Amoxicillininteractions

Coadministration with probenecid is not recommended. Concomitant use of amoxicillin and clavulanate potassium for oral suspension, 600 mg/42.9 mg per 5 mL with oral anticoagulants may increase the prolongation of prothrombin time. Coadministration with allopurinol increases the risk of rash. Amoxicillin and clavulanate potassium for oral suspension, 600 mg/42.9 mg per 5 mL may reduce efficacy of oral contraceptives.

7.1 Probenecid

Probenecid decreases the renal tubular secretion of amoxicillin. Concurrent use with amoxicillin and clavulanate potassium for oral suspension, 600 mg/42.9 mg per 5 mL may result in increased and prolonged blood levels of amoxicillin. Coadministration of probenecid is not recommended.

7.2 Oral Anticoagulants

Abnormal prolongation of prothrombin time (increased international normalized ratio [INR]) has been reported in patients receiving amoxicillin and oral anticoagulants. ​​​​​​​Appropriate monitoring should be undertaken when anticoagulants are prescribed concurrently. Adjustments in the dose of oral anticoagulants may be necessary to maintain the desired level of anticoagulation.

7.3 Allopurinol

The concurrent administration of allopurinol and amoxicillin increases substantially the incidence of rashes in patients receiving both drugs as compared to patients receiving amoxicillin alone. It is not known whether this potentiation of amoxicillin rashes is due to allopurinol or the hyperuricemia present in these patients. There are no data with amoxicillin and clavulanate potassium for oral suspension, 600 mg/42.9 mg per 5 mL and allopurinol administered concurrently.

7.4 Oral Contraceptives

Amoxicillin and clavulanate potassium for oral suspension, 600 mg/42.9 mg per 5 mL may affect intestinal flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral estrogen/progesterone contraceptives.

7.5 Effects on

Laboratory Tests High urine concentrations of amoxicillin may result in false-positive reactions when testing for the presence of glucose in urine using CLINITEST ®, Benedict’s Solution, or Fehling’s Solution. Since this effect may also occur with amoxicillin and clavulanate potassium for oral suspension, 600 mg/42.9 mg per 5 mL, it is recommended that glucose tests based on enzymatic glucose oxidase reactions be used. Following administration of amoxicillin to pregnant women, a transient decrease in plasma concentration of total conjugated estriol, estriol-glucuronide, conjugated estrone, and estradiol has been noted.