A new standard of care: administration of preoperative antibiotics in the operating room.

Surgical site infections increase total hospital expenses and extend the length of hospital stay. Properly administered antibiotics are successful in minimizing postoperative subcutaneous wound infection secondary to perioperative bacterial contamination at the surgical site and are effective in most clean-contaminated surgical procedures. It is imperative that therapeutic levels of antibiotics be present during the time when the wound is open to maximize their effect to prevent the development of surgical wound infections. Only 32 per cent of 97 patients sampled from 1992 to 1994 at the Louisville Veterans Affairs Medical Center were administered preoperative antibiotics within 1 hour prior to surgical incision. Changing the responsibility for preoperative antibiotic administration from ward or holding room nurses to the anesthesiologist in the operating room rendered such antibiotics delivered closer to the induction of anesthesia and subsequent incision. Eighty-eight per cent of 220 patients sampled in 1995 had antibiotics administered within 1 hour of incision. This change in institutional policy of antibiotic administration maximizes the likelihood of appropriate antibiotic tissue levels and thereby their potential efficacy. Routine prophylaxis should be administered as close to the time of induction of anesthesia as possible to provide the best chance for appropriate tissue levels above the minimum inhibitory concentration for potential bacterial contamination.

Clinafloxacin-theophylline drug interaction.

OBJECTIVE: To report an apparent pharmacokinetic interaction between clinafloxacin and theophylline in a patient with chronic obstructive pulmonary disease (COPD). CASE SUMMARY: A patient with a history of COPD was admitted for a fracture of the right femoral neck. Admission medications included extended-release theophylline 400 mg bid. The initial serum theophylline concentration was 81.03 mumol/L (normal 55-110). A subsequent concentration was subtherapeutic (46.62 mumol/L) and the theophylline dosage was increased to 300 mg tid. Therapeutic steady-state concentrations were achieved. The patient later developed pneumonia and was enrolled in a study of nosocomial acquired pneumonia involving clinafloxacin versus ceftazidime. He was randomized to receive clinafloxacin 200 mg iv q12h. After clinafloxacin therapy was initiated, the serum theophylline concentration increased into the toxic range (155.96 mumol/L). Theophylline administration was held for 2 doses and the dosage then reduced to 200 mg tid. Serum concentrations decreased to within the therapeutic range. DISCUSSION: The fluoroquinolones have been shown to interact with the hepatic metabolism of theophylline and increase serum theophylline concentrations. The quinolone metabolite, 4-oxoquinolone, inhibits the N-demethylation of theophylline, leading to a decrease in the clearance of theophylline. The resultant rise in theophylline concentrations corresponds with the decrease in clearance and possible toxicity. In our patient, careful monitoring of theophylline concentrations and dosage adjustments resulted in the restoration of therapeutic serum concentrations. CONCLUSIONS: The observation of this drug interaction between clinafloxacin and theophylline suggests a need for prudent monitoring of theophylline concentrations. Dosage adjustments may be warranted when this combination of medications is used. Such action may prevent significant toxicities and prolonged hospitalization. Further controlled clinical trials in healthy volunteers are needed to substantiate the interaction between clinafloxacin and theophylline.