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Biomedical subjects

B Drewelow

Publications and source records attributed to B Drewelow.

At least 19 recordsLinked to original sources
PubMed2006

Pharmacokinetic profiling of cyclosporine microemulsion during the first 3 weeks after simultaneous pancreas-kidney transplantation.

The optimal effect of therapy with cyclosporine (CsA) seeks to minimize undesirable side effects while maximizing immunosuppression. This balance, depends on CsA exposure, which may be characterized by the area under the concentration-time-curve (AUC). Therefore, we tested the pharmacokinetic profile of microemulsion CsA as a superior approach to guide clinical immunosuppression after de novo simultaneous pancreas-kidney transplantations. We examined 10 consecutive pancreas-kidney recipients with type 1 diabetes and end-stage renal disease. All patients were treated with a regimen consisting of CsA, mycophenolate mofetil (MMF), and prednisone. Full (9-point) pharmacokinetic studies (C0, C1, C2, C3, C4, C6, C8, C10, C12) were performed on week 1 and during week 3 to examine CsA pharmacokinetic profiles. Mean AUC0-12 of 4431 +/- 2400 microg x h/L at week 1 remained stable at week 3 (5119 +/- 1190 microg x h/L). The C6 sampling time displayed the best correlation with AUC0-12 (r2 = 0.881), followed by C3 (r2 = 0.758). Our preliminary data after simultaneous pancreas-kidney transplantation support the hypothesis that C3 or C6 sampling is a more accurate predictor of the AUC0-12 than C0. The combination of two samplings, namely C3 + C6 (r2 = 0.938) or C2 + C6 (r2 = 0.955) proved excellent prediction of exposure after simultaneous pancreas-kidney transplantation.

Area Under Curve↗
PubMed2005

Bioavailability and pharmacokinetics of caffeoylquinic acids and flavonoids after oral administration of Artichoke leaf extracts in humans.

Extracts from artichoke leaves are traditionally used in the treatment of dyspeptic and hepatic disorders. Various potential pharmacodynamic effects have been observed in vitro for mono- and dicaffeoylquinic acids (e.g. chlorogenic acid, cynarin), caffeic acid and flavonoids (e.g. luteolin-7-O-glucoside) which are the main phenolic constituents of artichoke leaf extract (ALE). However, in vivo not only the genuine extract constituents but also their metabolites may contribute to efficacy. Therefore, the evaluation of systemic availability of potential bioactive plant constituents is a major prerequisite for the interpretation of in vitro pharmacological testing. In order to get more detailed information about absorption, metabolism and disposition of ALE, two different extracts were administered to 14 healthy volunteers in a crossover study. Each subject received doses of both extracts. Extract A administered dose: caffeoylquinic acids equivalent to 107.0 mg caffeic acid and luteolin glycosides equivalent to 14.4 mg luteolin. Extract B administered dose: caffeoylquinic acids equivalent to 153.8 mg caffeic acid and luteolin glycosides equivalent to 35.2 mg luteolin. Urine and plasma analysis were performed by a validated HPLC method using 12-channel coulometric array detection. In human plasma or urine none of the genuine target extract constituents could be detected. However, caffeic acid (CA), its methylated derivates ferulic acid (FA) and isoferulic acid (IFA) and the hydrogenation products dihydrocaffeic acid (DHCA) and dihydroferulic acid (DHFA) were identified as metabolites derived from caffeoylquinic acids. Except of DHFA all of these compounds were present as sulfates or glucuronides. Peak plasma concentrations of total CA, FA and IFA were reached within 1 h and declined over 24 h showing almost biphasic profiles. In contrast maximum concentrations for total DHCA and DHFA were observed only after 6-7 h, indicating two different metabolic pathways for caffeoylquinic acids. Luteolin administered as glucoside was recovered from plasma and urine only as sulfate or glucuronide but neither in form of genuine glucosides nor as free luteolin. Peak plasma concentrations were reached rapidly within 0.5 h. The elimination showed a biphasic profile.

Administration, Oral↗
PubMed2003

[Drug interactions. Mechanisms and clinical relevance].

During the last few years 3 important drugs (terfenadine, mibefradil, cisapride) had to been withdrawn from the market because of serious drug-drug interactions. Polypragmacy, not only in advanced age, is often applied. Consequently the possibility of pharmacokinetic and/or pharmacodynamic drug interactions has always to be taken into account which can cause adverse effects, therapeutic failures, hospital admissions and extra costs. Clinically relevant interactions can be observed especially on the level of drug metabolism and transport. Both pharmacokinetic processes can be induced or inhibited by numerous agents. Taking proton pump inhibitors as an example it could be shown that the various compounds can differ in their interaction potential.

