Table 1.

Physiological antibiotic properties and implications for pharmacokinetics in critical illness

Pharmacokinetics	Lipid solubility
	Hydrophilic antibiotics	Lipophilic antibiotics
General	↓ Vd; ↑ Cmax, ↓ intracellular penetration; renal clearance	↑ Vd; ↓ Cmax; ↑ intracellular penetration; hepatic clearance
In critically ill	↑ Vd; ↑/↓ renal clearance; dependent on renal function and PB	Unchanged Vd; ↑/↓ hepatic clearance; dependent on hepatic function and PB
Examples	β-lactams, aminoglycosides, glycopeptides	Fluoroquinolones, macrolides, rifampicin, linezolid

C_max maximum plasma drug concentration, PB protein binding, V_d volume of distribution, ↑ and ↓ indicate increase and decrease, respectively