Jonathan is 31 years old and presents to A+E with a 2 week history of fevers, myalgia, increased urinary frequency, dysuria and perineal pain. He denies any haematuria, urethral discharge, testicular pain or lumps.
On examination his temperature is 37.8 and rest of observations are unremarkable. Urine dipstick is positive for nitrites and leucocytes and abdominal examination is normal. Rectal examination reveals a tender, warm, swollen prostate and acute prostatitis is suspected.
What is the single most appropriate initial management option?