Transfer of penicillin G and ampicillin into human skin blisters induced by suction.

The antibiotic concentrations in untreated and endotoxin-treated suction blisters was studied in 15 healthy adults. In a pilot study, 2 mega units of penicillin G were given as an intravenous bolus injection to two subjects. For further studies, a single dose of 800 mg bacampicillin was given orally to 13 individuals. The penicillin G concentrations in the blister fluid were highest approximately 15 minutes after the dose, and exceeded that of serum after 1.5 hours. With ampicillin the blister fluid concentration reached maximum levels after approximately 2 hours, were equal to serum levels after 3 hours, and were later persistently in excess of serum levels. The ampicillin half-life was 136 and 100 minutes in the two types of blister fluid, as compared to 65 minutes for serum. A marked differences between the antibiotic concentrations in inflammatory and non-inflammatory blisters was seen in the pilot study with penicillin G. However, in the experiments with bacampicillin, no significant difference was demonstrated. This suction blister technique appears to be a useful method for studies on extravascular antimicrobial activity in man.