Pharmacokinetic Data Are Predictive of In Vivo Efficacy for Cefixime and Ceftriaxone against Susceptible and Resistant Neisseria gonorrhoeae Strains in the Gonorrhea Mouse Model

• There is a pressing need for drug development for gonorrhea. Here we describe pharmacokinetics/pharmacodynamics (PK/PD) analysis of extended-spectrum cephalosporins (ESC) against drug-susceptible and drug-resistant gonococcal strains in a murine genital tract infection model. PK determined in uninfected mice displayed a clear dose response in plasma levels following single doses of ceftriaxone (CRO) (intraperitoneal) or cefixime (CFM) (oral). The observed doses required for efficacy against ESCS strain FA1090 were 5 mg/kg (CRO) and 12 mg/kg (CFM); these doses had estimated therapeutic times (time of free drug above the MIC, fTMIC) of 24 h and 37 h, respectively. No single dose of CRO or CFM was effective against the ESCR strain H041. However, fractionation (TIDq8h) of a 120 mg/kg dose of CRO resulted in estimated therapeutic times in the range of 23 h and cleared H041 infection in a majority (90%) of mice, comparable to gentamicin. In contrast, multiple CFM doses of 120 or 300 mg/kg administered TIDq8h cleared infection in ≤ 50% of mice with therapeutic times estimated from single-dose PK data, of 13 and 27 h, respectively. This study reveals a clear relationship between plasma ESC levels and bacterial clearance rates in the gonorrhea mouse model. The PK/PD relationships in mice reflected that observed in humans with in vivo efficacy against an ESCS strain requiring doses that yielded an fTMIC in excess of 20-24 h. PK data also accurately predicted the failure of single doses of ESCs against an ESCR strain and were useful in designing effective dosing regimens.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Farmaceutiska vetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Pharmaceutical Sciences (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Microbiology in the medical area (hsv//eng)

Nyckelord

antibiotic resistance

cefixime

ceftriaxone

clearance

gonorrhea

mouse model

pharmacokinetics

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)