Label: CEFPROZIL powder, for suspension

Microbiology

Cefprozil has in vitro activity against a broad range of gram-positive and gram-negative bacteria. The bactericidal action of cefprozil results from inhibition of cell-wall synthesis. Cefprozil has been shown to be active against most strains of the following microorganisms both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section.

The following in vitro data are available; however, their clinical significance is unknown. Cefprozil exhibits in vitro minimum inhibitory concentrations (MICs) of 8 mcg/mL or less against most (≥90%) strains of the following microorganisms; however, the safety and effectiveness of cefprozil in treating clinical infections due to these microorganisms have not been established in adequate and well-controlled clinical trials.

Aerobic gram-positive microorganisms:

        Enterococcus durans                                                    Staphylococcus warneri 
        Enterococcus faecalis                                                  Streptococcus agalactiae
        Listeria monocytogenes                                               Streptococci (Groups C,D,F, and G)
        Staphylococcus epidermidis                                        viridans group Streptococci
        Staphylococcus saprophyticus

        NOTE: Cefprozil is inactive against Enterococcus faecium.

Aerobic gram-negative microorganisms:

        Citrobacter diversus                                                    Proteus mirabilis 
        Escherichia coli                                                           Salmonella spp.
        Klebsiella pneumoniae                                                Shigella spp.
        Neisseria gonorrhoeae                                                Vibrio spp.
        (including β-lactamase-producing strains)

        NOTE: Cefprozil is inactive against most strains of Acinetobacter, Enterobacter, Morganella morganii, Proteus vulgaris, Providencia, Pseudomonas, and Serratia.

Anaerobic microorganisms:

Prevotella (Bacteroides) melaninogenicus                  Fusobacterium spp.
Clostridium difficile                                                     Peptostreptococcus spp.
Clostridium perfringens                                              Propionibacterium acnes

        NOTE: Most strains of the Bacteroides fragilis group are resistant to cefprozil.

Susceptibility Testing

For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: https://www.fda.gov/STIC.

General

Prescribing cefprozil in the absence of proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

In patients with known or suspected renal impairment (see DOSAGE AND ADMINISTRATION), careful clinical observation and appropriate laboratory studies should be done prior to and during therapy. The total daily dose of cefprozil should be reduced in these patients because high and/or prolonged plasma antibiotic concentrations can occur in such individuals from usual doses. Cephalosporins, including cefprozil, should be given with caution to patients receiving concurrent treatment with potent diuretics since these agents are suspected of adversely affecting renal function.

Prolonged use of cefprozil may result in the overgrowth of nonsusceptible organisms. Careful observation of the patient is essential. If superinfection occurs during therapy, appropriate measures should be taken.

Cefprozil should be prescribed with caution in individuals with a history of gastrointestinal disease particularly colitis.

Positive direct Coombs’ tests have been reported during treatment with cephalosporin antibiotics.

Information for Patients

Phenylketonurics: Cefprozil for oral suspension contains 8.4 mg of phenylalanine per 5 mL (1 teaspoonful) constituted suspension for both the 125 mg/5 mL and 250 mg/5 mL dosage forms.

Patients should be counseled that antibacterial drugs including cefprozil should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When cefprozil is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed.  Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by cefprozil or other antibacterial drugs in the future.

Diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued.  Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic.  If this occurs, patients should contact their physician as soon as possible.

Drug Interactions

Nephrotoxicity has been reported following concomitant administration of aminoglycoside antibiotics and cephalosporin antibiotics. Concomitant administration of probenecid doubled the AUC for cefprozil.

The bioavailability of the capsule formulation of cefprozil was not affected when administered 5 minutes following an antacid.

Drug/laboratory Test Interactions

Cephalosporin antibiotics may produce a false positive reaction for glucose in the urine with copper reduction tests (Benedict’s or Fehling’s solution or with Clinitest® tablets1), but not with enzyme-based tests for glycosuria (e.g., Clinistix®). A false negative reaction may occur in the ferricyanide test for blood glucose. The presence of cefprozil in the blood does not interfere with the assay of plasma or urine creatinine by the alkaline picrate method.

1 Clinitest ® and Clinistix ® are registered trademarks of Bayer Healthcare LLC.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Long term in vivo studies have not been performed to evaluate the carcinogenic potential of cefprozil.

Cefprozil was not found to be mutagenic in either the Ames Salmonella or E. coli WP2 urvA reversion assays or the Chinese hamster ovary cell HGPRT forward gene mutation assay and it did not induce chromosomal abnormalities in Chinese hamster ovary cells or unscheduled DNA synthesis in rat hepatocytes in vitro. Chromosomal aberrations were not observed in bone marrow cells from rats dosed orally with over 30 times the highest  recommended human dose based upon mg/m2.

