Antibiotic treatment of acute bacterial prostatitis

Acute bacterial prostatitis is usually caused by Gram-negative bacilli (rod-shaped bacteria). The prostate is a hard place for antibiotics to reach, and few drugs get in at useful concentrations, so the drug chosen needs to be one that does.

For a man who is stable, can pass urine and can take tablets, the first choice is an oral fluoroquinolone, such as ciprofloxacin or ofloxacin, for 14 days. Treatment starts straight away, and the choice of antibiotic should be reviewed when the urine culture results return. At the 14-day review the course can be extended by another 14 days if needed. If a fluoroquinolone is not appropriate, trimethoprim (another antibiotic) for 14 days is the alternative. Treatment is a prolonged course, usually 2 to 4 weeks: weeks, not days.

Supportive care goes alongside the antibiotic: enough fluids and simple analgesia (painkillers) such as paracetamol. These ease symptoms but do not replace the antibiotic.

Fluoroquinolones reach the prostate well, but the MHRA (the UK medicines regulator) advises that they must only be prescribed when other commonly recommended antibiotics are inappropriate, because they can cause long-lasting, disabling and potentially irreversible side effects such as tendon damage and nerve damage. A man given one is told to stop it and seek advice at the first sign of tendon pain, muscle weakness or nerve symptoms.

Hospital assessment is needed if a man is severely unwell, has sepsis or an abscess, cannot pass urine (urinary retention) or take oral antibiotics, or is not improving 48 hours after starting treatment. In a man with weakened defences against infection (immunocompromised), treatment failure may be more likely, so urgent referral for specialist advice can be considered. Surgery is not first line: a prostatic abscess (a pocket of pus in the prostate) is a rare complication that may need surgery.