Treatment outcomes in pelvic inflammatory disease optimally include rapid resolution of symptoms, preservation of fertility and low rates of ectopic pregnancy. Most randomized, controlled trials assess only the first outcome—short-term control of symptoms. In an editorial, Ross reviewed the clinical evidence supporting antibiotic therapy for pelvic inflammatory disease (PID).
The available evidence depends heavily on inpatient parenteral antibiotic therapy, and study results are difficult to extrapolate to out-patient oral antibiotic therapy. A two-week treatment period is common clinical practice, but the optimal duration of treatment is uncertain. Selection of therapy is aided only in part by microbiologic studies showing a wide variety of bacteria in the fallopian tubes of women with PID, but these studies cannot determine whether some or all of the bacteria are primary pathogens.
Most guidelines recommend outpatient treatment of PID with a parentally administered cephalosporin followed by doxycycline and metronidazole, or a combination of orally administered ofloxacin with metronidazole. Clinical cure rates have been higher with ofloxacin (about 95 percent) and its combinations than with the more commonly used combination of doxycycline and metronidazole (about 75 percent). Failure of the doxycycline and metronidazole regimen may be caused by limited bacteriologic coverage. Another reason for the failure of this regimen may be the presence of resistant Neisseria gonorrhoeae and other facultative bacteria, such as coliforms, Garnerella vagi-nalis and Streptococcus viridans, which are commonly found in the fallopian tubes of women with PID.
The author notes that continued use of the combination of orally administered doxycy-cline and metronidazole is difficult to justify because of a lower cure rate compared with alternative therapies.