Evidence of excessive concentrations of 5-flucytosine in children aged below 12 years: a 12-year review of serum concentrations from a UK clinical assay reference laboratory.

5-flucytosine (5-FC) is an antifungal drug used for the treatment of serious infections caused by Candida or Cryptococcus spp. In the UK, the recommended pre- and post-dose serum therapeutic ranges are 30-40 mg/L and 70-80 mg/L, respectively. A 12-year retrospective review of serum concentrations of 5-FC in three groups of children aged 1-30 days (n=167), 31-60 days (n=102) and 91 days to 12 years (n=122) was conducted.

Determination of avilamycin A and B in pig faeces by solid phase extraction and reverse-phase HPLC assay.

A HPLC method is described for the simultaneous determination of avilamycin A and B in pig faeces, following extraction using acetonitrile and normal-phase solid phase extraction. The HPLC stationary phase was Kromosil 5 micro C-18 with a mobile phase of 48% acetonitrile and 52% 0.01N ammonium acetate buffer, pumped at a flow rate of 1 ml/min.

A reverse-phase HPLC assay for the simultaneous determination of enrofloxacin and ciprofloxacin in pig faeces.

A reverse-phase HPLC assay is described for the simultaneous assay of enrofloxacin (ENR) and ciprofloxacin (CPX) in pig faeces. Extraction used dichloromethane, 2-propanol and 0.3M ortho-phosphoric acid (1:5:4 v/v/v).

Serum and sputum concentrations following the oral administration of linezolid in adult patients with cystic fibrosis.

Objectives: Linezolid is a new oxazolidinone antibiotic with efficacy against a broad range of Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). In this study, we have determined the serum and sputum linezolid concentrations in adults with cystic fibrosis (CF) following oral drug administration.

Methods: Eleven adult patients with CF were recruited.

Evaluation of commercial assays for vancomycin and aminoglycosides in serum: a comparison of accuracy and precision based on external quality assessment.

Objective: To compare the accuracy and precision of commercial assay techniques in the measurement of gentamicin, tobramycin, amikacin, netilmicin and vancomycin in serum.

Methods: Data from the measurement of 40 external quality assessment samples from 358 laboratories providing a therapeutic drug monitoring service were analysed.

Results: Significant differences between techniques in accuracy and precision were observed for all drugs.

Determination by HPLC of chlortetracycline in pig faeces.

An HPLC assay used to determine chlortetracycline (CTC) in pig faeces is reported. Prodigy ODS3 (4.6 x 150 mm) was used for the stationary phase, whereas the mobile phase comprised oxalic acid, sodium oxalate and sodium decane sulfonate (66%)--each of 4 mM, and 34% acetonitrile.