Drug Interactions↗
PubMed2001

The penetration of ciprofloxacin into human pancreatic and peripancreatic necroses in acute necrotizing pancreatitis.

BACKGROUND: Antibiotic prophylaxis in necrotizing pancreatitis has recently gained acceptance. Published studies, however, used different antibiotic regimes and some antibiotics penetrated pancreatic tissue or pancreatic necroses only poorly. The aim of this study was to assess the penetration of ciprofloxacin (CIP) into necrotic pancreatic and peripancreatic tissue. PATIENTS AND METHODS: Serum, pancreatic necroses, peripancreatic fat tissue necroses and infected omental fluid levels of CIP were measured after 51 operations in 14 patients. RESULTS: The median penetration ratio of CIP was 137.5% (range 11-196%) in infected omental bursa fluid, 59.6% (3-214%) in pancreatic necroses and 67.1% (1-250%) in peripancreatic necroses. Chemotherapeutical ratios of CIP as a marker for antimicrobial potency were high against most relevant pathogens in necrotizing pancreatitis. CONCLUSION: Due to its antimicrobial spectrum and the good penetration into the relevant compartments, CIP may be useful in preventing local infection in necrotizing pancreatitis.

Adult↗
PubMed2001

Pharmacokinetics and bioavailability of quercetin glycosides in humans.

Due to its potentially beneficial impact on human health, the polyphenol quercetin has come into the focus of medicinal interest. However, data on the bioavailability of quercetin after oral intake are scarce and contradictory. Previous investigations indicate that the disposition of quercetin may depend on the sugar moiety of the glycoside or the plant matrix. To determine the influence of the sugar moiety or matrix on the absorption of quercetin, two isolated quercetin glycosides and two plant extracts were administered to 12 healthy volunteers in a four-way crossover study. Each subject received an onion supplement or quercetin-4'-O-glucoside (both equivalent to 100 mg quercetin), as well as quercetin-3-O-rutinoside and buckwheat tea (both equivalent to 200 mg quercetin). Samples were analyzed by HPLC with a 12-channel coulometric array detector. In human plasma, only quercetin glucuronides, but no free quercetin, could be detected. There was no significant difference in the bioavailability and pharmacokinetic parameters between the onion supplement and quercetin-4'-O-glucoside. Peak plasma concentrations were 2.3 +/- 1.5 microg x mL(-1) and 2.1 +/- 1.6 microg x mL(-1) (mean +/- SD) and were reached after 0.7 +/- 0.2 hours and 0.7 +/- 0.3 hours, respectively. After administration of buckwheat tea and rutin, however, peak plasma levels were--despite the higher dose-only 0.6 +/- 0.7 microg x mL(-1) and 0.3 +/- 0.3 microg x mL(-1), respectively. Peak concentrations were reached 4.3 +/- 1.8 hours after administration of buckwheat tea and 7.0 +/- 2.9 hours after ingestion of rutin. The terminal elimination half-life was about 11 hours for all treatments. Thus, the disposition of quercetin in humans primarily depends on the sugar moiety. To a minor extent, the plant matrix influences both the rate and extent of absorption in the case of buckwheat tea administration compared with the isolated compound. The site of absorption seems to be different for quercetin-4'-O-glucoside and quercetin-3-O-rutinoside. The significance of specific carriers on the absorption of quercetin glycosides, as well as specific intestinal beta-glucosidases, needs to be further evaluated.

Adult↗
PubMed2000

Expression and function of beta-glucuronidase in pancreatic cancer: potential role in drug targeting.

