Twenty patients undergoing urgent or emergency surgical procedures where intra-abdominal infection was suspected were treated with doxycycline hyclate. Wound infections involving anaerobic, aerobic, or facultative bacteria developed in four of 11 patients treated with doxycycline alone. Nine other patients received higher doses of doxycycline plus gentamicin sulfate. Five of these had postoperative infections primarily involving anaerobic organisms. Bacteremia with a doxycycline-resistant Bacteroides fragilis developed in one patient during therapy. Serum levels of doxycycline, even at the higher dosage, were below the minimal inhibitory concentrations (MICs) of a number of potential pathogens isolated at the time of surgery. Doxycycline is not indicated in cases of serious intra-abdominal infection unless the infecting flora are known to be susceptible.
(JAMA 238:1933-1935, 1977)