[Penicillin VK absorption during fasting and after eating].

The absorption of penicillin VK (Rafapen) was evaluated in 12 children, 3-16 years.old, with infections due to penicillin-sensitive organisms. In each, 50 mg/kg of Rafapen was given after an overnight fast, and the next day the same amount was administered after a standard hospital breakfast. Blood samples were drawn before and 30, 60 and 90 min after the drug was given. Serum penicillin levels were determined by comparing the inhibition of growth on plates of Staphylococcus aureus (Oxford strain), with that of standard penicillin G concentrations. The serum levels after the overnight fast were higher, 4.75 U/ml, as compared to 3.38 U/ml 30 min after the drug was given following breakfast. This increase was abolished at 60 and 90 min, when the serum levels were 1.96 and 1.05 U/ml, respectively. We advise the use of oral penicillin VK in infections due to penicillin-sensitive organisms, without regard to feeding schedule.