This patient with likely acute bacterial prostatitis should begin empiric treatment with a fluoroquinolone, such as ciprofloxacin. Acute prostatitis most commonly results from an ascending urethral infection, although bacterial cystitis or epididymo-orchitis may be an underlying source of infection. Patients most often present with fever, chills, malaise, nausea and vomiting, dysuria, urgency, frequency, and pain in the lower abdomen, perineum, and rectum. The onset of symptoms is typically rapid. On physical examination, the prostate is tender and tense or boggy. Excessive palpation of the prostate should be avoided because it may contribute to bacteremia. As was done with this patient, blood and urine cultures should be obtained, and empiric broad-spectrum antibiotics should be started. Gram-negative bacillary organisms, including Escherichia coli, Serratia species, and Klebsiella species, are the most common causative agents in patients with uncomplicated acute bacterial prostatitis who are at low risk for sexually transmitted infections (STIs). The course of therapy with a fluoroquinolone is at least 14 days and up to 4 weeks. Trimethoprim-sulfamethoxazole is also an appropriate first-line choice if the isolate is known to be susceptible or if the rate of E. coli resistance in the community is less than 20%.
Ampicillin, which had been an alternative therapeutic option for prostatitis, can no longer be recommended as empiric therapy because of the high rate of resistance among community-acquired microorganisms.
A single dose of ceftriaxone, 250 mg intramuscularly, is indicated for uncomplicated acute bacterial prostatitis in patients at risk for STIs with Neisseria gonorrhoeae or Chlamydia trachomatis. Generally, men younger than 35 years are at risk for infection with these organisms. Doxycycline, 100 mg twice daily for 10 days, is also indicated in these patients. This patient is not sexually active and therefore does not require coverage for possible STIs.
Treatment with a carbapenem, such as meropenem, should be reserved for systemically ill patients who require hospitalization or when a fluoroquinolone-resistant organism is a concern. The incidence of fluoroquinolone-resistant E. coli is very high (up to 90%) following prostate biopsy.