Progression of Lower Urinary Tract Symptoms After Discontinuation of 1 Medication From 2-Year Combined Alpha-blocker and 5-Alpha–reductase Inhibitor Therapy for Benign Prostatic Hyperplasia in Men – A Randomized Multicenter Study

ObjectiveTo investigate the treatment outcome of discontinuing 1 medication from 2-year combination therapy for male benign prostatic hyperplasia/lower urinary tract symptoms.Materials and MethodsPatients with International Prostate Symptom Score ≥8, total prostatic volume (TPV) >30 mL, and maximum flow rate (Qmax) <15 mL/s were randomly assigned to the 5α-reductase inhibitor (5ARI) discontinue (DC-5ARI) or α-blocker discontinue (DC-α-blocker) group. All patients received combination therapy with dutasteride (0.5 mg QD) and doxazosin (4 mg QD) for 2 years and then discontinued either one drug for 12 months. The primary endpoint was the occurrence of resuming medication. The secondary endpoints were the net parameters changed or the need of transurethral resection of the prostate (TURP).ResultsA total of 117 patients in DC-5ARI and 113 in DC-α-blocker group completed the study. The baseline TPV and Qmax were similar between groups before combination therapy. Resumption of combination therapy was significantly more in DC-5ARI than DC-α-blocker group (51.3% vs 31.0%; P = .005). The mean duration from discontinuing to resuming medication was 5.0 ± 4.4 months in DC-α-blocker and 7.8 ± 3.8 months in DC-5ARI group (P <.05). The TPV progression (29.1% vs 8.0%; P <.001) and the need for TURP (14.5% vs 7.1%; P = .043) were significantly higher in DC-5ARI than DC-α-blocker group. Patients with larger TPV (45.8 ± 18.1 mL) had significantly greater need for resuming 5ARI than smaller TPV (36.3 ± 16.9 mL; P = .007), and a lower Qmax might predict resuming α-blocker.ConclusionAfter a 2-year combination therapy, discontinuation of either one drug induced benign prostatic hyperplasia progression in either group. Greater risk of resuming medication and needing TURP were noted in patients who discontinued 5ARI.