Plasma penicillin-G parameters in man after intraduodenal or intramuscular administration.

Concentrations of penicillin-G produced in serum by either direct intraduodenal (i.d.) or intramuscular (i.m.) administration were compared in 9 healthy volunteers. Serum specimens were assayed by the Sarcina lutea cup plate method. The peak serum levels achieved by i.d. application were similar to those observed after intramuscular dose. However, higher concentrations were better sustained after i.m. penicillin. We concluded that intraduodenal administration of penicillin-G could be considered as an alternative for i.m. injection.