Korean J Urol.  2015 Apr;56(4):305-309. 10.4111/kju.2015.56.4.305.

Significance of intraprostatic architecture and regrowth velocity for considering discontinuation of dutasteride after combination therapy with an alpha blocker: A prospective, pilot study

• Shindo T
• Hashimoto
• Shimizu T
• Itoh N
• Masumori N

• KMID: 2155306
• DOI: http://doi.org/10.4111/kju.2015.56.4.305

Abstract

PURPOSE
We conducted a prospective single-center study to evaluate the possibility of discontinuation of dutasteride after combination therapy with an alpha blocker for benign prostatic hyperplasia (BPH).
MATERIALS AND METHODS
We prospectively treated BPH patients with an alpha blocker and dutasteride (0.5 mg/d). Patients who had been treated with alpha blockers against BPH for more than 2 months were eligible, and 20 patients were included in the study. After 6 months of combination therapy, dutasteride was discontinued. Patients were followed for 12 months after cessation. Prostate volume, intraprostatic architecture determined by transrectal ultrasound, peak urinary flow rate, postvoid residual urine volume, and the serum prostate-specific antigen level were evaluated every 6 months, and the International Prostate Symptom Score and overactive bladder symptom score (OABSS) every 3 months. Patients were allowed to restart dutasteride during the follow-up period according to their desire.
RESULTS
Twelve patients (12/20, 60%) restarted the combination therapy from 6 to 12 months into the follow-up period. For patients who restarted dutasteride, the prostate volume and OABSS had increased and worsened after discontinuation, respectively. A visible transition zone with a clear border on transrectal ultrasound at baseline and regrowth of the prostate after discontinuation of dutasteride were risk factors for restarting the therapy (Mann-Whitney U test: p=0.008, p=0.017).
CONCLUSIONS
Prostatic enlargement after discontinuation of dutasteride differs among patients. Rapid regrowth of the prostate leads to deterioration of storage symptoms and a tendency to restart dutasteride. Baseline intraprostatic architecture may be a predictive factor for whether the patient is a good candidate for discontinuation.

Keyword

5-alpha reductase inhibitors; Dutasteride; Prostatic hyperplasia

MeSH Terms

5-alpha Reductase Inhibitors/administration & dosage/adverse effects
*Adrenergic alpha-Antagonists/administration & dosage/adverse effects
Aged
Drug Monitoring
Drug Therapy, Combination/methods
*Dutasteride/administration & dosage/adverse effects
Follow-Up Studies
Humans
Japan
Male
Middle Aged
Organ Size
Prospective Studies
*Prostate/drug effects/pathology/ultrasonography
Prostate-Specific Antigen/analysis
*Prostatic Hyperplasia/drug therapy/pathology
Secondary Prevention/methods/statistics & numerical data
Treatment Outcome
Withholding Treatment
5-alpha Reductase Inhibitors
Adrenergic alpha-Antagonists
Dutasteride
Prostate-Specific Antigen

Figure

• 

  Fig. 1 (A) Changes of clinical parameters (mean values) in all 20 patients from baseline to 6 months after discontinuation of dutasteride. (B) Changes of clinical parameters (mean values) in 12 patients from baseline to the point of restarting dutasteride. IPSS, International Prostate Symptom Score; OABSS, overactive bladder symptom score; Qmax, peak urinary flow rate; NS, not significant. **p<0.01.***p<0.001. Wilcoxon signed-rank test.

• 

  Fig. 2 Changes of prostate volume (mean values) for groups 1 and 2 from baseline to 6 months after discontinuation.

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