Penetration of clindamycin and metronidazole into inflamed appendiceal tissue.

OBJECTIVE

To calculate the penetration of clindamycin and metronidazole into inflamed appendiceal tissue.

DESIGN

Prospective study.

SETTING

Teaching hospital, Israel.

SUBJECTS

20 Consecutive men and women operated on for acute appendicitis.

INTERVENTIONS

Appendicectomy. Each patient was given three intravenous injections of gentamicin 80 mg combined with either clindamycin 600 mg or metronidazole 500 mg immediately before operation over a period of 15 minutes.

MAIN OUTCOME MEASURES

Serum and tissue concentrations of the antibiotics.

RESULTS

There was no significant difference between the mean serum concentrations of the drugs (clindamycin 17.86 micrograms/ml and metronidazole 9.75 micrograms/ml) but the mean tissue concentrations of clindamycin (10.41 micrograms/g in the base and 9.86 micrograms/g in the tip of the appendix) were significantly higher than those of metronidazole (5.65 micrograms/g in the base and 5.89 micrograms/g in the tip; p = 0.02 and p = 0.05, respectively). Tissue concentrations of clindamycin and serum concentration of both drugs were more than twice their MIC90. The tissue concentrations of metronidazole were close to its MIC90.

CONCLUSIONS

Clinical trials are necessary before any conclusion about therapeutic superiority of one or other agent can be drawn.