Intraoperative concentrations of ofloxacin in serum, bile fluid, and gallbladder wall tissue

Population Pharmacokinetics of Levofloxacin in Plasma and Bone of Patients Undergoing Hip or Knee Surgery

Patients undergoing hip or knee replacement therapy are routinely pretreated with antibiotics before they enter the operation theater. This treatment intends to reduce the incidence of peri- or postsurgical infections. Here, we calculated the uptake kinetics of levofloxacin into bone to see whether levofloxacin could be obtained from the trabecular and cortical bone and at what time concentrations are sufficiently high to inhibit the usual hospital infections. Patients (n = 42) undergoing routine surgery were treated with 500 mg levofloxacin intravenously immediately prior to the operation. Plasma samples were taken before and at 3 points after termination of drug infusion. After replacement of the bones, extracts were obtained from them. Levofloxacin was quantified using high-performance liquid chromatography. The kinetics of levofloxacin and its distribution into bone were analyzed using a population approach (ADAPT5). Clearance was 14.0 L/h, and distribution volume was 77 L. Bone uptake t½ was calculated as 4.2 and 5.4 hours for cortical bone and trabecular bone, respectively. In knee samples (but not in hip samples), we noted that the cortical bone contained higher levels of levofloxacin than the trabecular bone. From our data, we can conclude that levofloxacin might be useful for prophylactic use in bone surgery.

An HPLC assay and a microbiological assay to determine levofloxacin in soft tissue, bone, bile and serum

A simple, specific and sensitive HPLC assay for levofloxacin in serum, bile, soft tissue and bone was evaluated and validated. The samples were prepared by protein precipitation with acids and methanol, which yielded high recoveries (for serum and bile>98% and for bone and soft tissue>90%). The compounds were separated on a reversed phase column with an acidic mobile phase containing triethylamine. The eluate was monitored by fluorescence detection. The HPLC assay is linear over the usable concentration range (0.1-40 microg/ml) and it provides good validation data for accuracy and precision. Although comparison of HPLC results to the results of a microbiological assay showed congruent results (regression coefficients>0.967). HPLC should be the method of choice for determination of levofloxacin in biological matrices.

Ofloxacin clinical pharmacokinetics

Ofloxacin is a new fluoroquinolone with a spectrum of activity similar to other fluoroquinolones with activity which includes Chlamydia trachomatis, Mycobacterium spp., Mycoplasma spp. and Legionella pneumophila. Through its additional mechanisms of action, ofloxacin may be less susceptible to the development of resistance from Staphylococcus aureus commonly seen with currently available fluoroquinolones. The impact of these findings cannot be evaluated without further clinical experience. The pharmacokinetics of ofloxacin are characterised by almost complete bioavailability (95 to 100%), peak serum concentrations in the range of 2 to 3 mg/L after a 400mg oral dose and an average half-life of 5 to 8h. In comparison with other available quinolones, elimination is more highly dependent on renal clearance, which may lead to more frequent dosage adjustments in patients with impaired renal function. Ofloxacin appears less likely to affect the pharmacokinetics of drugs (e.g. theophylline) which commonly interact with fluoroquinolones such as ciprofloxacin and enoxacin. The properties of ofloxacin make it a therapeutic alternative to currently available fluoroquinolones.

Ofloxacin. A reappraisal of its antimicrobial activity, pharmacology and therapeutic use

Ofloxacin is a fluoroquinolone whose primary mechanism of action is inhibition of bacterial DNA gyrase. In vitro it has a broad spectrum of activity against aerobic Gram-negative and Gram-positive bacteria, although it is poorly active against anaerobes. Ofloxacin, unlike most other broad spectrum antibacterial drugs, can be administered orally as well as intravenously. Penetration into body tissues and fluids is highly efficient. Clinical trials with orally and intravenously administered ofloxacin have confirmed its potential for use in a wide range of infections, where it has generally proved as effective as standard treatments. Ofloxacin in well tolerated, and in comparison with other available fluoroquinolones is less likely to cause clinically relevant drug interactions. Ofloxacin thus offers a valuable oral treatment (with an option for intravenous administration if necessary) for use in a wide range of clinical infections, but with a particular advantage in more severe or chronic infections when recourse to parenteral broad spectrum agents would normally be required, thereby providing cost savings and additionally allowing outpatient treatment.