Concomitant use of probenecid is not recommended. Probenecid decreases the renal tubular secretion of amoxicillin. Concomitant use with Co-Amoxiclav may result in increased and prolonged blood levels of amoxicillin but not of clavulanate.
Concomitant use of allopurinol during treatment with amoxicillin can increase the likelihood of allergic skin reactions. There are no data on the concomitant use of Co-Amoxiclav and allopurinol.
In common with other antibiotics, Co-Amoxiclav may affect the gut flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral contraceptives.