xicillin diffuses readily into most body tissues and fluids, with the exception of brain and spinal fluid, except when meninges are inflamed. Amoxicillin is approximately 20% protein bound in human serum.
Amoxicillin is primarily cleared by renal excretion. Approximately 60% of an oral dose of immediate-release amoxicillin is eliminated unchanged in urine. The half-life of amoxicillin after oral administration of MOXATAG is approximately 1.5 hours, similar to that of immediate-release amoxicillin. No accumulation of amoxicillin was observed after once-daily dosing of 775 mg of MOXATAG for 7 days.
Drug Interactions
In a study of healthy adult subjects, amoxicillin AUC was similar whereas Cmax increased approximately 35% following the administration of lansoprazole with MOXATAG given with food.
Probenecid decreases the renal tubular secretion of amoxicillin. Concurrent use of MOXATAG and probenecid may result in increased and prolonged blood levels of amoxicillin. The clinical relevance of this finding has not been eva luated.
12.4 Microbiology
Amoxicillin is a semi-synthetic antimicrobial belonging to the penicillin class of antimicrobials with activity against gram-positive bacteria.
Mechanism of Action
Amoxicillin exerts its bactericidal action against susceptible organisms during the stage of multiplication. It acts through the inhibition of biosynthesis of cell wall mucopeptide.
Mechanism of Resistance
To date there are no known mechanisms of resistance to penicillin or amoxicillin in Streptococcus pyogenes.
MOXATAG has been shown to be active in vitro against isolates of the microorganism S. pyogenes and in clinical infections as described in the INDICATIONS AND USAGE section.
Facultative Gram-Positive Bacteria:
Streptococcus pyogenes
The following in vitro data are available, but their clinical significance is unknown. At least 90% of the following microorganisms exhibit an in vitro minimum inhibitory concentration (MIC) less than or equal to the susceptibility breakpoint of amoxicillin (as determined by susceptibility tests using the class representative agents penicillin or ampicillin).
Facultative Gram-Positive Bacteria:
Streptococcus spp. (Group B, C, and G; β-hemolytic)
Susceptibility Test Methods:
When available, the clinical microbiology laboratory should provide cumulative results of the in vitro susceptibility test results for antimicrobial drugs used in local hospitals and practice areas to the physician as periodic reports that describe the susceptibility profile of nosocomial and community-acquired pathogens. These reports should aid the physician in selecting the most effective antimicrobial.
Susceptibility testing of penicillins (such as amoxicillin) and other β-lactams approved by FDA for the treatment of Group A streptococcus (S. pyogenes) is not routinely necessary for clinical purposes. Isolates of Group A streptococcus resistant to amoxicillin have not been recognized and therefore all isolates can be considered susceptible to amoxicillin However, susceptibility tests can be conducted using dilution or diffusion techniques employing penicillin or ampicillin to predict susceptibility to amoxicillin.
Dilution Techniques
Quantitative methods are used to determine antimicrobial MICs. These MICs provide estimates of the susceptibility of bacteria to antimicrobial compounds. The MICs should be determined using a stan |
