Comparative effect of food on absorption of ampicillin and pivampicillin

The effect of food on the absorption of simultaneously ingested ampicillin or pivampicillin was compared in a crossover study in eight healthy volunteers. The absorption of both ampicillin and pivampicillin was delayed by simultaneous food intake as judged by serum concentration and urinary excretion of ampicillin. The total absorption of ampicillin, but not that of pivampicillin was decreased by simultaneous food intake as indicated by the are under the serum ampicillin concentration-time curves and by 24 hours urinary excretion of ampicillin. The excretion of ampicillin into urine was about 30% of the dose when ampicillin was ingested with water into an empty stomach and about 20% when ingested with food. The respective excretion of ampicillin following the ingestion of pivampicillin was about 60% of the dose taken either with or without food.