AUGMENTIN Powder for suspension / Film coated-tablet Ref.[10549] Active ingredients: Amoxicillin Clavulanic acid

Mean amoxicillin and clavulanate potassium pharmacokinetic parameters in normal adults following administration of AUGMENTIN Tablets are shown in Table 3 and following administration of AUGMENTIN Powder for Oral Suspension and Chewable Tablets are shown in Table 4.

Table 3. Mean (± S.D.) Amoxicillin and Clavulanate Potassium Pharmacokinetic Parameters^a,b with AUGMENTIN Tablet:

^a Mean (± standard deviation) values of 14 normal adults (N=15 for clavulanate potassium in the low-dose regimens). Peak concentrations occured approximately 1.5 hours after the dose.
^b Amoxicillin/clavulanate potassium administered at the start of a light meal.

Table 4. Mean (± S.D.) Amoxicillin and Clavulanate Potassium Pharmacokinetic Parameters^a,b with AUGMENTIN Powder for Oral Suspension and Chewable tablets:

^a Mean (± standard deviation) values of 28 normal adults. Peak concentrations occured approximately 1 hours after the dose.
^b Amoxicillin/clavulanate potassium administered at the start of a light meal.

Oral administration of 5 mL of 250 mg/5 mL suspension of AUGMENTIN or the equivalent dose of 10 mL of 125 mg/5 mL suspension of AUGMENTIN provides average peak serum concentrations approximately 1 hour after dosing of 6.9 mcg/mL for amoxicillin and 1.6 mcg/mL for clavulanic acid. The areas under the serum concentration curves obtained during the first 4 hours after dosing were 12.6 mcg*h/mL for amoxicillin and 2.9 mcg*h/mL for clavulanic acid when 5 mL of 250 mg/5 mL suspension of AUGMENTIN or equivalent dose of 10 mL of 125 mg/5 mL suspension of AUGMENTIN were administered to normal adults. One 250 mg chewable tablet of AUGMENTIN or two 125 mg chewable tablets of AUGMENTIN are equivalent to 5 mL of 250 mg/5 mL suspension of AUGMENTIN and provide similar serum concentrations of amoxicillin and clavulanic acid.

Amoxicillin serum concentrations achieved with AUGMENTIN are similar to those produced by the oral administration of equivalent doses of amoxicillin alone. Time above the minimum inhibitory concentration of 1 mcg/mL for amoxicillin has been shown to be similar after corresponding every 12 hour and every 8 hour dosing regimens of AUGMENTIN in adults and children.

Absorption

Dosing in the fasted or fed state has minimal effect on the pharmacokinetics of amoxicillin. While AUGMENTIN can be given without regard to meals, absorption of clavulanate potassium when taken with food is greater relative to the fasted state. In one study, the relative bioavailability of clavulanate was reduced when AUGMENTIN was dosed at 30 and 150 minutes after the start of a high‑fat breakfast.

Distribution

Neither component in AUGMENTIN is highly protein‑bound; clavulanic acid is approximately 25% bound to human serum and amoxicillin approximately 18% bound.

Amoxicillin diffuses readily into most body tissues and fluids with the exception of the brain and spinal fluid.

Two hours after oral administration of a single 35 mg/kg dose of suspension of AUGMENTIN to fasting children, average concentrations of 3 mcg/mL of amoxicillin and 0.5 mcg/mL of clavulanic acid were detected in middle ear effusions.

Metabolism and Excretion

The half‑life of amoxicillin after the oral administration of AUGMENTIN is 1.3 hours and that of clavulanic acid is 1 hour.

Approximately 50% to 70% of the amoxicillin and approximately 25% to 40% of the clavulanic acid are excreted unchanged in urine during the first 6 hours after administration of a single 250 mg or 500 mg tablet of AUGMENTIN.

Amoxicillin is a semisynthetic antibiotic with in vitro bactericidal activity against Gram-positive and Gram-negative bacteria. Amoxicillin is, however, susceptible to degradation by beta-lactamases, and therefore, the spectrum of activity does not include organisms which produce these enzymes. Clavulanic acid is a beta-lactam, structurally related to the penicillins, which possesses the ability to inactivate some beta-lactamase enzymes commonly found in microorganisms resistant to penicillins and cephalosporins. In particular, it has good activity against the clinically important plasmid-mediated beta-lactamases frequently responsible for transferred drug resistance.

The formulation of amoxicillin and clavulanic acid in AUGMENTIN protects amoxicillin from degradation by some beta-lactamase enzymes and extends the antibiotic spectrum of amoxicillin to include many bacteria normally resistant to amoxicillin.

Amoxicillin/clavulanic acid has been shown to be active against most isolates of the following bacteria, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section.

Gram-positive bacteria:

Staphylococcus aureus

Gram-negative bacteria:

Enterobacter species
Escherichia coli
Haemophilus influenzae
Klebsiella species
Moraxella catarrhalis

The following in vitro data are available, but their clinical significance is unknown. At least 90 percent of the following bacteria exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptible breakpoint for amoxicillin/clavulanic acid. However, the efficacy of amoxicillin/clavulanic acid in treating clinical infections due to these bacteria has not been established in adequate and well-controlled clinical trials.

Gram-positive bacteria:

Enterococcus faecalis
Staphylococcus epidermidis
Staphylococcus saprophyticus
Streptococcus pneumoniae
Streptococcus pyogenes
Viridans group Streptococcus

Gram-negative Bacteria:

Eikenellacorrodens
Proteus mirabilis

Anaerobic Bacteria:

Bacteroidesspecies including Bacteroides fragilis
Fusobacterium species
Peptostreptococcus species

Susceptibility Test Methods

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.

