From the Guidelines
The oral bioavailability of amoxicillin-clavulanate is approximately 70-90% for amoxicillin and 60-75% for clavulanic acid. This medication is well absorbed from the gastrointestinal tract, with food generally enhancing the absorption of clavulanic acid while slightly decreasing the rate (but not extent) of amoxicillin absorption. For optimal absorption, amoxicillin-clavulanate should be taken at the start of a meal or with food, which helps minimize potential gastrointestinal side effects while maintaining therapeutic efficacy.
Key Points
- The high bioavailability of amoxicillin-clavulanate contributes to its effectiveness as an oral antibiotic option, allowing it to achieve therapeutic concentrations at infection sites without requiring intravenous administration in most cases 1.
- The extended-release formulation (Augmentin XR) has modified absorption characteristics designed to provide sustained blood levels.
- After absorption, both components distribute well throughout body tissues and fluids, including the respiratory tract, middle ear, and sinus cavities, making the combination effective for treating various bacterial infections.
Clinical Considerations
- The oral bioavailability of amoxicillin-clavulanate supports its use in treating bacterial infections, including those caused by Streptococcus pneumoniae and Haemophilus influenzae 1.
- The medication's effectiveness is further enhanced by its ability to distribute well throughout the body, allowing it to reach therapeutic concentrations at infection sites.
- The high bioavailability of amoxicillin-clavulanate makes it a suitable option for oral antibiotic therapy, reducing the need for intravenous administration and associated complications.
From the Research
Oral Bioavailability of Amoxicillin-Clavulanate
- The oral bioavailability of amoxicillin-clavulanate is not directly stated in the provided studies 2, 3, 4, 5, 6.
- However, study 4 mentions that the absorption of amoxicillin is nonlinear and may be affected by the presence of clavulanic acid, which could potentially decrease the absolute bioavailability of clavulanic acid.
- Study 6 compares the bioavailability of different amoxicillin formulations, but does not provide information on the bioavailability of amoxicillin-clavulanate specifically.
- Study 5 discusses the bioequivalence of clavulanic acid in amoxicillin-clavulanic acid oral formulations, but does not provide a specific value for the oral bioavailability of amoxicillin-clavulanate.
- Study 3 provides pharmacokinetic parameters for clavulanic acid after oral administration of amoxicillin and potassium clavulanate, but does not provide information on the oral bioavailability of amoxicillin-clavulanate.
Pharmacokinetic Parameters
- Study 3 reports the following pharmacokinetic parameters for clavulanic acid:
- t 1/2 beta = 1.019 +/- 0.090 hour
- t 1/2 alpha = 0.276 +/- 0.031 hour
- lag time = 0.321 +/- 0.018 hour
- tmax = 1.042 +/- 0.80 hour
- Cmax = 2.098 +/- 0.441 micrograms/ml
- AUC = 4.897 +/- 0.979 micrograms X hr/ml
- These parameters provide information on the absorption and elimination of clavulanic acid, but do not directly address the oral bioavailability of amoxicillin-clavulanate 3.