Concentration of phenoximethylpenicillin, clindamycin and tinidazole in dental cysts

In the treatment of bacterial infections, adequate antibiotic concentrations must be realised at the site of infection. Levels of 3 antibiotics--phenoximethylpenicillin, clindamycin and tinidazole - were measured in serum and fluid of periapical odontogenic cysts in 30 patients undergoing enucleation of periapical cysts. After a single dose of 500 mg tinidazole, the concentration of tinidazole in the cystic fluid was 4.3 micrograms/ml, which was about 1/3 of the concentration in the serum. No measurable levels were achieved in the cystic fluid with phenoximethylpenicillin or clindamycin.