Pharmacokinetics of ceftriaxone following intravenous administration of a 3 g dose.

The pharmacokinetic parameters of total (bound and unbound) and free (unbound) ceftriaxone in six healthy volunteers after intravenous injection of 39 were compared with low-dose data from a previous study. The dose-dependent behaviour of total drug was considerably more pronounced after the 3 gram dose. In contrast, total body clearance (C1FS = 258 ml/Min), renal clearance (C1FR = 170 ml/min) and volume of distribution (VFD (beta) = 168 1) of free (unbound) drug did not differ from the data reported earlier. There was no significant change in biological half-life (t1/2 (beta) = 7.8 h) or in the fraction excreted unchanged in urine (fu = 0.67).