Pharmacologic and clinical comparison of cefaclor in immediate-release capsule and extended-release tablet forms

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.

Antibiotic treatment for acute 'uncomplicated' or 'primary' pyelonephritis: a systematic, 'semantic revision'

The definition of acute pyelonephritis is controversial. There are two contrasting approaches: (1) acute pyelonephritis is a severe infectious disease involving the kidney parenchyma, and specific imaging techniques are required for diagnosis; (2) acute pyelonephritis is a urinary tract infection, and diagnosis and therapy follow simplified clinical and laboratory pathways. In this study, recent randomized controlled trials (RCTs) were systematically reviewed and the diagnostic and therapeutic approaches to acute 'uncomplicated' pyelonephritis were analysed. Medline, Embase, Cochrane Central Register of Controlled Trials (CCTR) and Chinal were searched employing Mesh, Emtree and free terms on 'pyelonephritis'. Limits included human, period (1995-2004), and trials-reviews (where available). In total, 904 references and 175 full-text were retrieved; 29 were pertinent RCTs. Seven RCTs were added from reference lists (indexed on urinary tract infections). Imaging examinations were performed in 11 of 14 studies on children (diagnostic requisite in two) and in two studies on adults; scarring was not analysed in adults. Clinical definitions varied widely (fever >37.8 to >39 degrees C, culture titres 10(4) >10(5)). Studies on adults were limited to short-term end-points (microbiological sterilization, clinical improvement). Duration of therapy was 4-20 days. The trend was towards shorter periods of therapy, mainly on an outpatient basis; intravenous therapy, if performed, was usually limited to the first 1-3 days. For acute uncomplicated pyelonephritis, the tendency is towards 2 weeks of mainly oral antibiotic therapy. However, the recent literature on adults does not discriminate among different upper urinary tract infections nor does it provide data on renal scarring. While cost constraints point towards short-term therapies, further studies are needed to assess the prevalence and long-term effect of kidney scars.

Determination of cefaclor in human plasma by a sensitive and specific liquid chromatographic-tandem mass spectrometric method

A sensitive and specific liquid chromatographic-tandem mass spectrometric method is described for the determination of cefaclor in human plasma. The plasma samples were treated by two sample preparation procedures, i.e. protein precipitation (PPT) and solid-phase extraction (SPE). The pretreated samples were analyzed on a C(18) HPLC column interfaced with a triple quadrupole tandem mass spectrometer. Positive electrospray ionization (ESI) was employed as the ionization source. The analyte and internal standard ampicillin (for PPT) or cefetamet (for SPE) were detected by use of selected reaction monitoring (SRM) mode. The lower limit of quantitation obtained as a result of the PPT procedure was 100 ng/ml. The intra- and inter-run precision, calculated from quality control (QC) samples was less than 12% for cefaclor. The accuracy as determined from QC samples was within +/-3% for the analyte. The SPE procedure could provide the lower limit of quantitation of 2 ng/ml. The precision and accuracy were measured to be below 7.1% and between -3.6% and 1.1%, respectively, for all QC samples. The method was applied for the evaluation of the pharmacokinetic profiles of cefaclor sustained-release formulation.

Cefaclor revisited

OBJECTIVE

This paper describes the rationale for choosing cefaclor for the management of respiratory tract infections.

BACKGROUND

Since 1979, cefaclor has established a record of efficacy in the management of respiratory tract infections. Factors contributing to the efficacy and tolerability of this drug include its molecular stability, activity against the most prevalent gram-positive and gram-negative respiratory tract pathogens, rapid absorption, >90% bioavailability, and good penetration into respiratory mucosa. After 2 decades of widespread use, this agent remains clinically effective in patients with respiratory tract infections, making it competitive with other cephalosporins and with macrolides and fluoroquinolones, including many newer agents used for respiratory tract infections. Cefaclor extended-release tablets, the newest formulation, retain the positive efficacy and tolerability attributes of immediate-release cefaclor, varying mainly in the rate of dissolution. The approved indications for extended-release cefaclor include bacterial bronchitis, pharyngitis, and skin infections.

METHODS

A MEDLINE search showed that the few adverse effects related to therapy with cefaclor are usually minor and transient and that drug-drug interactions involving cefaclor are rare.

CONCLUSIONS

Multiple clinical trials have shown that extended-release cefaclor in 375-mg and 500-mg doses BID demonstrates tolerability and efficacy comparable to those of immediate-release cefaclor 250 mg TID. Extended-release cefaclor is indicated for BID dosing, which should encourage greater compliance.