Clinical translation of polymyxin-based combination therapy: Facts, challenges and future opportunities.

The emergence and spread of multidrug resistant Gram-negative bacteria has led to a resurgence in the clinical use of polymyxin antibiotics. However, the prevalence of polymyxin resistance is on the rise at an alarming rate, motivating the idea of combination therapy to sustain the revival of these "old" antibiotics. Although ample evidence in favor of combination therapy has emerged, it seems impracticable and confusing to find a promising combination from the diverse reports or gain adequate information on the efficacy and safety profile. With a stagnating discovery pipeline of novel antimicrobials, there is a clear need to fill the knowledge gaps in translating these basic research data to beneficial clinical practice. In this review, we examined the factors and ambiguities that stand as major hurdles in bringing polymyxin combination therapy to bedside care, highlighting the importance and urgency of incorporating translational research insights into areas of difficulty. We also discussed future research priorities that are essential to gather the necessary evidence and insights for promoting the best possible use of polymyxins in combination therapy.