Antimicrobial prophylaxis in surgery: the role of pharmacokinetics

Even though surgical infection rates have decreased dramatically during the past 25 years, morbidity and mortality of infection in surgical treatment remains substantial. From a pharmacological point of view, the key factor of the efficacy of antibiotic prophylaxis is to attain bactericidal levels of antibiotic in serum and tissues (target site) during the whole intraoperative and early postoperative period. The success of antibiotic prophylaxis is assured only when the chosen antibiotic with a targeted spectrum and high antimicrobial efficacy is available at the critical moment, at the correct site and in sufficiently high concentration to prevent bacterial contamination of the surgical area. It would be desirable for reasons of convenience and cost if a single preoperative administration were sufficient. The pharmacokinetics and the half-life of antibiotics in the serum are directly related to the duration of activity of antibiotic in the tissue. Antibiotics with longer half-lives maintain levels in the tissues for longer periods than do antibiotics with shorter half-lives and they cover with a single dose the time required for prophylaxis even for longer operations. Finally, the application of the pharmacokinetic properties of antibiotics to surgical prophylaxis can provide the surgeon with certainty that adequate coverage and protection with antibiotics are achieved before and throughout the operation.