Cefurex 250: Concomitant administration of probenecid with Cefuroxime increases the area under the serum concentration versus time curve by 50%. The peak serum cefuroxime concentration after a 1.5-g single dose is greater when taken with 1 g of probenecid (mean = 14.8 mcg/mL) than without probenecid (mean = 12.2 mcg/mL). Drugs that reduce gastric acidity may result in a lower bioavailability of Cefuroxime compared with that of fasting state and tend to cancel the effect of postprandial absorption. In common with other antibiotics, Cefuroxime may affect the gut flora, leading to lower estrogen reabsorption and reduced efficacy of combined oral estrogen/progesterone contraceptives.