Alpha-blocker test: alternative to pressure-flow study of bladder outlet obstruction and detrusor contractility in patients without an enlarged prostate.
OBJECTIVE
We investigated whether the cause of urinary disturbance in men with a prostate volume < or =20 mL can be determined by analyzing the efficacy of alpha1-adrenoceptor antagonist (alpha-blocker) treatment.


METHODS
Thirty-five men who were >50 years of age, with an International Prostate Symptom Score (IPSS) > or =8 points, a quality of life (QOL) index > or =2 points and a prostate volume </=20 mL were enrolled in the non-enlarged prostate group. Twenty-six men who met the above conditions but who had a prostate volume >20 mL served as controls. The alpha1-adrenoceptor antagonist tamsulosin was administered at a dose of 0.2 mg/day for 4 weeks. Results for the IPSS, QOL index, free flowmetry and pressure-flow studies were obtained before and after tamsulosin administration.


RESULTS
In both groups, tamsulosin improved the IPSS and QOL index and the bladder outlet obstruction index (BOOI) was lowered without reducing the bladder contractility index (BCI). No parameter showed a significant difference in treatment efficacy between the two groups. In the non-enlarged prostate group, both the pretreatment BOOI and BCI correlated with the efficacy of treatment in improving maximum flow rate (Qmax). In the enlarged prostate group, BOOI and BCI did not correlate with Qmax. When Qmax was improved by > or =3.5 mL/s, the positive predictive value for both pretreatment BOOI >40 and BCI >100 was 100% in the non-enlarged prostate group.


CONCLUSIONS
The alpha-blocker test is one method to assess the presence of bladder outlet obstruction and the state of detrusor contractility in men without an enlarged prostate.
Hirayama
Akihide
A
Department of Urology, Prefectural Nara Hospital and Department of Urology, Nara Medical University, Nara, Japan.
Samma
Shoji
S
Yamaguchi
Akira
A
Fukui
Yoshihisa
Y
Matsumoto
Yoshihiro
Y
Fujimoto
Kiyohide
K
Hirao
Yoshihiko
Y
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000503:physiopathology; D013449:Sulfonamides / Q000627:therapeutic use; D000077409:Tamsulosin; D001748:Urinary Bladder Neck Obstruction / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D014563:Urodynamics
D000317:Adrenergic alpha-Antagonists; D013449:Sulfonamides; D000077409:Tamsulosin