From the Guidelines
Augmenting amoxicillin coverage with clavulanic acid is recommended for treating infections likely caused by beta-lactamase producing organisms, particularly in cases of complicated respiratory infections, sinusitis, otitis media with treatment failure, skin/soft tissue infections, and bite wounds. The combination of amoxicillin and clavulanic acid, known as amoxicillin-clavulanate or Augmentin, provides broader coverage than amoxicillin alone, especially against organisms like H. influenzae, M. catarrhalis, S. aureus, and certain Enterobacteriaceae 1. Standard adult dosing for amoxicillin-clavulanate is 875/125 mg twice daily or 500/125 mg three times daily for 7-10 days, depending on the infection type. For children, dosing is typically 45 mg/kg/day divided twice daily based on the amoxicillin component 1. The addition of clavulanic acid works by inhibiting bacterial beta-lactamase enzymes that would otherwise break down the beta-lactam ring of amoxicillin, rendering it ineffective. However, this broader coverage comes with increased gastrointestinal side effects, particularly diarrhea, so it should be used only when clinically indicated rather than as a first-line option for all infections.
Some key points to consider when deciding whether to augment amoxicillin coverage include:
- The severity of the infection and the likelihood of beta-lactamase producing organisms being present
- The patient's medical history, including recent antibiotic use and attendance at child care
- The local prevalence of nonsusceptible S. pneumoniae and beta-lactamase positive H. influenzae
- The potential for increased gastrointestinal side effects with amoxicillin-clavulanate
According to the most recent guidelines, amoxicillin-clavulanate is recommended as initial empirical therapy for acute bacterial sinusitis in children, particularly in cases where there is a high prevalence of beta-lactamase producing H. influenzae 1. In adults, amoxicillin-clavulanate is also recommended as an option for initial therapy, especially in cases of complicated respiratory infections or sinusitis 1.
It's worth noting that the optimal duration of antimicrobial therapy for patients with acute bacterial sinusitis has not received systematic study, but recommendations based on clinical observations have varied widely, from 10 to 28 days of treatment 1.
In summary, augmenting amoxicillin coverage with clavulanic acid is a recommended approach for treating certain types of infections, particularly those caused by beta-lactamase producing organisms. However, the decision to use amoxicillin-clavulanate should be based on a careful consideration of the patient's individual circumstances and the local epidemiology of resistant organisms.
From the FDA Drug Label
Bacteriological eradication on therapy (day 4-6 visit) in the per protocol population is summarized in Table 5. Table 5. Bacteriologic Eradication Rates in the Per Protocol Population Pathogen Bacteriologic Eradication on Therapy n/N % 95% CI* All S. pneumoniae 121/123 98.4 (94.3,99.8) S. pneumoniae with penicillin MIC = 2 mcg/mL 19/19 100 (82. 4,100) S. pneumoniae with penicillin MIC = 4 mcg/mL 12/14 85.7 (57.2,98.2) H. influenzae 75/81 92.6 (84.6,97.2) M. catarrhalis 11/11 100 (71. 5,100)
The FDA drug label does not directly compare Augmentin (amoxicillin/clavulanate) to amoxicillin in terms of coverage. However, it provides information on the bacteriologic eradication rates of amoxicillin/clavulanate against various pathogens, including:
- S. pneumoniae: 98.4% eradication rate
- H. influenzae: 92.6% eradication rate
- M. catarrhalis: 100% eradication rate It is essential to note that the label does not provide a direct comparison to amoxicillin, and therefore, no conclusion can be drawn regarding the relative coverage of Augmentin vs amoxicillin 2.
From the Research
Amoxicillin vs Augmentin Coverage
- Amoxicillin/clavulanate (Augmentin) is a broad-spectrum antibacterial that provides coverage of beta-lactamase-producing pathogens and has a favourable pharmacokinetic/pharmacodynamic (PK/PD) profile 3.
- The combination of amoxicillin and clavulanate has been shown to be effective in treating community-acquired respiratory tract infections, including those caused by drug-resistant pathogens such as Streptococcus pneumoniae 3.
- Augmentin has been compared to other antibiotics, such as levofloxacin, in the treatment of community-acquired pneumonia, and has been found to be effective and safe 4.
- Amoxicillin/clavulanate has also been evaluated for the treatment of urinary tract infections caused by ceftriaxone non-susceptible Enterobacterales, and has been found to be a useful alternative therapy 5.
- The properties, indications, and usage of oral amoxicillin and amoxicillin-clavulanic acid have been reviewed, and it has been suggested that amoxicillin alone may be preferred in some cases, while amoxicillin-clavulanic acid may be more appropriate for empiric therapy in certain situations 6.
Key Differences
- Amoxicillin and Augmentin have different coverage spectra, with Augmentin providing broader coverage of beta-lactamase-producing pathogens 3.
- The choice between amoxicillin and Augmentin may depend on the specific infection being treated, as well as the presence of drug-resistant pathogens 3, 5.
- Amoxicillin-clavulanic acid is often used as empiric therapy for many infectious syndromes, but may not always be necessary, and amoxicillin alone may be sufficient in some cases 6.
Clinical Efficacy
- Augmentin has been shown to be clinically effective in treating community-acquired respiratory tract infections, including those caused by drug-resistant pathogens 3, 4.
- Amoxicillin/clavulanate has also been found to be effective in treating urinary tract infections caused by ceftriaxone non-susceptible Enterobacterales 5.
- The clinical efficacy of moxifloxacin versus comparator therapies, including amoxicillin/clavulanate, has been evaluated for the treatment of community-acquired pneumonia caused by Legionella spp. 7.