Efficacy and safety of dutasteride with tadalafil add-on therapy in patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia

Objective To evaluate the efficacy and safety of add-on therapy with the phosphodiesterase type 5 inhibitor tadalafil in Japanese men with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) treated with dutasteride. Results Twenty-four patients were enrolled. The participants had a median age of 71.0 (64.8-73.0) years and a median prostate volume of 37.3 (29.7-41.8) mL as measured using transabdominal sonography. The efficacy indicators, such as International Prostate Symptom Score (IPSS), quality of life (QOL) score, night-time urinary frequency, and night-time maximum voided volume, improved significantly at 4 weeks, and the effects lasted until 24 weeks (IPSS: 9.5 vs. 17.0, QOL: 2.0 vs. 4.0, nocturia: 2.0 vs. 2.0, night-time maximum voided volume: 290.0 vs. 240.0 mL). Overactive bladder symptom score (OABSS) and sexual health inventory for men (SHIM) significantly improved at 12 weeks, and the effects lasted until 24 weeks (OABSS: 3.0 vs. 5.0, SHIM: 11.0 vs. 7.5). However, maximum urine flow and residual urine volume showed no improvement at any point. Adverse events occurred in two cases. Taken together, add-on therapy with tadalafil was effective for patients with LUTS/BPH resistant to dutasteride monotherapy. In addition, this therapy was not associated with severe adverse events.