Lessons from isavuconazole therapeutic drug monitoring at a United Kingdom Reference Center.

We determined isavuconazole serum concentrations for 150 UK patients receiving standard isavuconazole dosing regimens, including serial therapeutic drug monitoring for several patients on prolonged therapy. Mean trough isavuconazole concentrations in these patients were virtually identical to those reported previously from clinical trials, although greater variability was seen in patients below 18 years of age. Serial monitoring in patients receiving prolonged therapy suggested gradual, near-linear accumulation of the drug over many weeks.

Impact of soaking gentamicin-containing collagen implants on potential antimicrobial efficacy.

Background: The purpose of this study is to evaluate how wetting of Collatamp (a gentamicin-containing collagen implant [GCCI]) impacts on the gentamicin content of the implant and whether this affects its potential antibacterial efficacy.

Methods: GCCI (Collatamp(®), EUSA Pharma [Europe], Oxford, United Kingdom) containing 130 mg gentamicin and 280 mg collagen (10 cm × 10 cm) were immersed in 300 mL normal saline for up to 6h. At set times after immersion the GCCI were removed, the saline diluted in normal human serum and the gentamicin content assayed by a validated immunoassay (Cedia, Microgenics Ltd, UK) to provide an estimate of the loss from each implant.

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).

Emergence of fluoroquinolone resistance in the native Campylobacter coli population of pigs exposed to enrofloxacin.

Objective: The effect of a single 5 day enrofloxacin treatment on the native Campylobacter coli population in conventionally weaned 5-week-old pigs was investigated.

Materials: Twelve pigs were split into two groups of six: one group was treated with a therapeutic dose (15 mg/pig/day) of enrofloxacin and the other remained untreated to act as the control. Campylobacter coli were isolated from faecal samples and tested for ciprofloxacin resistance by measuring MIC values.

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.