Ceftazidime pharmacokinetics in dogs after intravenous injection and delivered with the RxActuator Mini-Infuser infusion pump

OBJECTIVE

To test the feasibility of an SC mini-infusion pump to deliver ceftazidime in dogs and produce plasma concentrations sufficient to reach a therapeutic target for 48 hours.

SETTING

University research laboratory.

ANIMALS

Six healthy Beagle dogs.

INTERVENTIONS

Ceftazidime was administered by 2 routes to 6 healthy Beagle dogs. The first route was an IV bolus injection into a cephalic vein at a dose of 25 mg/kg. Blood samples were collected for 8 hours following injection. The second route was a SC infusion for 48 hours using the RxActuator Mini-Infuser wearable SC constant rate infusion pump. Blood samples were collected for 58 hours following application of the pump. All plasma samples were analyzed by high-pressure liquid chromatography and subject to pharmacokinetic analysis.

MAIN RESULTS

After the IV bolus injection, there was rapid distribution and elimination. The elimination half-life was 0.95 hours, and the clearance was rapid at 0.176 ml/h/kg. After the 48-hour SC infusion, the half-life was slightly shorter, and the clearance was higher. The percent bioavailability from the SC infusion was approximately 72%. The SC infusion maintained plasma concentration near our target of 8 μg/ml for most of the dose interval but slightly lower after 24 hours. The concentrations below the target were attributed to slight drug loss, less than 100% bioavailability, and faster clearance from SC administration.

CONCLUSIONS

This study demonstrated the successful application of the RxActuator Mini-Infuser wearable SC constant rate infusion pump for delivering an antimicrobial needed for serious, and sometimes resistant, infections in dogs.

Human glucose-dependent insulinotropic polypeptide (GIP) is an antimicrobial adjuvant re-sensitising multidrug-resistant Gram-negative bacteria

Increasing antibiotic resistance in Gram-negative bacteria has mandated the development of both novel antibiotics and alternative therapeutic strategies. Evidence of interplay between several gastrointestinal peptides and the gut microbiota led us to investigate potential and broad-spectrum roles for the incretin hormone, human glucose-dependent insulinotropic polypeptide (GIP) against the Enterobacteriaceae bacteria, Escherichia coli and Erwinia amylovora. GIP had a potent disruptive action on drug efflux pumps of the multidrug resistant bacteria E. coli TG1 and E. amylovora 1189 strains. The effect was comparable to bacterial mutants lacking the inner and outer membrane efflux pump factor proteins AcrB and TolC. While GIP was devoid of direct antimicrobial activity, it has a potent membrane depolarizing effect, and at low concentrations, it significantly potentiated the activity of eight antibiotics and bile salt by reducing MICs by 4-8-fold in E. coli TG1 and 4-20-fold in E. amylovora 1189. GIP can thus be regarded as an antimicrobial adjuvant with potential for augmenting the available antibiotic arsenal.