A 70-year-old man with known benign prostatic hyperplasia (BPH) presents with worsening lower urinary tract symptoms (LUTS), including nocturia x4, hesitancy, and a poor stream. His International Prostate Symptom Score (IPSS) is 18 (moderate). He has no red flag symptoms. Examination reveals a moderately enlarged, smooth prostate. PSA is 2.5 ng/mL. According to NICE CG97, what is the most appropriate initial pharmacological management if conservative measures have been insufficient?