Improvement of non-surgical strategies is a pivotal task in the treatment of pancreatic cancer. Response to treatment with most anticancer agents has been very poor, probably due to insufficient drug concentration in tumor tissue. Increased response rates during chemotherapy might be achieved by dose escalation; however, this approach is often hampered by severe side effects. One strategy to overcome these adverse effects is application of nontoxic glucuronide prodrugs from which the active moiety is released by beta-glucuronidase within or near the tumor. The use of glucuronide prodrugs in pancreatic cancer requires increased expression of the enzyme in the diseased tissue, a problem that has not been addressed so far. We therefore investigated function and expression of beta-glucuronidase in tissue samples from human healthy pancreas (n=7) and pancreatic adenocarcinoma (n=8), respectively. Comparing the ability of tissue homogenates to cleave the standard substrate 4-methylumbelliferyl-beta-D-glucuronide, we found a significantly increased specific beta-glucuronidase activity (P<0.05) in pancreatic cancer (median: 133; 75% percentile: 286; 25% percentile: 111 nmol/mg per h) as compared to healthy pancreas (median: 74; 75% percentile: 113; 25% percentile: 71 nmol/mg per h). Enzyme kinetic experiments with the model prodrug N-[4-beta-glucuronyl-3-nitrobenzyloxycarbonyl] doxorubicin (HMR 1826) demonstrated bioactivation of HMR 1826 by pancreatic beta-glucuronidase. Enzymatic activity was found to be closely related to enzyme contents (r=0.87) as assessed by Western blot analysis. Our data indicate that increased beta-glucuronidase activity in pancreatic cancer seems to be due to an elevated steady-state level of the protein. This may be the basis for new therapeutic strategies in treatment of pancreatic carcinoma by using glucuronide prodrugs of anticancer agents.

Adenocarcinoma↗
PubMed2000

Comparison of several approaches of therapeutic drug monitoring of cyclosporin A based on individual pharmacokinetics.

OBJECTIVE: The clinical outcome of patients after organ transplantation is correlated with cyclosporin A (CyA) exposure. It is generally accepted that the area under the concentration-time curve (AUC) provides a reliable means for drug exposure. However, in routine therapeutic drug monitoring (TDM) of CyA, trough levels are mostly used. Currently, a number of different new concepts of CyA-TDM, including approaches such as single, double or triple time-point and abbreviated AUC determinations, have been introduced. The purpose of this study was to compare the predictive value of the different strategies of TDM. METHODS: Calculations were based on 40 individual concentration time profiles after oral administration of CyA to patients who had been included into an ongoing prospective clinical trial. Non-compartmental analysis was used to calculate the AUC0-12h. Multiple linear regression was performed to describe the relationship between the different sets of blood concentrations and the respective AUC0-12h as well as to evaluate their predictive value regarding AUC. Predictive performance was assessed by prediction bias and prediction precision, which were estimated as the mean prediction error and root mean squared error, respectively. RESULTS: When comparing the various combinations of time points, it was found that one-point approaches showed the strongest differences with regard to the predictive value; the associated r2 values differed from 0.203 to 0.792. The two and three time-point approaches showed lower differences - r2 0.802-0.972. The four-point and five-point approaches (r2 0.942-0.982) were the strongest predictors for CyA AUC0-12h. Relative bias ranged from -27.7% to 63.8% and changed significantly when multiple-point predictors were used. In those cases, the predictive performance improved. Considering the predictive performance as well as the smallest bias and highest prediction precision, C3, C1 + C3, C1 + C3 + C6 and C1 + C2 + C3 + C6 were the best predictors. CONCLUSION: The results of this study indicate that in kidney transplant patients a clinically sufficient precise estimation of the CyA AUC is possible using two or three concentration time points.

Adult↗
PubMed1999

Improved penetration of aminoglycosides and fluorozuinolones into the aqueous humour of patients by means of Acuvue contact lenses.

