Petra Czarniak

Clinical setting influences off-label and unlicensed prescribing in a paediatric teaching hospital

Purpose To estimate the prevalence of off-label and unlicensed prescribing during 2008 at a major paediatric teaching hospital in Western Australia. Methods A 12-month retrospective study was conducted at Princess Margaret Hospital using medication chart records randomly selected from 145,550 patient encounters from the Emergency Department, Inpatient Wards and Outpatient Clinics. Patient and prescribing data were collected. Drugs were classified as off-label or unlicensed based on Australian registration data. A hierarchical system of age, indication, route of administration and dosage was used. Drugs were classified according to the Anatomical Therapeutic Chemical Code. Results A total of 1,037 paediatric patients were selected where 2,654 prescriptions for 330 different drugs were prescribed to 699 patients (67.4%). Most off-label drugs (n = 295; 43.3%) were from the nervous system; a majority of unlicensed drugs were systemic hormonal preparations excluding sex hormones (n = 22, 32.4%). Inpatients were prescribed more off-label drugs than outpatients or Emergency Department patients (p < 0.0001). Most off-label prescribing occurred in infants and children (31.7% and 35.9% respectively) and the highest percentage of unlicensed prescribing (7.2%) occurred in infants (p < 0.0001). There were 25.7% of off-label and 2.6% of unlicensed medications prescribed across all three settings. Common reasons for off-label prescribing were dosage (47.4%) and age (43.2%). Conclusion This study confirmed off-label and unlicensed use of drugs remains common. Further, that prevalence of both is influenced by the clinical setting, which has implications in regards to medication misadventure, and the need to have systems in place to minimise medication errors. Further, there remains a need for changes in the regulatory system in Australia to ensure that manufacturers incorporate, as it becomes available, evidence regarding efficacy and safety of their drugs in children in the official product information.

The influence of non-HLA gene polymorphisms and interactions on disease risk in a Western Australian multiple sclerosis cohort

Non-Human Leukocyte Antigen (HLA) genes have concomitant, although modest, effects on multiple sclerosis (MS) susceptibility; however findings have varied in different populations. Here we present the results of an association study of 16 single nucleotide polymorphisms (SNPs) in 10 non-HLA genes (IL7R, IL2RA, CLEC-16A, TYK2, CD58, IRF5, STAT3, CTLA-4, APOE, ICAM-1) in a Western Australian cohort of 350 MS patients and 498 population control subjects. Our results indicate that in this population, SNPs in IL7R, TYK2, IRF5 and APOE have modifying effects on MS susceptibility. We also found evidence of interactive protective effects between polymorphisms in the IL7R/CD58, CLEC-16A/CTLA-4, and TYK2/IRF5 genes, which in some instances are restricted within HLA- or gender-defined groups.

Stability studies of lincomycin hydrochloride in aqueous solution and intravenous infusion fluids

Purpose The purpose of this study was to evaluate the chemical stability of Lincocin® (lincomycin hydrochloride) in commonly used intravenous fluids at room temperature (25°C), at accelerated-degradation temperatures and in selected buffer solutions. Materials and methods The stability of Lincocin® injection (containing lincomycin 600 mg/2 mL as the hydrochloride) stored at 25°C±0.1°C in sodium lactate (Hartmann’s), 0.9% sodium chloride, 5% glucose, and 10% glucose solutions was investigated over 31 days. Forced degradation of Lincocin® in hydrochloric acid, sodium hydroxide, and hydrogen peroxide was performed at 60°C. The effect of pH on the degradation rate of lincomycin hydrochloride stored at 80°C was determined. Results Lincomycin hydrochloride w as found to maintain its shelf life at 25°C in sodium lactate (Hartmann’s) solution, 0.9% sodium chloride solution, 5% glucose solution, and 10% glucose solution, with less than 5% lincomycin degradation occurring in all intravenous solutions over a 31-day period. Lincomycin hydrochloride showed less rapid degradation at 60°C in acid than in basic solution, but degraded rapidly in hydrogen peroxide. At all pH values tested, lincomycin followed first-order kinetics. It had the greatest stability near pH 4 when stored at 80°C (calculated shelf life of 4.59 days), and was least stable at pH 2 (calculated shelf life of 0.38 days). Conclusion Lincocin® injection was chemically found to have a shelf life of at least 31 days at 25°C when added to sodium lactate (Hartmann’s) solution, 0.9% sodium chloride solution, 5% glucose solution, and 10% glucose solution. Solutions prepared at approximately pH 4 are likely to have optimum stability.

Incorporating online teaching in an introductory pharmaceutical practice course: a study of student perceptions within an Australian University

Objective To examine student perceptions regarding online lectures and quizzes undertaken during a pharmaceutical practice course for first year undergraduate students enrolled in the Bachelor of Pharmacy course at an Australian University. Methods The University uses a standard instrument to collect feedback from students regarding unit satisfaction. Data were collected for three different teaching modalities: traditional face-to-face, online and partially online. Results Descriptive statistics support that, from a students perspective, partial online delivery is the preferred teaching methodology for an introductory pharmaceutical practice unit. Conclusions This study has served to highlight that while there are a few points of significant difference between traditional and online teaching and learning, a combination of the two provides a reasonable avenue for teaching exploration. This result has implications for teaching practice generally, and within the pharmacy discipline, specifically.

New method for testing the absorbency of surgical dressings.

Abstract— Absorbent cellulose dressings have been tested by immersion in a standard aqueous solution of picric acid followed by standard draining, elution of the picric acid, and measurement of the absorbance of the yellow colour at 355 nm. Six samples of gauze were graded by this procedure, and two considered unsatisfactory, despite all sinking in less than 10s. Filmated gauzes and unwoven dressings required greater dilution for the absorbance readings, reflecting their different structures.

