Activity of Plazomicin against Enterobacteriaceae Isolates Collected in the United States Including Isolates Carrying Aminoglycoside-Modifying Enzymes Detected by Whole Genome Sequencing

The Role of Novel Antibiotics in the Management of Diabetic Foot Infection

Diabetic foot infection is a frequent and potentially life-threatening complication of diabetes mellitus. Antibiotic treatment is the cornerstone of management of diabetic foot infection but the rising prevalence of antibiotic resistance has resulted in increasing rates of treatment failure. In this context, the development of several novel antibiotics might represent a useful tool in severe diabetic foot infections caused by multidrug-resistant bacteria. In the present review, we summarize the safety and efficacy of novel antibiotics in patients with diabetic foot infection. Relevant data are limited, and randomized controlled studies that evaluated the role of these agents in this field are lacking. Until more robust data are available, cefiderocol and dalbavancin, which have been studied more extensively in patients with bone infections, might be attractive options in carefully selected patients with severe diabetic foot infection.

Aminoglycoside Revival: Review of a Historically Important Class of Antimicrobials Undergoing Rejuvenation

Aminoglycosides are cidal inhibitors of bacterial protein synthesis that have been utilized for the treatment of serious bacterial infections for almost 80 years. There have been approximately 15 members of this class approved worldwide for the treatment of a variety of infections, many serious and life threatening. While aminoglycoside use declined due to the introduction of other antibiotic classes such as cephalosporins, fluoroquinolones, and carbapenems, there has been a resurgence of interest in the class as multidrug-resistant pathogens have spread globally. Furthermore, aminoglycosides are recommended as part of combination therapy for empiric treatment of certain difficult-to-treat infections. The development of semisynthetic aminoglycosides designed to overcome common aminoglycoside resistance mechanisms, and the shift to once-daily dosing, has spurred renewed interest in the class. Plazomicin is the first new aminoglycoside to be approved by the FDA in nearly 40 years, marking the successful start of a new campaign to rejuvenate the class.

Plazomicin: A Next-Generation Aminoglycoside

Plazomicin is a novel aminoglycoside antibiotic that binds to the bacterial 30S ribosomal subunit, thus inhibiting protein synthesis in a concentration-dependent manner. Plazomicin displays a broad spectrum of activity against aerobic gram-negative bacteria including extended-spectrum β-lactamase-producing Enterobacteriaceae, carbapenem-resistant Enterobacteriaceae, and organisms with aminoglycoside-modifying enzymes. In a large phase III clinical trial, plazomicin was shown to be noninferior to meropenem in the treatment of complicated urinary tract infections (cUTIs) with respect to the coprimary efficacy end points of the microbiologically modified intent-to-treat composite cure rate at day 5 (plazomicin 88% [168/191 subjects] vs meropenem 91.4% [180/197]) and at the test-of-cure visit (plazomicin 81.7% [156/191] vs meropenem 70.1% [138/197]). In a small phase III clinical trial, plazomicin was shown to be effective in the treatment of infections caused by carbapenem-resistant Enterobacteriaceae. It was associated with a lower all-cause mortality or significant disease-related complication rate (23.5% [4/17]) compared with colistin (50% [10/20]). The most common adverse reactions associated with plazomicin are decreased renal function, diarrhea, hypertension, headache, nausea, vomiting, and hypotension. As with other aminoglycosides, plazomicin may cause neuromuscular blockade, ototoxicity, and fetal harm in pregnant women. Due to limited efficacy and safety data, plazomicin is indicated for the treatment of cUTIs in adults with limited or no alternative treatment options, using a dosage regimen of 15 mg/kg intravenously every 24 hours for 4-7 days. Dosage reductions and therapeutic drug monitoring are warranted in patients with moderate or severe renal impairment. Plazomicin is not recommended in patients with severe renal impairment including those receiving renal replacement therapy. With the approval of plazomicin, clinicians now have an additional option for the treatment of adults with cUTIs, particularly those caused by multidrug-resistant gram-negative rods.