Linezolid is superior to vancomycin in the treatment of MRSA infections in diabetic patients

In the treatment of nosocomial pneumonia caused by methicillin-resistant strains of Staphylococcus aureus (MRSA), in patients with diabetes, linezolid is superior to vancomycin in terms of clinical efficacy and microbiological - this data was presented at the 51st Interdisciplinary Conference on Antimicrobial Drugs and Chemotherapy (Interscience Conference on Antimicrobial Agents and Chemotherapy), held in September 2011 in Chicago (United States). At the same time, in patients without diabetes mellitus, the effectiveness of the use of the two drugs was comparable.

The conference presented the results of a subgroup analysis of data from a multicentre, randomized, double-blind, controlled study, ZEPHyR which compared linezolid and vancomycin in patients with nosocomial pneumonia caused by MRSA.

The researchers evaluated the results in patients 7 to 30 days after the end of treatment with linezolid (600 mg twice a day iv) or vancomycin (15 mg / kg 2 times a day iv), the dose was adjusted depending on the creatinine clearance).

Patients without diabetes mellitus and with diabetes were comparable in terms of demographics, concomitant diseases, microbiological table and assessment of the severity of pneumonia on the APACHE II scale.

The clinical success rate at the end of treatment in diabetic patients receiving linezolid was 58%, compared to 39% in patients receiving vancomycin (p = 0.03). The microbiological efficacy of the treatment was 59% in the linezolid group and 41% in the vancomycin group (p = 0.03).

Day 28 mortality rates, frequency of drug-related adverse events, frequency of serious adverse events, and frequency of early discontinuation of treatment were similar in the groups compared.

Among patients without diabetes, the clinical success rate of treatment was 53% in patients receiving linezolid and 49% in patients receiving vancomycin (p = 0.6). The microbiological efficacy of the treatment was 56% in the linezolid group and 50% in the vancomycin group (p = 0.37).

As with data analysis in diabetic patients, 28-day mortality, frequency of drug-related adverse events, frequency of serious adverse events, and frequency of early discontinuation in groups compared do not differ statistically significantly.

The data obtained are consistent with the results of previous studies which have shown that linezolid is at least as effective as vancomycin in the treatment of nosocomial pneumonia, including ventilator-associated pneumonia caused by strains of Staphylococcus aureus resistant to methicillin.