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A review of laboratory results across New Zealand for therapeutic drug monitoring (TDM) of infliximab and adalimumab concentrations and antidrug antibodies (ADAs) over 4 years was completed. Of 6591 results, the median serum concentration for infliximab was 5.7 mg/L and for adalimumab was 5.5 mg/L. Subtherapeutic drug concentrations (<7 mg/L) were measured in 54% of samples. Drug concentrations <2 mg/L were measured in 23% of samples, with ADAs detected in 51% of these. The high number of samples with subtherapeutic drug concentrations and common ADA detection is consistent with failing therapy but could also suggest that standard dosing is frequently too low for patients. These results reinforce the value of antitumour necrosis factor drug TDM in making decisions to adjust dosing or switch agents in patients taking infliximab and adalimumab., (© 2023 Royal Australasian College of Physicians.)

Background: New Zealand went into lockdown March 2020 successfully eliminating the circulation of the coronavirus disease 2019 (COVID-19) virus. During lockdown there were reduced rates of respiratory infections and hospital admission numbers were low. At the time, rumours of benefit and harm of medicines for COVID-19 were widespread in the lay and medical media., Aim: To describe changes in inpatient prescribing in an acute general medicine service during the New Zealand COVID-19 lockdown in 2020., Methods: Rates of prescribing of medicines during the 33 days of lockdown were compared with a 33-day control period before lockdown. Prescriptions, patients and bed days were calculated from the hospital patient administration and electronic prescribing and administration systems., Results: In the general medicine service, acute admissions were 20% lower during lockdown (from 1216 pre-lockdown to 974). There was a small decrease in the rate of prescriptions per patient (10.1 vs 10.4, P = 0.01) during lockdown, and the average length of stay was shorter (3.2 vs 3.6 days). Nebulised administration decreased by 75% (1.3% vs 5.3% of admissions) but unexpectedly there was no change in the prescribing rates of antibacterial medicines, e.g. amoxicillin (26% vs 26%). There were no changes in rates of prescribing of medicines being rumoured to potentially improve (e.g. hydroxychloroquine) or worsen (e.g. angiotensin-converting enzyme inhibitors) COVID-19 outcomes., Conclusions: Acute medical admissions decreased 20% during lockdown for COVID-19, with a proportional decrease in prescriptions. Reduced rates of respiratory tract infections did not lead to decreased prescribing of antibacterial medicines. Rumour-based prescribing did not eventuate., (© 2022 The Authors. Internal Medicine Journal published by John Wiley & Sons Australia, Ltd on behalf of Royal Australasian College of Physicians.)

Background: Routine therapeutic drug monitoring (TDM) during treatment with anti-tumour necrosis factor (anti-TNF) agents in inflammatory bowel disease may increase treatment efficacy and cost-effectiveness, and reduce the risk of loss of response., Aims: To assess the current use of anti-TNF agent TDM, including trough concentration and anti-drug antibodies, among gastroenterology practitioners in New Zealand., Methods: A web-based survey was delivered to gastroenterologists and advanced trainees in New Zealand, identified by the New Zealand Society of Gastroenterology., Results: The response rate was 36% (48/134). Adalimumab was the most common initial anti-TNF agent used (78%, infliximab 22%). Ninety-three percent of those who completed the survey used TDM, mainly in cases of non-response or loss or response. Most respondents (93% and 83% for adalimumab and infliximab, respectively) measured trough concentrations within 24 h prior to the next administration. In patients in clinical remission but with endoscopic inflammation on anti-TNF agents, 72% would measure drug concentrations. In the presence of anti-drug antibodies, 45% would add an immunomodulator in patients with active disease and 47% would add an immunomodulator in patients in remission. With low trough concentrations, 77% would make no changes if the patient was in remission, and 75% would increase the dose in case of active disease., Conclusion: TDM was routinely used among inflammatory bowel disease gastroenterology clinicians who responded to this survey. However, interpretation of results and decision-making is variable, suggesting more guidance is required., (© 2020 Royal Australasian College of Physicians.)

Background: An electronic prescribing and administration (ePA) system has been progressively rolled out to Canterbury District Health Board (CDHB, Christchurch, New Zealand) public hospitals since 2014, and is currently used for around 1300 tertiary beds. ePA data can be used to monitor user behaviour, and to evaluate and inform the local customisation of clinical decision support (CDS) tools within the ePA system., Aims: To describe retrospectively illustrative vignettes of CDHB ePA analyses that have been used for CDS., Methods: Alerts were developed according to a set of common principles agreed upon by the CDHB CDS Working Group. Alerts were informed and evaluated by extracting and parsing data for various time periods during 2016 to 2018 from the CDHB ePA database., Results: There was a median of 74 000 prescriptions a month. After examining 525 spironolactone prescriptions, the high dose alert threshold was set at 100 mg with an expected alert burden of 3%. The presence of a ceftriaxone shortage prescribing alert for 1 week was associated with a prescribing rate that was lower than 95% of the preceding 52 weeks. Following review of 367 fentanyl patch alerts, revision of the alert led to false positives falling from 43% to 3% (P < 0.0001). At the point of firing, 6% of antithrombotic drug interactions alerts led to immediate changes in prescriptions (94% overridden), and a further 22% were changed within 30 min after the alert., Conclusions: Local data extracts from ePA systems can inform iterative configuration of the software and monitor user behaviour., (© 2019 Royal Australasian College of Physicians.)