Pharmacoepidemiology, Volume 3, