This is a general review telling about the polymyxin class of antibiotics. It has a chapter about PBT2 but only how it restores the antimicrobial efficacy of polymyxins, not how it works with penicillins, tetracyclines, etc. It is a free paper and Chapter 5 is written about PBT2

You will find the paper here: Antibiotics | Free Full-Text | Next-Generation Polymyxin Class of Antibiotics: A Ray of Hope Illuminating a Dark Road (mdpi.com)

Abstract:

Next-Generation Polymyxin Class of Antibiotics: A Ray of Hope Illuminating a Dark Road

Abdullah Tarık Aslan ^{1 2}, Murat Akova ³, David L Paterson ^{2 4}

Affiliations expand

• PMID: 36551367

DOI: 10.3390/antibiotics11121711

Abstract

Although new-generation antimicrobials, in particular β-lactam/β-lactamase inhibitors, have largely replaced polymyxins in carbapenem-resistant Gram-negative bacterial infections, polymyxins are still needed for carbapanem-resistant Acinetobacter baumannii infections and in settings where novel agents are not readily available. Despite their potent in vitro activity, the clinical utility of polymyxins is significantly limited by their pharmacokinetic properties and nephrotoxicity risk. There is significant interest, therefore, in developing next-generation polymyxins with activity against colistin-resistant strains and lower toxicity than existing polymyxins. In this review, we aim to present the antibacterial activity mechanisms, in vitro and in vivo efficacy data, and toxicity profiles of new-generation polymyxins, including SPR206, MRX-8, and QPX9003, as well as the general characteristics of old polymyxins. Considering the emergence of colistin-resistant strains particularly in endemic regions, the restoration of the antimicrobial activity of polymyxins via PBT2 is also described in this review.