OBJECTIVES: In order to improve the penetration of topically applied drugs in ophthalmology, the suitability of hydrophilic contact lenses (Acuvue, Vistacon, power -1.0 D) as a drug delivery system for antibiotics was tested. A prospective study was undertaken to determine the transcorneal penetration of five topically applied aminoglycosides and fluoroquinolones into the aqueous humour of patients. METHODS: Two hundred and sixty-five patients undergoing cataract extraction received 0.3% gentamicin, kanamycin, tobramycin, ciprofloxacin or ofloxacin solution by two different modes of administration: either as eye drops (nine drops every 15 min, starting 2 h prior to surgery) or by means of a drug delivery system (Acuvue contact lenses soaked for 1 h in eye drop solution without preservatives, 15 h prior to surgery). At the beginning of cataract extraction, 50-100 microl aqueous fluid was aspirated from the anterior chamber and immediately stored at -80 degrees C. Antibiotic concentrations were measured using fluorescence polarisation immunoassays (aminoglycosides) or high-performance liquid chromatography (fluoroquinolones). RESULTS: After soaking for 1h in 0.3% eye drop solutions, Acuvue contact lenses released about 190-250 microg aminoglycoside and ofloxacin and 1000 microg ciprofloxacin. These amounts are considerably lower or in the same order of magnitude than obtained with application of eye drops (1350 microg). From the aminoglycosides tested, only gentamicin and tobramycin, but not kanamycin, were able to penetrate into the aqueous humour of patients. After the wearing of antibiotic-soaked lenses, mean aqueous humour concentrations were higher than after the use of eye drops. This difference reached significance in tobramycin (1.09 (1.30) microg x ml(-1) vs 0.49 (0.79) microg x ml(-1)), ciprofloxacin (1.23 (0.60) microg x ml(-1) vs 0.38 (0.33) microg x ml(-1)) and ofloxacin (5.55 (2.53) microg x ml(-1) vs 0.56 (0.37) microg x ml(-1)). The percentage of patients with aqueous humour concentration above the MIC90 of Staphylococcus epidermidis, the most common cause of postoperative endophthalmitis, was 92% and 100% after wearing ciprofloxacin- or ofloxacin-soaked lenses, respectively. CONCLUSION: Gentamicin and tobramycin penetrated into the aqueous humour of patients, whereas kanamycin was not able to overcome the corneal barrier. Acuvue contact lenses soaked in 0.3% eye drop solutions can release sufficient amounts of gentamicin, ciprofloxacin and ofloxacin to produce bacteriostatic concentrations in the humor aquosus. Acuvue contact lenses can be recommended as a drug delivery system for fluoroquinolones.

Administration, Topical↗
PubMed1999

Penetration of ciprofloxacin, norfloxacin and ofloxacin into the aqueous humor using different topical application modes.

BACKGROUND: A prospective study was undertaken to determine the transcorneal penetration of three topically applied fluoroquinolones into aqueous humor. METHODS: Cataract patients (n = 224) preoperatively received topically applied gyrase inhibitors (0.3% ciprofloxacin, 0.3% norfloxacin, 0.3% ofloxacin) in two different application modes. In application mode I, patients received on the day before operation 3 x 1 eye drop at 2-h intervals, and on the day of operation 3 drops at 1-h intervals. In application mode II, patients received 9 drops at 15-min intervals on the day of operation only. Just before cataract surgery 50-100 ml aqueous humor was aspirated and stored at -80 degrees C. The HPLC method was used for measuring the concentration. RESULTS: The highest concentrations of all tested antibiotics were measured after the mode of application in which one drop was given every 15 min between 06:00 and 08:00 hours before operation. In this mode, ciprofloxacin achieved a mean aqueous level of 379.8 +/- 327.8 mg/l (range 33-1388 mg/l), norfloxacin 182.1 +/- 118.1 mg/l (range 38-480 mg/l) and ofloxacin 563.9 +/- 372.1 mg/l (range 64-1455 mg/l). These mean concentration are all above the MIC90 of gram-negative bacteria like Proteus mirabilis and Escherichia coli. In some cases the concentrations of ciprofloxacin and ofloxacin, but never norfloxacin, reached therapeutic values above the MIC90 of Staphylococcus aureus and Staphylococcus epidermidis. CONCLUSIONS: The mean concentration value of 0.3% ciprofloxacin and of 0.3% ofloxacin in the aqueous humor reached the MIC90 values of the frequently occurring gram-positive and gram-negative bacteria. Of the currently available topical fluoroquinolones, ofloxacin achieved the highest aqueous humor concentration. Considering the higher antimicrobial activity of ciprofloxacin, both ciprofloxacin and ofloxacin may be useful ophthalmic agents in antibacterial management, but they are not efficient against Streptococcus pneumoniae and Pseudomonas aeruginosa.

Administration, Topical↗
PubMed1999

Perioperative antibiotic prophylaxis in maxillofacial surgery: penetration of clindamycin into various tissues.

Although clindamycin is recommended for prophylactic use in oral and maxillofacial surgery, there is little data available regarding its ability to provide sufficient tissue concentrations at the operative site. We investigated tissue samples from 31 patients, who had to undergo oral and maxillofacial surgery and who received at least one dose of 600 mg clindamycin i.v. preoperatively, to determine clindamycin tissue concentrations in muscle, oral mucosa, fatty tissue, skin and bone between 15 min and 8 h after administration. After homogenization, clindamycin concentration was determined by bioassay. It was demonstrated that clindamycin concentrations above the MIC90 of those pathogens most likely to cause contamination were reached in all kinds of tissues investigated. Already 15 min after administration, tissue concentrations above the MIC90 were reached and were still detectable in the last samples taken between 4 and 8 h after the last clindamycin administration. From the pharmacokinetic point of view, clindamycin is suitable for perioperative prophylaxis during oral and maxillofacial surgery providing sufficient tissue concentrations with no intraoperative additional dosage necessary unless procedures exceed 4 h duration.

