Comparison of the Pharmacokinetic Profiles of Ceftriaxone Used Alone and Combined with Danhong Injection in Old Rats.

BACKGROUND AND OBJECTIVES

Danhong injection is the most commonly prescribed adjuvant drug applied for the treatment of cardiovascular and cerebrovascular diseases in China. Ceftriaxone is usually prescribed along with Danhong injection to elderly patients with complications. However, the pharmacokinetic interactions between these two medications have not been investigated. The aim of this study was to investigate whether Danhong injection influences the pharmacokinetic profile of ceftriaxone in old rats when these two medications are used in combination.

METHODS

The animal experiment protocol was designed according to the clinical data. Ten-month-old male Sprague-Dawley (SD) rats were dosed with ceftriaxone through intravenous administration for 1 or 7 days in the presence or absence of Danhong injection. The combinations were divided into 1-day, 7-day, and 14-day combined-treatment groups in which Danhong injection was administered for 1, 7, or 14 days and ceftriaxone was given for 1, 7, or 7 days, respectively. The plasma concentration of ceftriaxone was determined by ultrahigh performance liquid chromatography coupled with triple-quadrupole mass spectrometry (UHPLC-TQ-MS) on a BEH C18 column with a mobile phase consisting of acetonitrile and 0.4% formic acid-water. The chromatographic method was validated and found to be simple, rapid, and stable.

RESULTS

Danhong injection significantly increased the plasma clearance of and decreased systemic exposure to ceftriaxone. In the 1-day combined-treatment group, the plasma clearance of ceftriaxone increased by 52.69%, and the area under the concentration-time curve (AUC) of ceftriaxone was decreased by 32.54% (P < 0.01). In the 7-day combined-treatment group, the rate of plasma clearance increased by 52.49% and the area under the concentration-time curve decreased by 31.15% (P < 0.01). For the 14-day combined-treatment group, the plasma clearance of ceftriaxone increased by 26.73%, and the area under the concentration-time curve decreased by 21.44% (P < 0.05).

CONCLUSIONS

In old male rats, systemic exposure to ceftriaxone decreased when used concomitantly with Danhong injection, which may be because Danhong injection increased the plasma clearance of ceftriaxone. Further investigations should be carried out to clarify the mechanism for the influence of Danhong injection on the pharmacokinetics of ceftriaxone.