Loracarbef. A review of its antimicrobial activity, pharmacokinetic properties and therapeutic efficacy

The use of drug metabolism for prediction of intestinal permeability (dagger)

The Biopharmaceutics Classification System (BCS), based on the aqueous solubility and intestinal permeability of a drug substance, has been widely used to predict the extent of drug absorption during the course of pharmaceutical development. Combined with product dissolution data, this system has gained a prominent role in regulatory process to determine if a drug formulated in an immediate release solid oral dosage form qualifies for waiver of in vivo bioequivalence studies. In parallel, the Biopharmaceutics Drug Disposition Classification System (BDDCS), using aqueous solubility and drug metabolism, takes on another venue to predict overall drug disposition. It has been suggested that the matrix of drug metabolism in BDDCS can be used to substantiate the classification of permeability by BCS. A total of 51 drugs were compiled in this study to examine the use of drug metabolism for predicting permeability. All compounds were classified as high permeability based on BCS, but only 73% of the compounds were found to exhibit extensive metabolism. Lipophilicity accounts for significant metabolism of many highly permeable drugs. Fourteen (14) out of 51 drugs have poor metabolism, suggesting that high permeability as defined by BCS does not necessarily dictate extensive metabolism. The drugs that have high permeability but poor metabolism are generally hydrophilic molecules with low molecular weight and are likely to be absorbed by active transport mechanisms. Based on the present data and literature information, it seems logical to predict that the extent of absorption is mostly complete (or > or =90%) if the drug is subject to a high degree of metabolism (e.g., > or =90%). The extent of drug metabolism may be useful in supporting permeability classification under certain circumstances.

The effect of four different types of diet on the bioavailability of loracarbef

This randomized open-label single-dose crossover pharmacokinetic study was carried out to assess the effect of different diets on the bioavailability of loracarbef in 24 healthy male volunteers. A single dose of loracarbef in 200-mg tablet form was administered at 5 different times: after overnight fasting, after two vegetarian (high-fat and low-fat) diets, and following two non-vegetarian (high-fat and low-fat) diets. Serial blood samples were collected up to 10 h post-dose. Serum loracarbef concentrations were determined by a validated high performance liquid chromatographic (HPLC) method. Area under curve (AUC) values were significantly affected only by non-vegetarian diets; however the time to reach maximum serum concentration (Tmax) was prolonged and the maximum serum concentration (Cmax was decreased by all types of meals. The non-vegetarian diets affected the rate of absorption of loracarbef more than the vegetarian diets. The lowest decrease in Cmax was produced by the high-fat vegetarian diet, while the maximum was produced by the low-fat non-vegetarian diet. The results of this study indicate that while the rate of loracarbef absorption is significantly decreased by all diets, the extent of absorption is only reduced significantly by the non-vegetarian diets. The rate of elimination (k(el)) was not found to be significantly decreased by any of the diets. As compared to the high-fat non-vegetarian diet, the time beyond minimum inhibitory concentration (MIC90) concentration was significantly increased by the high-fat vegetarian diet. The implications of these findings for the large Indian vegetarian population are considerable.

Adverse events associated with the use of oral cephalosporins/cephems

Historically, oral cephalosporins represent one of the most widely used and safest classes of antimicrobials available. Typical adverse events have included nausea, vomiting, diarrhea, and hypersensitivity reactions. Other more serious events such as pseudomembranous colitis, although infrequent, may occur. The exact type and incidence of adverse events varies depending on the cephalosporin being administered. Differences in adverse event profiles may also vary by age of the patient. Reactions are usually not severe and often do not require termination of therapy. The purpose of this review is to present to healthcare providers the historical safety profile of the most commonly used oral cephalosporins.

Staphylococcal skin infections in children: rational drug therapy recommendations

