Serum and tissue tinidazole concentrations after intravenous infusion.

Before appendectomy 36 adult patients were given an intravenous infusion of 500 mg of tinidazole. In the operation tissue samples were taken (blood, base of appendix vermiformis, muscle, fat) either 10, 20, 30, 60, or 120 min after cessation of infusion. The tinidazole concentrations were determined by liquid chromatography. The weight-standardized tinidazole concentrations in the serum, muscle tissue and appendix in all specimens were higher than the minimal inhibitory concentration (2 micrograms/g) of Bacteroides fragilis. The tinidazole concentrations of adipose tissue exceeded the limit of 1 microgram/g in all samples. The concentrations were high already in the 10-min patient group. The authors consider a tinidazole infusion started half an hour before the operation at a dose of 10 mg/kg of the patient's body weight to be a reliable procedure if the objective is to acquire a sufficient tissue concentration of tinidazole (2 micrograms/g) to prevent infection complications caused by anaerobic bacteria.