Jane S. Ricciuti, RPh, MS


October 23, 2002

In This Article

Anti-infective Agents

Augmentin XR (Amoxicillin/Clavulanate Potassium) Extended-release Tablets, 1000 mg/62.5 mg

Manufacturer: GlaxoSmithKline

Drug Approval Classification: Original New Drug Application (Approval Date: 9/25/02)

Indication: Augmentin XR extended-release tablets are indicated for the treatment of patients with community-acquired pneumonia (CAP) or acute bacterial sinusitis due to confirmed or suspected beta-lactamase-producing pathogens (ie, H influenzae, M catarrhalis, H parainfluenzae, K pneumoniae, or methicillin-susceptible S aureus) and S pneumoniae with reduced susceptibility to penicillin.

Dosing: Augmentin XR should be taken at the start of a meal to enhance the absorption of amoxicillin and to minimize the potential for gastrointestinal intolerance. The recommended dose of Augmentin XR is 4000 mg/250 mg daily according to the following Table 1 .

  • Acute bacterial sinusitis: 2 tablets every 12 hours for 10 days.

  • Community-acquired pneumonia: 2 tablets every 12 hours for 7-10 days.

Augmentin tablets (250 mg or 500 mg) CANNOT be used to provide the same dosages as Augmentin XR extended-release tablets.

Clinical Summary: Augmentin XR is contraindicated in patients with a history of allergic reactions to any penicillin. It is also contraindicated in patients with a previous history of cholestatic jaundice/hepatic dysfunction associated with treatment with amoxicillin/clavulanate.

Augmentin XR is contraindicated in patients with severe renal impairment (creatinine clearance < 30 mL/min) and in hemodialysis patients.

For the indication of CAP, 3 randomized, controlled, double-blind clinical studies in adults with CAP were conducted. Patients received Augmentin XR at a dosage of 2000/125 mg orally every 12 hours for 7 or 10 days. The clinical success rate at test of cure ranged from 86.3% to 94.7% in clinically evaluable patients in the Augmentin XR group.

Three clinical studies were conducted in adults with a diagnosis of acute bacterial sinusitis. In a double-blind, multicenter prospective trial, patients received either Augmentin XR 2000/125 mg orally q12h or levofloxacin 500 mg orally daily for 10 days. The combined clinical and radiologic responses were 83.7% for Augmentin XR and 84.3% for levofloxacin at the test-of-cure visit in clinically evaluable patients.

Adverse Effects: The safety database contains more than 4100 patients treated with Augmentin XR in clinical trials. The most common adverse effects suspected or probably drug-related were diarrhea (15.6%), nausea (2.2%), genital moniliasis (2.1%), and abdominal pain (1.6%).

Pharmacokinetics: Augmentin XR is an extended-release formulation that provides sustained plasma concentrations of amoxicillin. Absorption of amoxicillin is decreased in the fasted state. Augmentin XR is not recommended to be taken with a high-fat meal, because clavulanate absorption is decreased.

The half-life of amoxicillin after oral administration of Augmentin XR is approximately 1.3 hours, and that of clavulanate is approximately 1.0 hour.

Clearance of amoxicillin is predominantly renal, with approximately 60% to 80% of the dose being excreted unchanged in urine, whereas clearance of clavulanate has both a renal (30% to 50%) and a nonrenal component.

Drug interactions include:

  • Probenecid -- decreases the renal tubular secretion of amoxicillin.

  • Concomitant allopurinol and ampicillin administration increases substantially the incidence of rashes in patients receiving both drugs as compared with patients receiving ampicillin alone.

  • Oral contraceptive efficacy may be reduced, as seen with other broad-spectrum antibiotics.

Augmentin XR (Amoxicillin/Clavulanate Potassium) extended-release tablets Labeling



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