Drug use investigation on the safety and efficacy of tigecycline in Japan (all-case post-marketing surveillance).

Introduction: We conducted a drug use investigation to investigate the safety and efficacy of tigecycline, which has been approved for clinical use for the treatment of multidrug-resistant gram-negative infections in Japan.

Methods: This was an open-label, observational, multicenter cohort study that included all patients who received tigecycline.

Results: A total of 116 patients were registered between December 2012 and April 2016 and all of them were evaluated for safety and efficacy. Among them, 64 patients aged ≥65 years (55.2%) and five children aged <15 years (4.3%) were included. Of these patients, 47 (40.5%) met the approved indications of tigecycline. Adverse drug reactions (ADRs) were observed in 41 patients (35.3%) with a total of 74 events. Serious ADRs were observed in 15 patients (12.93%) with a total of 33 events. There were 42 deaths, and 6 of these were considered to be caused by ADRs. Among the 116 patients, 65 achieved clinical response at the end of the observation period, and the efficacy rate was 73.9%. Furthermore, 46 patients were assessed as "cure" at the test of cure visit, and the cure rate was 59.0%. The eradication rate was 47.5% at the end of the observation period. Classified by pathogenic bacteria, the eradication rate of patients infected with the approved pathogens was 54.5%.

Conclusions: Tigecycline was well-tolerated, and no additional safety concerns were noted. It was effective considering that most patients had poor physical conditions. The overall benefit-risk balance of tigecycline was favorable.