Clinical experience with linezolid in the treatment of resistant gram-positive infections.

This study presents our clinical experience with linezolid in 19 patients with serious resistant gram-positive infections enrolled as part of the compassionate study. In this prospective, non-randomized, noncomparative study, 19 patients were enrolled as part of the National Compassionate Study Protocol conducted by Pharmacia-Upjohn. At the time of this writing, these patients had not been published in the literature. All of the patients had to have documented evidence of serious gram-positive infections in normally sterile sites and should have been unable to tolerate available antimicrobial therapy or be unresponsive to available drugs. Clinical characteristics, laboratory values, and pharmacokinetic and pharmacodynamic parameters were obtained. Patients were followed both short-term and long-term after completion of therapy. Nineteen patients were enrolled: 13 females and 6 males. The average age was 63 years. The average length of therapy with linezolid was 22 days. Methicillin-resistant Staphylococcus aureus (MRSA) was treated in eight patients, methicillin-resistant Staphylococcus epidermidis (MRSE) in two patients, vancomycin-resistant Enterococcus faecium (VREF) in eight patients, and coagulase-negative Staphylococcus in two patients. Co-infecting organisms include Enterococcus species colonization in six patients, Pseudomonas species in one patient, Serratia marcenens in one patient, and Candida albicans in one patient. Sterile sites that were infected included bone and joint (wounds and septic joints) in six patients, gastrointestinal system (hepatobiliary, liver abscess, Crohn's) in five patients, genitourinary (kidney and urine) in two patients, blood in five patients, respiratory in one patient, and aortic valve in 1 patient. Linezolid was given at 600 mg IV every 12 hours with a mean length of therapy of 22 days. Surgical drainage was used in combination with linezolid in 11 of the patients. Seventy nine percent of these patients achieved clinical and microbiologic cure, and none of the deaths reported in this series were related to the drug. Adverse events included skin rash in one patient, mild bone marrow suppression in two patients, and mild elevation in liver function tests in two patients. No life-threatening adverse events were noted. It appears that linezolid, along with surgical intervention (when necessary), appears to be an effective treatment option for resistant gram-positive infections. Long-term studies evaluating the possible resistance rates are necessary.