Login to Access Video or Poster Abstract: MP09-18
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Introduction

So far no studies have investigated whether administration of dutasteride (DUT) could affect the steroid metabolite pathway in symptomatic BPH patients.

Methods

Urine and blood samples, and clinical parameters such as IPSS, QoL score and prostate volume were prospectively collected before and after 0.5 mg daily DUT administration in 60 symptomatic BPH patients. Among the 60 patients, 25 discontinued DUT after treatment at 12 months and urine samples after the withdrawal of DUT treatment were also prospectively collected. Urine samples were evaluated by urinary steroid profile (USP), which could measure all 63 urinary steroid metabolites at a same time. The USP analysis was determined by gas chromatography/mass spectrometry. We evaluated the pharmacological changes in urinary metabolites in USP and their correlations with clinical parameters in BPH patients treated with DUT.

Results

The urinary androsterone/etiocholanolone (An/Et) ratio in the sex-steroid pathway was significantly decreased from 1.39 ± 0.62 to 0.02 ± 0.01 (p<0.01). Urinary metabolites in other steroid pathways such as 5αTHF/5βTHF in the glucocorticoid pathway and 5αTHB/βTHB in the mineralocorticoid pathway were also significantly decreased after DUT treatment. In the 25 patients who discontinued DUT treatment, the mean An/Et ratio at baseline before DUT treatment, just before withdrawal of DUT, one month, 3 months, and 6 months after withdrawal of DUT treatment were 0.01, 1.42, 0.02, 0.18, and 1.17, respectively. All other urinary metabolite ratios such 5αTHF/5βTHF and 5αTHB/βTHB were also changed in a similar manner. Prostate volume, IPSS, and QoL score just before withdrawal of DUT treatment (12 months after DUT treatment) were significantly lower than those at baseline before DUT treatment, but these parameters 3 months and 6 months after withdrawal of DUT were not significantly different from those just before withdrawal of DUT treatment. The mean PSA level at baseline before DUT treatment, just before withdrawal of DUT, and 3 months, and 6 months after withdrawal of DUT treatment were 5.6, 2.3, 3.7, and 5.2 ng/ml, respectively. Significant correlation was observed between the recovery rate of PSA level and the recovery rate of An/Et in USP before and 3 months after withdrawal of DUT (ρ=0.61, p<0.01).

Conclusions

The urinary 5α/5β metabolites in all steroid pathways were strongly suppressed after daily 0.5 mg DUT administration for one month. The recovery rate of PSA after withdrawal of DUT treatment might reflect the recovery rate of 5α/5β steroid metabolites.

Funding

no