Dr. Pathak and associates from Kaiser Permanente, Los Angeles published an article in the June 2007 issue of the Journal of Urology, basing the frequency of LHRH agonist serum on testosterone levels instead of a fixed cookie cutter schedule currently used by most physicans.
Patients usually receive a depot injection of an LHRH agonist based upon pharmaceutical recommendations. The most common schedule is every 3 months. Since the real goal should be to maintain serum testosterone at a castrate level of ‹50ng/dl, this study based the dosing interval on when the serum testosterone level exceeded the castrate level (50ng/dl).
Between 2003 and 2005, 42 men were prospectively enrolled in the study. PSA and testosterone levels were obtained prior to initiating LHRH therapy, after 24 weeks and monthly thereafter. If serum testosterone was ‹50ng/dl then the next dose was held until the level exceeded the castrate level. A serum testosterone level >50ng/dl despite LHRH therapy resulted in consideration of second line hormonal therapy.
Mean patient age was 78.5 years, median pretreatment PSA was 15ng/ml, and pretreatment testosterone was 300ng/dl. Mean follow-up was 18 months and median post-treatment PSA was 0.745ng/ml. The median dosing interval was 6.0 months. No patients required more frequent dosing than every 5 months.
The study clearly suggest that personalizing the dosing schedule could have a significant impact on the expense of this treatment. However, intermittent androgen deprivation if it becomes the new standard of care would be even more cost effective along with the personalized dosing schedule.
Pathak AS, Pacificar JS, Shapiro CE, Williams SG
J Urol.177 (6):2132-2135, June 2007
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Joel T Nowak MA, MSW