If you can possibly stand it, here's another report on Viagra (sildenafil). It comes from the January 2000 issue of the journal Pharmacoeconomics, and compares the three-year costs of different non-surgical treatments for male erectile dysfunction.
The study assumes a managed-care plan with 100,000 enrollees and accounts for the costs of medical evaluation, treatment and follow-up examinations. All numbers are in 1998 U.S. dollars.
The authors warn that there are high costs associated with switching a patient from one treatment to another, so it's best to start with a treatment that the patient will accept.