Long‑term studies in animals have not been performed to evaluate carcinogenic potential.

AUGMENTIN (4:1 ratio formulation of amoxicillin:clavulanate) was non-mutagenic in the Ames bacterial mutation assay, and the yeast gene conversion assay. AUGMENTIN was weakly positive in the mouse lymphoma assay, but the trend toward increased mutation frequencies in this assay occurred at doses that were also associated with decreased cell survival. AUGMENTIN was negative in the mouse micronucleus test, and in the dominant lethal assay in mice. Potassium clavulanate alone was tested in the Ames bacterial mutation assay and in the mouse micronucleus test, and was negative in each of these assays.

AUGMENTIN (2:1 ratio formulation of amoxicillin:clavulanate) at oral doses of up to 1,200 mg/kg/day was found to have no effect on fertility and reproductive performance in rats. Based on body surface area, this dose of amoxicillin is approximately 4 times the maximum recommended adult human oral dose (875 mg every 12 hours). For clavulanate, the dose multiple is approximately 9 times higher than the maximum recommended adult human oral dose (125 mg every 8 hours), also based on body surface area.

14.1 Lower Respiratory Tract and Complicated Urinary Tract Infections

Data from 2 pivotal trials in 1,191 patients treated for either lower respiratory tract infections or complicated urinary tract infections compared a regimen of 875 mg tablets of AUGMENTIN every 12 hours to 500 mg tablets of AUGMENTIN dosed every 8 hours (584 and 607 patients, respectively). Comparable efficacy was demonstrated between the every 12 hours and every 8 hours dosing regimens. There was no significant difference in the percentage of adverse events in each group. The most frequently reported adverse event was diarrhea; incidence rates were similar for the 875 mg every 12 hours and 500 mg every 8 hours dosing regimens (15% and 14%, respectively); however, there was a statistically significant difference (p<0.05) in rates of severe diarrhea or withdrawals with diarrhea between the regimens: 1% for 875 mg every 12 hours regimen versus 2% for the 500 mg every 8 hours regimen.

In one of these pivotal trials, patients with either pyelonephritis (n=361) or a complicated urinary tract infection (i.e., patients with abnormalities of the urinary tract that predispose to relapse of bacteriuria following eradication, n=268) were randomized (1:1) to receive either 875 mg tablets of AUGMENTIN every 12 hours (n=308) or 500 mg tablets of AUGMENTIN every 8 hours (n=321).

The number of bacteriologically evaluable patients was comparable between the two dosing regimens. AUGMENTIN produced comparable bacteriological success rates in patients assessed 2 to 4 days immediately following end of therapy. The bacteriologic efficacy rates were comparable at one of the follow‑up visits (5 to 9 days post‑therapy) and at a late post‑therapy visit (in the majority of cases, this was 2 to 4 weeks post-therapy), as seen in Table 7.

Table 7. Bacteriologic efficacy rates for AUGMENTIN:

As noted before, though there was no significant difference in the percentage of adverse events in each group, there was a statistically significant difference in rates of severe diarrhea or withdrawals with diarrhea between the regimens.

14.2 Acute Bacterial Otitis Media and Diarrhea in Pediatric Patients

One US/Canadian clinical trial was conducted which compared 45/6.4 mg/kg/day (divided every 12 hours) of AUGMENTIN for 10 days versus 40/10 mg/kg/day (divided every 8 hours) of AUGMENTIN for 10 days in the treatment of acute otitis media. Only the suspension formulations were used in this trial. A total of 575 pediatric patients (aged 2 months to 12 years) were enrolled, with an even distribution among the 2 treatment groups and a comparable number of patients were evaluable (i.e., 84%) per treatment group. Otitis media‑specific criteria were required for eligibility and a strong correlation was found at the end of therapy and follow‑up between these criteria and physician assessment of clinical response. The clinical efficacy rates at the end of therapy visit (defined as 2‑4 days after the completion of therapy) and at the follow‑up visit (defined as 22‑28 days post‑completion of therapy) were comparable for the 2 treatment groups, with the following cure rates obtained for the evaluable patients: At end of therapy, 87% (n=265) and 82% (n=260) for 45 mg/kg/day every 12 hours and 40 mg/kg/day every 8 hours, respectively. At follow‑up, 67% (n=249) and 69% (n=243) for 45 mg/kg/day every 12 hours and 40 mg/kg/day every 8 hours, respectively.

Diarrhea was defined as either: (a) 3 or more watery or 4 or more loose/watery stools in 1 day; OR (b) 2 watery stools per day or 3 loose/watery stools per day for 2 consecutive days. The incidence of diarrhea was significantly lower in patients who received the every 12 hours regimen compared to patients who received the every 8 hours regimen (14% and 34%, respectively). In addition, the number of patients with either severe diarrhea or who were withdrawn with diarrhea was significantly lower in the every 12 hours treatment group (3% and 8% for the every 12 hours/10 day and every 8 hours/10 day, respectively). In the every 12 hours treatment group, 3 patients (1%) were withdrawn with an allergic reaction, while 1 patient in the every 8 hours group was withdrawn for this reason. The number of patients with a candidal infection of the diaper area was 4% and 6% for the every 12 hours and every 8 hours groups, respectively.

It is not known if the finding of a statistically significant reduction in diarrhea with the oral suspensions dosed every 12 hours, versus suspensions dosed every 8 hours, can be extrapolated to the chewable tablets. The presence of mannitol in the chewable tablets may contribute to a different diarrhea profile. The every 12 hour oral suspensions (200 mg/5 mL and 400 mg/5 mL) are sweetened with aspartame.