The influence of baseline parameters on changes in international prostate symptom score with dutasteride, tamsulosin, and combination therapy among men with symptomatic benign prostatic hyperplasia and an enlarged prostate: 2-year data from the CombAT study.
BACKGROUND
Knowledge of baseline factors that influence outcomes for men with benign prostatic hyperplasia (BPH) receiving medical therapy may help to improve outcomes and cost effectiveness.


OBJECTIVE
To examine the influence of baseline parameters on changes in International Prostate Symptom Score (IPSS) and maximum urinary flow rate (Q(max)) in men with BPH receiving dutasteride, tamsulosin, or a combination of the two using 2-yr Combination of Avodart and Tamsulosin (CombAT) study data.


METHODS
CombAT is an ongoing, 4-yr, multicentre, randomised, double-blind study in 4844 men aged >or=50 yr with clinical diagnosis of BPH, IPSS >or=12, prostate volume >or=30 cm(3), prostate-specific antigen (PSA) 1.5-10 ng/ml, and Q(max) >5 and <or=15 ml/s with minimum voided volume >or=125 ml.


METHODS
Daily tamsulosin 0.4 mg, dutasteride 0.5 mg, or the combination.


METHODS
Post hoc analyses of mean IPSS and Q(max) changes from baseline by treatment group and by baseline prostate volume, PSA, age, body mass index (BMI), IPSS, IPSS quality of life (QoL) score, BPH Impact Index score, Q(max), and previous BPH medical therapy.


CONCLUSIONS
Combination therapy was more effective than either monotherapy after 24 mo in improving IPSS in all baseline subgroups, with benefit onset varying by baseline prostate volume. Combination therapy was also more effective in improving Q(max) versus tamsulosin in all subgroups and versus dutasteride in 10 of 18 subgroups. At 24 mo, dutasteride monotherapy resulted in significantly greater IPSS improvements versus tamsulosin in men with lower age, worse symptoms, worse QoL, less bother, higher BMI, greater Q(max), higher prostate volume, and higher PSA at baseline. Post hoc analyses, the lack of placebo control, and the exclusion of men with unsuccessful medical BPH treatment are study limitations.


CONCLUSIONS
Combination therapy with tamsulosin and dutasteride affords the greatest and the most rapid symptomatic benefit among men with higher baseline prostate volume and is effective regardless of previous BPH medical therapy. Dutasteride monotherapy is more effective than tamsulosin in men with higher baseline prostate volume or PSA and worse symptoms.
Roehrborn
Claus G
CG
Department of Urology, UT Southwestern Medical Center, Dallas, TX 75390-9110, USA. claus.roehrborn@utsouthwestern.edu
Siami
Paul
P
Barkin
Jack
J
Damião
Ronaldo
R
Becher
Edgardo
E
Miñana
Bernardino
B
Mirone
Vicenzo
V
Castro
Ramiro
R
Wilson
Timothy
T
Montorsi
Francesco
F
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D001378:Azasteroids / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D000068538:Dutasteride; D004791:Enzyme Inhibitors / Q000627:therapeutic use; D006801:Humans; D008297:Male; D011467:Prostate / Q000033:anatomy & histology / Q000187:drug effects; D017430:Prostate-Specific Antigen / Q000097:blood; D011470:Prostatic Hyperplasia / Q000097:blood / Q000188:drug therapy*; D013449:Sulfonamides / Q000627:therapeutic use*; D000077409:Tamsulosin
D000317:Adrenergic alpha-Antagonists; D001378:Azasteroids; D004791:Enzyme Inhibitors; D013449:Sulfonamides; D017430:Prostate-Specific Antigen; D000077409:Tamsulosin; D000068538:Dutasteride