Table 2. The PTA for the different colistin regimens in critically ill patients according to kidney function (creatinine clearance) at steady state with targets of fAUC24/MIC ≥25 (for efficacy) and trough concentration ≥3.3 µg/mL (risk of acute kidney injury).

Creatinine clearance (mL/min)	Dosage regimens		PTA (%)								Trough concentration ≥3.3 µg/mL (%)
			Colistin MIC (µg/mL) against CRAB isolates
	Loading dose	Maintenance dose	0.125	0.25	0.5	1	2	4	8	16
0 – 9	300 mg	100 mg q24h	100	100	100	99	95	82	56	28	69
		100 mg q12h	100	100	100	100	100	97	87	66	83
		150 mg q12h	100	100	100	100	100	97	86	66	83
		150 mg q24h	100	100	100	99	96	81	55	28	70
		180 mg q24h	100	100	100	99	96	81	56	28	70
10 – 25	300 mg	100 mg q12h	100	100	100	100	98	92	75	49	90
		150 mg q12h	100	100	100	100	98	90	73	49	89
		150 mg q24h	100	100	100	97	88	66	37	14	53
		180 mg q24h	100	100	100	97	88	65	36	14	52
26 – 50	300 mg	100 mg q12h	100	100	99	97	91	77	54	29	76
		150 mg q12h	100	100	99	98	92	77	54	29	76
		150 mg q24h	100	99	97	89	70	43	19	6	32
		180 mg q24h	100	99	97	89	71	43	20	6	32
51 – 90	300 mg	150 mg q24h	98	95	87	71	46	22	7	2	15
		150 mg q12h	99	98	95	89	75	54	32	14	54
		150 mg q8h	100	99	98	94	86	71	51	30	73
		180 mg q12h	100	99	96	89	75	54	31	14	55
		180 mg q8h	100	99	98	94	86	72	51	30	74
91 – 130	300 mg	150 mg q12h	98	95	88	75	56	34	16	6	34
		150 mg q8h	99	97	93	84	71	52	32	16	54
		180 mg q12h	98	95	87	75	55	33	16	6	35
		180 mg q8h	99	97	93	85	71	51	31	14	54

Color codes Strongly recommended dose based on ≥90% PTA or ≥90% CFR.

Moderately recommended dose based on 80 - 89% PTA or 80 - 89% CFR.

PTA, probability of target attainment; AUC, area under the curve; MIC, minimum inhibitory concentration; CRAB, carbapenem-resistant Acinetobacter baumannii; CFR, cumulative fraction of response.