Impairment of fertility was not observed in male or female rats given oral doses of cefprozil up to 18.5 times the highest recommended human dose based upon mg/m2.

Pregnancy

Labor and Delivery

Cefprozil has not been studied for use during labor and delivery. Treatment should only be given if clearly needed.

Nursing Mothers

Small amounts of cefprozil (<0.3% of dose) have been detected in human milk following administration of a single 1 gram dose to lactating women. The average levels over 24 hours ranged from 0.25 to 3.3 mcg/mL. Caution should be exercised when cefprozil is administered to a nursing woman, since the effect of cefprozil on nursing infants is unknown.

Pediatric Use

(See INDICATIONS AND USAGE and DOSAGE AND ADMINISTRATION.)

The safety and effectiveness of cefprozil in the treatment of otitis media have been established in the age groups 6 months to 12 years. Use of cefprozil for the treatment of otitis media is supported by evidence from adequate and well-controlled studies of cefprozil in pediatric patients. (See CLINICAL STUDIES.)

The safety and effectiveness of cefprozil in the treatment of pharyngitis/tonsillitis or uncomplicated skin and skin-structure infections have been established in the age groups 2 to 12 years. Use of cefprozil for the treatment of these infections is supported by evidence from adequate and well-controlled studies of cefprozil in pediatric patients.

The safety and effectiveness of cefprozil in the treatment of acute sinusitis have been established in the age groups 6 months to 12 years. Use of cefprozil in these age groups is supported by evidence from adequate and well-controlled studies of cefprozil in adults.

Safety and effectiveness in pediatric patients below the age of 6 months have not been established for the treatment of otitis media or acute sinusitis, or below the age of 2 years for the treatment of pharyngitis/tonsillitis or uncomplicated skin and skin-structure infections. However, accumulation of other cephalosporin antibiotics in newborn infants (resulting from prolonged drug half-life in this age group) has been reported.

Geriatric Use

Of the more than 4500 adults treated with cefprozil in clinical studies, 14% were 65 years and older, while 5% were 75 years and older.  When geriatric patients received the usual recommended adult doses, their clinical efficacy and safety were comparable to clinical efficacy and safety in nongeriatric adult patients. Other reported clinical experience has not identified differences in responses between elderly and younger patients, but greater sensitivity of some older individuals to the effects of cefprozil cannot be excluded (see CLINICAL PHARMACOLOGY).

Cefprozil is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection and it may be useful to monitor renal function. See DOSAGE AND ADMINISTRATION for dosing recommendations for patients with impaired renal function.

Cephalosporin class paragraph

In addition to the adverse reactions listed above which have been observed in patients treated with cefprozil, the following adverse reactions and altered laboratory tests have been reported for cephalosporin-class antibiotics:

Aplastic anemia, hemolytic anemia, hemorrhage, renal dysfunction, toxic epidermal necrolysis, toxic nephropathy, prolonged prothrombin time, positive Coombs’ test, elevated LDH, pancytopenia, neutropenia, agranulocytosis.

Several cephalosporins have been implicated in triggering seizures, particularly in patients with renal impairment, when the dosage was not reduced. (See DOSAGE AND ADMINISTRATION and OVERDOSAGE.) If seizures associated with drug therapy occur, the drug should be discontinued. Anticonvulsant therapy can be given if clinically indicated.

Renal Impairment

Cefprozil may be administered to patients with impaired renal function. The following dosage schedule should be used.

Hepatic Impairment

No dosage adjustment is necessary for patients with impaired hepatic function.

Study One:

In a controlled clinical study of acute otitis media performed in the United States where significant rates of β-lactamase-producing organisms were found, cefprozil was compared to an oral antimicrobial agent that contained a specific β-lactamase inhibitor. In this study, using very strict evaluability criteria and microbiologic and clinical response criteria at the 10 to 16 days post-therapy follow-up, the following presumptive bacterial eradication/clinical cure outcomes (i.e., clinical success) and safety results were obtained:

SAFETY:

The incidences of adverse events, primarily diarrhea and rash*, were clinically and statistically significantly higher in the control arm versus the cefprozil arm.

Study Two:

In a controlled clinical study of acute otitis media performed in Europe, cefprozil was compared to an oral antimicrobial agent that contained a specific β-lactamase inhibitor. As expected in a European population, this study population had a lower incidence of β-lactamase-producing organisms than usually seen in U.S. trials. In this study, using very strict evaluability criteria and microbiologic and clinical response criteria at the 10 to 16 days post-therapy follow-up, the following presumptive bacterial eradication/clinical cure outcomes (i.e., clinical success) were obtained:

SAFETY:

The incidence of adverse events in the cefprozil arm was comparable to the incidence of adverse events in the control arm (agent that contained a specific β-lactamase inhibitor).