Absorption↗
PubMed1998

[Corneal penetration of various aminoglycosides and quinolones].

BACKGROUND: Penetration of the aminoglycosides gentamicin and tobramycin and chinolones ciprofloxacin and ofloxacin applied as eyedrops and soaked disposable lenses (ACUVUE), used as antibiotic prophylaxis, was investigated. MATERIALS AND METHODS: 217 patients received before undergoing cataract extraction 0.3% solutions of these antibiotics as eyedrops or by soaked ACUVUE-lenses. During surgery 50-100 microliters aqueous humor was aspirated; concentration of gentamicin and tobramycin was analysed by fluorescence polarisation immuno assay, concentration of ciprofloxacin and ofloxacin was analysed by high pressure liquid chromatography. RESULTS: After application of gentamicin and ofloxacin as eyedrops and via soaked ACUVUE-lenses as drug delivery system (DDS) we found higher concentrations than after application of tobramycin and ciprofloxacin by the same modes. After using of soaked lenses as DDS the aqueous humor concentrations of all tested substances were higher than the concentrations after the frequent instillation of eyedrops. CONCLUSIONS: Penetration of gentamicin through normal human cornea is higher than penetration of tobramycin; penetration of ofloxacin through normal human cornea is higher than penetration of ciprofloxacin. The aqueous humor concentrations of ofloxacin applied as eyedrops and DDS, of ciprofloxacin and gentamicin applied as DDS allow their use as antibiotic prophylaxis in cataract surgery.

Anti-Bacterial Agents↗
PubMed1998

Up-regulation of cytochrome P450 1A2, 2C9, and 2E1 in chronic pancreatitis.

The oxidative metabolism of xenobiotics is effected mainly by cytochrome P450 enzymes (CYP), which are expressed as a family of genetically related enzymes primarily in hepatocytes. The pancreas is among the extrahepatic tissues expressing CYP, and it has been suggested that intermediates generated by them might be of pathogenetic significance for diseases of the pancreas such as chronic pancreatitis. We studied 10 surgical resection specimens by immunohistochemistry with polyclonal antibodies against recombinant human CYP 1A1, 1A2, 2C9, 2E1, and 3A and used tissues from 11 normal pancreata as controls. In addition, we assayed microsomal preparations for their capacity to metabolize verapamil. In normal pancreata weak to moderate expression of all enzymes was demonstrated immunohistochemically in up to 50% of duct epithelia, acinar cells, and islet cells. In contrast, in chronic pancreatitis an up-regulation was observed, with immunohistochemical positivity in some cases in up to 100% of duct epithelia and acinar cells. The oxidative capacity of microsomal preparations from chronic pancreatitis was higher than that of preparations obtained from control tissues; compared to liver microsomes, however, it was low. The up-regulation of CYP may have pathogenetic significance for chronic pancreatitis. Yet considering the pancreas' capacity for conjugation reactions, conceivably low levels of reactive intermediates could effectively undergo inactivation.

Adult↗
PubMed1997

Prediction of in vivo drug interaction from in vitro systems exemplified by interaction between verapamil and cimetidine using human liver microsomes and primary hepatocytes.

Emphasis on drug safety is increasing as newly developed drugs become more potent. Interest in the prediction and description of drug interactions is growing accordingly. The study of potential interactions at a very early stage of drug development requires suitable in vitro models that describe drug interactions both qualitatively and quantitatively. The purpose of the work described here was to help assess the predictive value of in vitro drug interaction tests with liver microsomes and hepatocytes by means of the interaction between verapamil and cimetidine. The in vitro inhibition of verapamil metabolism by cimetidine observed during the studies was quantitatively similar to the results reported in published clinical studies after intravenous application. Studies using liver microsome fractions showed that the intrinsic clearances for the formation of various metabolites could be used to predict drug interactions. In addition, work with hepatocyte cultures revealed that an in vitro system covering both phase I and phase II reactions should be included in such studies to permit quantitative prediction of the various metabolic pathways. Both human hepatocyte cultures and human microsomes offer certain advantages for predicting the degree of drug metabolism and interactions in humans at the biotransformation level. Therefore, it seems likely that the simultaneous application of both systems will yield conclusions that most closely approximate the situation in humans.

