Pharmacokinetics and tolerability of intravenous cefotetan disodium for injection in healthy Chinese volunteers: A randomized, open-label, single- and multiple-dose study

Background: Cefotetan disodium for injection is a semisynthetic cephamycin Antibiotic that exerts its bactericidal effects by inhibition of cell-wall synthesis. Despite being widely used in the treatment of various infections, little information is available on the pharmacokinetic properties of cefotetan disodium in Chinese subjects.

Objectives: This study evaluated the pharmacokinetics of single and multiple intravenous doses of a generic formulation of cefotetan disodium in healthy Chinese volunteers. The effect of sex on the pharmacokinetics of cefotetan disodium was evaluated as a secondary objective.

Methods: In this open-label, dose-escalating study, subjects were randomized to receive a single dose of cefotetan disodium 0.5, 1.0, or 2.0 g administered as a 1-hour intravenous infusion. Those allocated to the 1.0-g dose continued into the multiple-dose phase, in which they received 1.0 g BID for 7 consecutive days. During the single-dose phase, blood samples were collected at regular intervals from 0 to 15 hours after drug administration and were analyzed using a validated HPLC method. During the multiple-dose phase, blood samples were obtained before drug administration on days 5, 6, and 7 to determine the C(min) at steady state; on day 7, blood samples were also collected from 0 to 15 hours after drug administration. Tolerability was assessed based on physical examinations, vital signs, laboratory tests (hematology, biochemistry, hepatic and renal function, and urinalysis), and subject interviews.

Results: Three groups, each consisting of 5 men and 5 women, were enrolled in the single-dose phase. The mean (SD) age of subjects was 23.2 (2.2) years (range, 19-30 years). Their mean weight was 57.0 (6.3) kg (range, 46.4-72.0 kg), and their mean height was 1.66 (0.08) m (range, 1.48-1.81 m). After intravenous administration of single doses of 0.5, 1.0, and 2.0 g, the cefotetan disodium C(max) was 35.01 (6.98), 76.67 (10.52), and 154.33 (27.17) mg/L, respectively; the AUC₀₋₁₅(h) was 145.35 (18.36), 307.45 (33.07), and 746.09 (103.07) mg · h/L; the AUC₀₋(∞) was 171.51 (20.61), 347.25 (44.20), and 843.84 (131.13) mg · h/L; the t(1/2) was 5.80 (1.29), 4.91 (1.15), and 5.04 (1.26) hours; the CL was 2.96 (0.41), 2.92 (0.39), and 2.42 (0.39) L/h; and the V(d) was 24.55 (5.19), 20.37 (3.66), and 17.30 (3.52) L. After administration of multiple doses, the cefotetan disodium C(max,ss) was 80.53 (10.04) mg/L; the C(mix,ss) was 11.00 (4.04) mg/L; the AUC(ss) was 347.92 (50.04) mg · h/L; the steady-state plasma concentration was 28.99 (4.17) mg/L; the t(1/2) was 6.24 (2.52) hours; the CL was 2.32 (0.64) L/h; and the Vd was 19.19 (4.58) L. No significant differences in pharmacokinetic parameters were noted by sex in the multiple-dose phase. Cefotetan disodium appeared to be well tolerated.

Conclusions: In these healthy Chinese subjects, the cefotetan disodium AUC and C(max) increased in a dose-proportional manner, whereas the t(1/2) was independent of dose. The pharmacokinetic properties of cefotetan disodium were linear at doses of 0.5 to 2.0 g. After multiple doses, the pharmacokinetic parameters of cefotetan disodium were consistent with those after single doses. At the doses studied, cefotetan disodium appeared to be well tolerated in these healthy volunteers.