Good tolerability of high dose colistin-based therapy in patients with haematological malignancies

Purpose Colistin is usually the only drug fully active against multi-drug resistant Gram-negative bacteria, but its nephrotoxicity might limit its use. Recent pharmacokinetic/pharmacodynamic data suggest that high dose of colistin, preceded by a loading dose, are needed to maximize its antibacterial effect. The aim of this study was to determine the safety of high doses colistin, in haematology population. Methods A retrospective review of haematology patients who received high dose colistin-based therapy in years 2011-2016 was performed. Nephrotoxicity was assessed using RIFLE criteria. Results Thirty patients who received 38 courses of colistin were included in the study. Colistin was always administered together with other antibiotics. Colistin was well tolerated, with one case of neurological toxicity and one of cutaneous reaction. There were 22 (58%) treatment cycles without any nephrotoxicity, even though during 16 of these cycles other nephrotoxic drugs were administered. Severe (injury or failure) renal toxicity occurred during 6 (16%) treatment courses, requiring colistin discontinuation in 2 patients and colistin dose reduction in 1. Poorer renal function at baseline and younger age were the only variables associated with increased renal toxicity (p = 0.011 and p = 0.031, respectively). Overall mortality was 18% (7/38) and 29% (11/38) at 7 and 30 days after the treatment onset. Conclusions In adult haematology population, high dose colistin therapy is safe and efficacious, despite high frequency of concomitant nephrotoxic treatment.