Effectiveness of ceftazidime-avibactam for the treatment of infections due to Pseudomonas aeruginosa.

BACKGROUND: Clinical experience with ceftazidime-avibactam (CAZ-AVI) for treatment of infections due to multidrug or extremely resistant (MDR/XDR) Pseudomonas aeruginosa (P. aeruginosa) is limited. METHODS: A retrospective cohort study was conducted on patients with MDR/XDR P. aeruginosa infections treated with CAZ-AVI. The primary outcome was clinical cure by day 14, evaluated by logistic regression adjusted for the propensity score to receive CAZ-AVI as combination therapy. Secondary outcomes were 30-day all-cause mortality, 90-day recurrence, emerging CAZ-AVI resistance, and safety of therapy. RESULTS: Sixty-one first episodes of MDR/XDR P. aeruginosa infection were included. The most common source was lower respiratory tract infection (34.4%), 14.8% episodes developed bloodstream infection and 50.8% had sepsis at presentation. Ceftazidime-avibactam therapy was initiated at a median of 7.0 (interquartile range [IQR]: 3.5-12.0) days from symptom onset; it was used as combined therapy in 29 (47.5%) episodes. Clinical cure rate by day 14 was 54.1% and predictors of response were days to source control (adjusted odds ratio [aOR]: 0.84; 95% confidence interval [CI]: 0.72-0.98; P = 0.024), days until the initiation of CAZ-AVI therapy (aOR: 0.65; 95% CI: 0.49-0.86; P = 0.003), age (aOR: 1.07; 95% CI: 0.99-1.15; P = 0.066) and CAZ-AVI combination therapy (aOR: 0.02; 95% CI: 0.01-0.38; P = 0.009). Rates of 30-day all-cause mortality and 90-day recurrence were 13.1% and 12.5%, respectively. Emergence of drug resistance to CAZ-AVI was not detected. Treatment-related adverse events occurred in three episodes (4.9%). CONCLUSIONS: CAZ-AVI constitutes a valid alternative for the treatment of infections due to MDR/XDR P. aeruginosa.

Fluoroquinolones for the treatment of latent Mycobacterium tuberculosis infection in liver transplantation.

Solid organ transplantation (SOT) is the best treatment option for end-stage organ disease. Newer immunosuppressive agents have reduced the incidence of graft rejection but have increased the risk of infection, particularly due to the reactivation of latent infections due to opportunistic agents such as Mycobacterium tuberculosis. Active tuberculosis (TB) after SOT is a significant cause of morbidity and mortality. Most cases of posttransplant TB are secondary to reactivation of latent tuberculosis infection (LTBI) due to the effects of long-term immunosuppressive therapy. Risk minimization strategies have been developed to diagnose LTBI and initiate treatment prior to transplantation. Isoniazid with vitamin B6 supplementation is the treatment of choice. However, liver transplantation (LT) candidates and recipients have an increased risk of isoniazid-induced liver toxicity, leading to lower treatment completion rates than in other SOT populations. Fluoroquinolones (FQs) exhibit good in vitro antimycobacterial activity and a lower risk of drug-induced liver injury than isoniazid. In the present review, we highlight the disease burden posed by posttransplant TB and summarize the emerging clinical evidence supporting the use of FQs for the treatment of LTBI in LT recipients and candidates.