Tigecycline Linked to Increased Risk of Carbapenem-resistant K. pneumoniae Infections

PHILADELPHIA, PA—Patients with carbapenem-resistant Klebsiella pneumoniae who are hospitalized and treated with a tigecycline-based regimen are at high risk of readmission with recurrent disease, contributing to its spread in healthcare systems, results of a study reported at IDWeek 2014.

Carbapenem-resistant K. pneumoniae is an emerging threat, said Julia Messina, MD, MSc, of Duke University, Durham, NC. She and her colleagues evaluated readmissions for the disease using data from the prospective, multicenter Consortium on Resistance against Carbapenems in K. pneumoniae, or CRaCKle, which includes 21 hospitals in the Great Lakes region.

Patients hospitalized between December 24, 2011 and July 1, 2013 were included in the consortium if carbapenem-resistant K. pneumoniae was isolated with a positive culture during that time period and they were discharged alive.

All readmissions during which carbapenem-resistant K. pneumoniae was again found were documented, with risk factors evaluated in multivariable logistic models.

Of 287 unique patients included, 109 (38%) had carbapenem-resistant K. pneumoniae infection, which was primarily recovered from urine (67%). Among these patients, 56 (20%) had a carbapenem-resistant K. pneumoniae readmission within 90 days.

Risk factors for readmission included history of cancer (OR 2.74; 95% CI 1.22–5.96, P=0.01) and renal insufficiency (OR 2.06; 95% CI 1.05–3.96, P=0.03).

A total of 160 of the 287 patients (56%) received antibiotic treatment for carbapenem-resistant K. pneumoniae during their index hospitalization. In these 160 patients, 65 (41%) received aminoglycoside-based regimens, 49 (31%), tigecycline-based regimens, 27 (17%) colistin-based regimens, and 19 (12%) other regimens.

Receiving a tigecycline-based regimen was associated with an increased risk for carbapenem-resistant K. pneumoniae readmission, Dr. Messina reported. Of the patients who received tigecycline, 14 (28%) were readmitted within 90 days, compared with 14% of patients who received any of the other treatment regimens. After adjusting for infection status, source, renal failure, and cancer history, the odds ratio for tigecycline for 90-day carbapenem-resistant K. pneumoniae readmission was 2.71 (95% CI 1.14–6.48; P=0.02).