Animals↗
PubMed1997

Pharmacokinetics of mezlocillin and sulbactam under continuous veno-venous hemodialysis (CVVHD) in intensive care patients with acute renal failure.

OBJECTIVE: In intensive care medicine, continuous detoxication methods, such as continuous veno-venous hemodialysis (CVVHD), are used for treating acute renal failure. However, in contrast to conventional hemodialysis, little is known about the pharmacokinetics of many drugs administered in this setting and guidelines for dosages of drugs often do not exist. This holds particularly true for broad-spectrum antibiotics, which are often required during intensive care. METHODS: In this study, we investigated the pharmacokinetics of the acylureidopenicillin mezlocillin and the beta-lactamase inhibitor sulbactam during CVVHD and deduced dosage recommendations from the kinetic parameters with the goal of maintaining trough levels of above 10 mg.l-1 for mezlocillin and 5 mg.l-1 for sulbactam. Six intensive care patients with acute renal failure, receiving mezlocillin (n = 5) and/or sulbactam (n = 4), were examined during CVVHD and during intervals between CVVHD. The serum concentrations and the amounts of the drugs excreted into the dialyzate and into the urine within one dosage interval were measured using high performance liquid chromatography (HPLC). Three of the patients were jaundiced, indicating functional impairment of the liver. RESULTS: The clearances by CVVHD (CLCVVHD) for mezlocillin ranged between 11.0 and 44.9 ml.min-1 and the half lives ranged between 1.12 and 8.84 h. Low CL and long half lives were observed in the patients with jaundice. For sulbactam, CLCVVHD ranged between 10.1 and 22.8 ml.min-1 and serum half lives were 4.25-6.11 h, independent of liver function. CONCLUSION: Due to high hepatobiliary clearance of mezlocillin, dosage adjustments in patients with acute renal failure, treated by CVVHD, are needed only with concurrent impaired liver function. For sulbactam, the optimal dose was found to be 0.5 g, administered every 12 h, regardless of liver function.

Acute Kidney Injury↗
PubMed1997

Penetration of ciprofloxacin, norfloxacin and ofloxacin into the aqueous humours of patients by different topical application modes.

OBJECTIVE: A prospective study was undertaken to determine the transcorneal penetration of three topically applied fluoroquinolones into aqueous humour. METHODS: Two hundred and twenty-four patients undergoing cataract extraction received 0.3% ciprofloxacin, norfloxacin or ofloxacin eye drops by two different administration modes with different frequencies and intervals of application. At the beginning of cataract extraction (0.5-3 h after the last drop), 50-100 microliters aqueous fluid was aspirated from the anterior chamber and immediately stored at -80 degrees C. Antibiotic concentrations were measured using high-performance liquid chromatography. RESULTS: Generally, topical ofloxacin and ciprofloxacin yielded aqueous humour levels higher than topical norfloxacin. The highest concentrations of all tested fluoroquinolones were measured after using an application mode, in which one drop was given every 15 min between 0600 hours and 0800 hours, prior to operation. When applied by this mode, ciprofloxacin achieved a mean aqueous level of 0.380 (+/- 0.328) microgram.ml-1 (range 0.033-1.388 micrograms.ml-1), norfloxacin 0.182 (0.118) microgram.ml-1 (range 0.038-0.480 microgram.ml-1) and ofloxacin 0.564 (0.372) microgram.ml-1 (range 0.064-1.455 micrograms.ml-1). These mean concentrations were above the minimum inhibitory concentration (MIC90), concentrations required for inhibition of 90% of pathogen strains in vitro of gram-negative bacteria, such as Proteus mirabilis and Escherichia coli. Therapeutic values above the MIC90 of Staphylococcus epidermidis, the pathogen causing eye infections most frequently, were reached by 67.5% of patients after ofloxacin and by 41% after ciprofloxacin, but never after norfloxacin treatment. CONCLUSION: Of the currently available topical fluoroquinolones, ofloxacin achieved the highest aqueous humour concentration. This fluoroquinolone may be an useful ophthalmic agent for topical antibacterial management, but it does not seem to be prophylactically effective against Streptococcus pneumoniae or Pseudomanas aeruginosa.

Administration, Topical↗