Staphylococcus aureus remains one of the most common and troublesome of bacteria causing disease in humans, despite the development of effective antibacterials and improvement in hygiene. The organism is responsible for over 70% of all skin and soft tissue infections in children and accounts for up to one-fifth of all visits to pediatric clinics. Skin and soft tissue infections that are predominantly caused by S. aureus include bullous and non-bullous impetigo, folliculitis, furunculosis, carbunculosis, cellulitis, surgical and traumatic wound infections, mastitis, and neonatal omphalitis. Other skin and soft tissue infections may also be caused by S. aureus but are often polymicrobial in origin and require special consideration. These include burns, decubitus ulcers (particularly in the perianal region), puncture wounds of the foot, as well as human and mammalian bites. Treatment of staphylococcal skin infections varies from topical antiseptics to prolonged intravenous antibacterials, depending on severity of the lesions and the health of the child. The treatment of choice for oral antibacterials remains the penicillinase-resistant penicillins such as flucloxacillin. Cefalexin and erythromycin are suitable cost-effective alternatives with broader cover, although care must be taken with the use of macrolides because of development of resistance to multiple families of antibacterials, particularly the lincosamides. Other cephalosporins such as cefadroxil and cefprozil are also effective, can be given once daily and have a better tolerability profile -- while azithromycin has a further advantage of a 3-day course. However, all of these agents are more expensive. Although the antibacterials have been given for 10 days in most clinical trials, there is no evidence that this duration is more effective than a 7-day course. In children requiring intravenous therapy, ceftriaxone has a major advantage over other antibacterials such as sulbactam/ampicillin and cefuroxime in that it can be given once daily and may, therefore, be suitable for outpatient treatment of moderate-to-severe skin infections. Newer-generation cephalosporins and loracarbef are also effective and have a broader spectrum of activity, but do not offer any added benefit and are significantly more expensive. Skin and soft tissue infections due to methicillin-resistant S. aureus (MRSA) are still relatively uncommon in children. Well children with community-acquired MRSA infections can be treated with clindamycin or trimethoprim-sulfamethoxazole (cotrimoxazole), but must be observed closely for potentially severe adverse effects. In severe infections, vancomycin remains the treatment of choice, while intravenous teicoplanin and clindamycin are suitable alternatives. Linezolid and quinupristin/dalfopristin are currently showing great promise for the treatment of multi-resistant Gram-positive infections. While the choice of antibacterial is important, supportive management, including removal of any infected foreign bodies, surgical drainage of walled-off lesions, and regular wound cleaning, play a vital role in ensuring cure.

Multiple pharmacokinetic parameter prediction for a series of cephalosporins

The goal of quantitative structure-pharmacokinetic relationship analyses is to develop useful models that can predict one or more pharmacokinetic properties of a particular compound. In the present study, a multiple-output artificial neural network model was constructed to predict human half-life, renal and total body clearance, fraction excreted in urine, volume of distribution, and fraction bound to plasma proteins for a series of cephalosporins. Descriptors generated solely from drug structure were used as inputs for the model, and the six pharmacokinetic parameters were simultaneously predicted as outputs. The final 10 descriptor model contained sufficient information for successful predictions using both internal and external test compounds. Descriptors were found to contribute to individual pharmacokinetic parameters to differing extents, such that descriptor importance was independent of the relationships between pharmacokinetic parameters. This technique provides the advantage of simultaneous prediction of multiple parameters using information obtained by nonexperimental means, with the potential for use during the early stages of drug development.

Antibiotics in the management of pediatric skin disease

An increasingly large number of antibiotics are available for the treatment of uncomplicated skin and skin structure infections in children. Primary factors in the choice among these agents are the antibiotic resistance profile of the target pathogen(s), and the antibiotic's spectrum of activity, pharmacologic properties, potential adverse reactions and interactions and propensity to select for the emergence of resistant organisms. Based on a consideration of these principles, this article provides a practical guide to the use of antibiotics in the management of common cutaneous infections in the pediatric population.

Efficacy of sinus irrigation versus sinus irrigation followed by functional endoscopic sinus surgery

Sinus irrigation is the traditional treatment for chronic maxillary sinusitis. Functional endoscopic sinus surgery (FESS) restores aeration and allows secretions to be removed from an infected sinus. This study compares the efficacy of sinus irrigation with that of sinus irrigation followed by FESS in 89 patients. We measured the effects by way of sinus radiographs, nasendoscopic findings, and patient complaints. When we analyzed the data in terms of intent to treat, we found significantly favorable results for sinus irrigation followed by FESS at the end point, though only for loss of smell and purulent rhinitis. Treatment consisting of sinus irrigation alone prevented surgery in 58% of all patients for 1 year. Both treatment methods were combined with a 10-day course of loracarbef, which might have contributed to the outcome. We conclude that a good option for treatment of chronic maxillary sinusitis seems to be sinus irrigation in combination with a broad-spectrum antibiotic followed by FESS.