Is the penetration of clindamycin into the masseter muscle really enough to treat odontogenic infections?

Objectives: This study aims to determine the penetration of clindamycin into the masseter muscle of rats by microdialysis and correlate with the main Microorganisms involved in odontogenic infections.

Materials and methods: Tissue concentrations of clindamycin in healthy muscle tissue were measured by microdialysis after administration of a single intravenous dose of 51 mg/kg and multiple doses of 17 mg/kg (8/8 h). It was quantified in plasma after a single administration of 51 mg/kg. Microdialysis samples were collected at 30-min intervals and clindamycin was assayed by LC-MS. Pharmacokinetic parameters and tissue penetration were determined. Pharmacokinetic/pharmacodynamic index (ƒ%T > minimum inhibitory concentration (MIC)) was considered to assess dosing regimens.

Results: The pharmacokinetic parameters determined by non-compartmental plasma analysis for the dose of 51 mg/kg were similar to that determined by compartmental analysis. The maximum free interstitial concentration (C_max) of clindamycin in muscle tissue was 14.20 (10.63-14.89) and 4.82 (3.35-6.66) mg/L for 51 mg/kg and 17 mg/kg 8/8 h, respectively. In addition, the area under the curve (AUC_0-inf) for plasma and tissue of clindamycin were 44.78 (28.82-65.65) and 16.54 (13.83-18.35) h.mg/L for 51 mg/kg, respectively, and the tissue penetration factor determined was 1.10. Considering that the main bacteria that cause odontogenic infections generally present MIC ≤ 0.5 mg/L, the ƒ%T > MIC index is reached when the dose regimen of 17 mg/kg 8/8 h is employed.

Conclusions: This investigation showed that clindamycin excellently penetrates muscle tissue of rats. It provides effective Antibacterial concentrations at the target site when 17 mg/kg 8/8 h is employed and can be applied to treat the main bacteria causing odontogenic infections.

Clinical relevance: It reinforces the use of clindamycin in odontogenic infections with significant tissue penetration.

Clindamycin; Microdialysis; Odontogenic infections; Pharmacokinetics; Tissue penetration.