Since the 1970s, amoxicillin has been the most extensively used penicillin, both alone and in combination with the -lactamase inhibitor clavulanic acid.
We re-examine the characteristics of oral amoxicillin and clavulanic acid in this narrative review and offer recommendations for their administration, with an emphasis on the use of amoxicillin alone.
Medical literature that has been published (MEDLINE database via Pubmed).
While the half-lives of amoxicillin and clavulanic acid are comparable, clavulanic acid is more protein-bound and even less heat stable than amoxicillin, and its metabolism is largely hepatic. It is also more strongly linked to gastrointestinal adverse effects, such as Clostridium difficile infection, and hence limits the maximum daily dose of amoxicillin that can be administered in oral combination formulations. Due to clavulanic acid’s high affinity for -lactamases, the first ratio for an amoxicillin-clavulanic acid combination was set at 4:1; now, ratios of 2:1, 7:1, 14:1, and 16:1 are available in various countries. There is a scarcity of comparative effectiveness data for the various ratios.
Many of the World Health Organization’s Priority Infectious Syndromes in adults and children are treated with amoxicillin-clavulanic acid as empiric therapy, resulting in extensive consumption when some of these syndromes could be treated with a delayed antibiotic prescription approach or amoxicillin alone.
We present recommendations for amoxicillin versus amoxicillin-clavulanic acid indications and optimal oral delivery, including the choice of combination ratio, based on available epidemiological and pharmacokinetic data. More information is needed, especially on heat stability, pharmacodynamic effects, and resistance emergence in real-world’ clinical situations.