patterns of phosphidiesterase-5 inhibitor medications in the United States military health system.

Phosphodiesterase-5 inhibitors (PDE-5Is) are the first-line medical treatments for erectile dysfunction (ED), but are often restricted in public formularies. This study assesses PDE-5I usage among active-duty service members before and after the addition of sildenafil to the formulary of the Military Health System (MHS) in 2012. To assess, a cross-sectional evaluation was conducted, utilizing encounter and pharmaceutical claims data from the Military Health System Data Repository between 2010 and 2014. Separate zero-inflated, negative binomial models were used to assess changes in usage rates by prescription and by number of pills issued, for 37 947 patients. Increased PDE-5I usage was noted with select comorbidities, notably mental health and neurologic conditions. There was significant proportional variation in medication distribution following inclusion of sildenafil within the MHS formulary, with a minimal demographic impact on medication models. The average number of prescriptions decreased, while the quantity of distributed medications increased. A significant portion of PDE-5I recipients were young men, under 25 years old, who received medications on the first visit, which invites speculation about the effectiveness of treatment and appropriateness of use. Future studies aimed at evaluating prevalence in younger population may be of benefit.