Cefpoderm ® (cefpodoxime proxetil tablets)

Cefpodoxime Proxetil Chemical Structure:

Cefpodoxime proxetil is a prodrug; its active metabolite is cefpodoxime. All doses of Cefpoderm (cefpodoxime proxetil tablets) are expressed in terms of the active cefpodoxime moiety. Cefpoderm is available as:

100 mg Tablet, each yellow, elliptical, scored tablet contains cefpodoxime proxetil equivalent to 100 mg of cefpodoxime.

200 mg Tablet, each orange, oblong, tablet contains cefpodoxime proxetil equivalent to 200 mg of cefpodoxime.

Dose range: The dose range of Cefpoderm is 5-10 mg/kg (2.3-4.5 mg/lb) body weight, administered orally, once a day.

The dose may be given with or without food. The determination of dosage for any particular patient must take into consideration such factors as the severity and nature of the infection, the susceptibility of the causative organisms, and the integrity of the patient's host-defense mechanisms. Obtain a sample of the pathogenic organism for culture and sensitivity testing prior to beginning antimicrobial therapy. Once results become available, continue with appropriate therapy.

Duration: Cefpoderm should be administered once daily for 5-7 days or for 2-3 days beyond the cessation of clinical signs, up to a maximum of 28 days. Treatment of acute infections should not be continued for more than 3-4 days if no response to therapy is seen.

Dosing Charts: For daily oral administration of Cefpoderm at 5 mg/kg (Table 1) and 10 mg/kg (Table 2).

Pharmacokinetics/Pharmacodynamics:

Cefpodoxime proxetil is a prodrug that is absorbed from and de-esterified in the gastrointestinal tract to its active metabolite, cefpodoxime. Following oral administration to fasting Beagles, oral bioavailability was 63.1 ± 5.3%.

Figure 1. Canine Plasma Concentration of Cefpodoxime After a Single Oral Dose of 10 mg/kg Cefpodoxime Proxetil Tablets

Figure 1

Cefpodoxime is distributed in the body with an apparent volume of distribution of 151 ± 27 mL/kg. Like other β-lactam antibiotics, cefpodoxime is eliminated from the body primarily in the urine, with an apparent elimination half-life of approximately 5-6 hours after oral administration. This is similar to the 4.7 hour apparent elimination half-life observed after intravenous dosing. Following intravenous administration of 10 mg/kg, the average total body clearance (Cl_B) was 22.7 ± 4.19 mL/hr/kg.

Microbiology: Like other β-lactam antibiotics, cefpodoxime exerts its inhibitory effect by interfering with bacterial cell wall synthesis. This interference is primarily due to its covalently binding to the penicillin-binding proteins (PBPs) (i.e. transpeptidase and/or carboxypeptidase), which are essential for synthesis of the bacterial cell wall. Therefore, cefpodoxime is bactericidal. Cefpodoxime is stable in the presence of many common β-lactamase enzymes. As a result, many organisms resistant to other β-lactam antibiotics (penicillins and some cephalosporins) due to the production of β-lactamases may be susceptible to cefpodoxime.

Cefpodoxime has a broad spectrum of clinically useful antibacterial activity that includes staphylococci, streptococci, and Gram-negative species (including Pasteurella, Escherichia, and Proteus). The compound is not active against most obligate anaerobes, Pseudomonas spp., or enterococci. The minimum inhibitory concentrations (MICs) for cefpodoxime against Gram-positive and Gram-negative pathogens isolated from canine skin infections (wounds and abscesses) in a 2002 U.S. field study are presented in Table 5. All MICs were determined in accordance with the National Committee for Clinical Laboratory Standards (NCCLS). Appropriate quality control (QC) ranges for in vitro susceptibility testing are presented in Table 6.

EFFECTIVENESS:

The clinical effectiveness of cefpodoxime proxetil tablets was established in a multi-location (23 site) field study. In this study, 216 dogs with infected wounds or abscesses were treated with either cefpodoxime proxetil (n=118) once daily at 5 mg/kg (2.3 mg/lb) body weight or with an active control antibiotic (n=98) administered twice daily for 5-7 days. In this study, cefpodoxime proxetil was considered noninferior to the active control (88.7% versus 88.4% respectively) in the treatment of canine skin infections (wounds and abscesses) caused by susceptible strains of Staphylococcus pseudintermedius, Staphylococcus aureus, Streptococcus canis (group G, β hemolytic), Escherichia coli, Pasteurella multocida, and Proteus mirabilis.