Surgical antibiotic prophylaxis use and infection prevalence in non-cosmetic breast surgery procedures at a tertiary hospital in Western Australia—a retrospective study

Background Surgical site infections (SSIs) are a common complication following breast surgery procedures, despite being considered a clean surgery. The prevalence of SSIs can be minimised with the appropriate use of antibiotic prophylaxis as outlined in the Australian Therapeutic Guidelines (eTG). The aims of this study were to evaluate adherence to the eTG for antibiotic prophylaxis in breast surgery procedures at a Western Australian teaching hospital following an update of the guidelines in 2014 and examine the impact of prophylactic antibiotics on SSI incidence and length of hospital stay. Method A retrospective cross-sectional study which reviewed medical records from a random sample of 250 patients selected from 973 patients who underwent breast surgical procedures between February 2015 and March 2017. Results Overall adherence to current eTG occurred in 49.2% (123/250) of operations. Pre-operative and post-operative antibiotics were prescribed in 98.4% (246/250) and 11.2% (28/250) operations respectively. Adherence rates to three specific elements of the eTG (drug prescribed, drug dosage and timing of administration) were 91.6% (229/250), 53.6% (134/250) and 86.4% (216/250) respectively. For the 14.4% (36/250) patients with relevant drug allergies, there was zero adherence to the eTG. Overall recorded SSI prevalence was low at 5.2% (13/250). The mean length of stay in patients (2.3 ± 1.7 days) was not influenced by level of eTG adherence (p = 0.131) or SSIs (p = 0.306). Conclusion These data demonstrate a significant improvement in overall adherence to the eTG from 13.3% to 49.2% (p = < 0.001). The level of detected SSIs in this study was low. Further improvement is necessary with respect to prescribing appropriate antibiotic dosages and for those with allergies.

A survey of the views and capabilities of community pharmacists in Western Australia regarding the rescheduling of selected oral antibiotics in a framework of pharmacist prescribing

Background Antibiotic misuse in the community contributes to antimicrobial resistance. One way to address this may be by better utilizing community pharmacists’ skills in antibiotic prescribing. The aims of this study were to examine the level of support for “down-scheduling” selected antibiotics and to evaluate factors determining the appropriateness of community pharmacist prescribing for a limited range of infections, including their decision to refer to a doctor. Methods Self-administered questionnaires, including graded case vignette scenarios simulating real practice, were sent to Western Australian community pharmacists. In addition to descriptive statistics and chi-square testing, a General Estimating Equation (GEE) was used to identify factors associated with appropriateness of therapy and the decision to refer, for each of the seven vignettes. Results Of the 240 pharmacists surveyed, 90 (37.5%) responded, yielding 630 responses to seven different case vignettes. There was more than 60% respondent support for expanded prescribing (rescheduling) of commonly prescribed antibiotics. Overall 426/630 (67.6%) chose to treat the patient while the remaining 204/630 (32.4%) referred the patient to a doctor. Of those electing to treat, 380/426 (89.2%) opted to use oral antibiotics, with 293/380 (77.2%) treating with an appropriate selection and regimen. The GEE model indicated that pharmacists were more likely to prescribe inappropriately for conditions such as otitis media (p = 0.0060) and urinary tract infection in pregnancy (p < 0.0001) compared to more complex conditions. Over 80% of all pharmacists would refer the patient to a doctor following no improvement within 3 days, or within 24 h in the case of community acquired pneumonia. It was more common for younger pharmacists to refer the patient to a doctor (p = 0.0165). Discussion This study adds further insight into community pharmacy/pharmacist characteristics associated with appropriateness of oral antibiotic selection and the decision to refer to doctors. These findings require consideration in designing pharmacist over-the-counter prescribing models for oral antibiotics.

Evaluation of the stability of linezolid in aqueous solution and commonly used intravenous fluids

Purpose The aim was to evaluate the stability of linezolid in commonly used intravenous fluids and in aqueous solution to determine the kinetics of degradation and shelf-life values at alkaline pH values. Methods Forced degradation studies were performed on linezolid in solution to develop a validated high-performance liquid chromatography analysis. Sodium chloride 0.9%, sodium lactate, and glucose 5% and glucose 10% solution containing 2.0 mg/mL linezolid were stored at 25.0°C (±0.1°C) for 34 days. The effect of temperature on the stability of linezolid in 0.1 M sodium hydroxide solution was investigated to determine the activation energy. The degradation rates of linezolid at selected pH values at 70.0°C and the influence of ionic strength were also examined. Activation energy data were applied to determine the shelf-life values at selected pH values, and a pH rate profile was constructed over the pH range of 8.7–11.4. The stability of intravenous linezolid (Zyvox®) solution was evaluated by storing at 70.0°C for 72 hours. Results Linezolid was found to maintain >95.0% of its initial concentration after storage at 25.0°C for 34 days in sodium lactate, 0.9% in sodium chloride, and 5% and 10% in glucose solutions. Linezolid was degraded at alkaline pH values by first-order kinetics. Activation energy data showed that temperature, but not ionic strength, influenced the degradation rate significantly. An activation energy of 58.22 kJ/mol was determined for linezolid in 0.1 M sodium hydroxide solution. Linezolid was least stable at high pH values and at elevated temperatures. It was determined that linezolid has adequate stability for the preparation of intravenous fluids for clinical administration. Conclusion Linezolid was found to have a shelf life of 34 days at 25°C when added to sodium lactate, 0.9% sodium chloride, and 5% and 10% glucose solutions. It was least stable at high pH values and at elevated temperatures.