General Information

Augmentin is a combination of Amoxicillin and clavulanic acid, both of which are antibiotics used to treat a wide variety of bacterial infections. It works by stopping the growth of bacteria. This antibiotic treats only bacterial infections. 

Augmentin is indicated in the treatment of infections caused by susceptible strains of the designated organisms in the conditions listed below:

• Lower Respiratory Tract Infections – caused by β-lactamase–producing strains of H. influenzae and M. catarrhalis.
• Otitis Media – caused by β-lactamase–producing strains of H. influenzae and M. catarrhalis.
• Sinusitis – caused by β-lactamase–producing strains of H. influenzae and M. catarrhalis.
• Skin and Skin Structure Infections – caused by β-lactamase–producing strains of S. aureus, E. coli, and Klebsiella spp.
• Urinary Tract Infections – caused by β-lactamase–producing strains of E. coli, Klebsiella spp. and Enterobacter spp.

Augmentin is supplied as a powder for oral suspension and tablets for oral administration. The recommended dosing/administration is as follows:

Neonates and infants aged <12 weeks (3 months):

• Due to incompletely developed renal function affecting elimination of amoxicillin in this age group, the recommended dose of Augmentin is 30 mg/kg/day divided q12h, based on the amoxicillin component. Clavulanate elimination is unaltered in this age group. Experience with the 200 mg/5 mL formulation in this age group is limited and, thus, use of the 125 mg/5 mL oral suspension is recommended.

Patients aged 12 weeks (3 months) and older:

   Infections:                                                        Dosing Regimen:

Pediatric Patients Weighing 40 kg and More:

• Should be dosed according to the following adult recommendations: The usual adult dose is one 500-mg tablet of Augmentin every 12 hours or one 250-mg tablet of Augmentin every 8 hours. For more severe infections and infections of the respiratory tract, the dose should be one 875-mg tablet of Augmentin every 12 hours or one 500-mg tablet of Augmentin every 8 hours. Among adults treated with 875 mg every 12 hours, significantly fewer experienced severe diarrhea or withdrawals with diarrhea versus adults treated with 500 mg every 8 hours. 

Adults:

• Adults who have difficulty swallowing may be given the 125 mg/5 mL or 250 mg/5 mL suspension in place of the 500-mg tablet. The 200 mg/5 mL suspension or the 400 mg/5 mL suspension may be used in place of the 875-mg tablet.

Mechanism of Action

Augmentin is an oral antibacterial combination consisting of the semisynthetic antibiotic amoxicillin and the β-lactamase inhibitor, clavulanate potassium (the potassium salt of clavulanic acid). Augmentin has broad spectrum of bactericidal activity against many gram-positive and gram-negative microorganisms. Amoxicillin is, however, susceptible to degradation by β-lactamases, and therefore, the spectrum of activity does not include organisms which produce these enzymes. Clavulanic acid is a β-lactam, structurally related to the penicillins, which possesses the ability to inactivate a wide range of β-lactamase enzymes commonly found in microorganisms resistant to penicillins and cephalosporins. In particular, it has good activity against the clinically important plasmid-mediated β-lactamases frequently responsible for transferred drug resistance.

Side Effects

Adverse effects associated with the use of Augmentin may include, but are not limited to, the following: 

• diarrhea/loose stools
• nausea
• skin rashes and urticaria
• vomiting
• vaginitis

Clinical Trial Results

The FDA approval of Augmentin was based in part on the following clinical trials:

A clinical trial was conducted in pediatric patients aged 2 months to 12 years (n=575) and compared 45/6.4 mg/kg/day (divided q12h) of Augmentin for 10 days versus 40/10 mg/kg/day (divided q8h) of Augmentin for 10 days in the treatment of acute otitis media. Only the suspension formulations were used in this trial. 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, 87.2% (n = 265) and 82.3% (n = 260) for 45 mg/kg/day q12h and 40 mg/kg/day q8h, respectively. At follow-up, 67.1% (n = 249) and 68.7% (n = 243) for 45 mg/kg/day q12h and 40 mg/kg/day q8h, respectively.

Data from 2 pivotal studies 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 q12h to 500-mg tablets of Augmentin dosed q8h (584 and 607 patients, respectively). Comparable efficacy was demonstrated between the q12h and q8h dosing regimens. In one of these studies, 629 patients with either pyelonephritis or a complicated urinary tract infection were randomized to receive either 875-mg tablets of Augmentin q12h or 500-mg tablets of Augmentinq8h. The number of bacteriologically evaluable patients was comparable between the 2 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 1 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).