Treatment of Acute Bacterial Prostatitis
For acute bacterial prostatitis, initiate broad-spectrum antibiotics targeting gram-negative organisms—ciprofloxacin 400 mg IV twice daily or oral ciprofloxacin for outpatients, piperacillin-tazobactam IV, or ceftriaxone IV for hospitalized patients—and continue treatment for 2-4 weeks total. 1, 2
Initial Assessment and Diagnostic Workup
Perform a gentle digital rectal examination to assess for a tender, enlarged, or boggy prostate, but avoid vigorous prostatic massage or vigorous manipulation as this can precipitate bacteremia. 1, 3
Obtain the following diagnostic tests:
- Midstream urine culture to identify the causative organism and guide antibiotic therapy 1, 3
- Blood cultures, especially in febrile patients 1
- Complete blood count to assess for leukocytosis 1
- Transrectal ultrasound in selected cases to rule out prostatic abscess 1
Pathogen Profile
Gram-negative bacteria cause 80-97% of acute bacterial prostatitis cases, with Escherichia coli being the most common, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa. 1, 2 Gram-positive organisms (Staphylococcus aureus, Enterococcus species, Group B streptococci) account for the remainder. 1
Antibiotic Selection and Treatment Duration
Outpatient Management
For patients who are clinically stable, not systemically ill, able to tolerate oral intake, and able to urinate voluntarily:
- Ciprofloxacin (oral) is the first-line choice with a 92-97% success rate 2
- Alternative: Levofloxacin (oral) 4, 5
- Duration: 2-4 weeks total 1, 2
The fluoroquinolones are preferred because they achieve excellent prostatic tissue penetration with concentration ratios up to 4:1 (prostate:serum). 6 However, fluoroquinolone resistance should ideally be less than 10% in your local area for empiric use. 1
Inpatient Management
Hospitalize patients who are systemically ill, unable to urinate voluntarily, unable to tolerate oral intake, or have risk factors for antibiotic resistance:
- Ciprofloxacin 400 mg IV twice daily 1
- Piperacillin-tazobactam IV 2, 3
- Ceftriaxone IV 2, 3
- Consider adding doxycycline to ceftriaxone for broader coverage 3
Transition to oral antibiotics once the patient is clinically improved and afebrile, typically after 48-72 hours of IV therapy. 1 Complete the full 2-4 week course with oral fluoroquinolones. 1, 2
Tailoring Therapy Based on Local Resistance
Consider local resistance patterns when selecting empiric antibiotics. 1, 4 For patients with risk factors for antibiotic resistance (recent antibiotic use, healthcare-associated infections, recent urologic procedures), consider broader spectrum options initially. 1
Follow-up and Monitoring
Assess clinical response after 48-72 hours of treatment. 1 If there is no improvement in symptoms after 2-4 weeks, stop treatment and reconsider the diagnosis or obtain repeat cultures. 7 If there is improvement, continue treatment for the full 2-4 week course to achieve clinical cure and eradicate the pathogen. 7
Common Pitfalls to Avoid
- Do not perform vigorous prostatic massage during acute infection—this significantly increases bacteremia risk 1, 3
- Do not use amoxicillin or ampicillin empirically due to very high worldwide resistance rates 8
- Do not stop antibiotics prematurely—inadequate treatment duration can lead to chronic bacterial prostatitis 7, 5
- Do not forget to consider prostatic abscess in patients who fail to improve after 48-72 hours of appropriate antibiotics 1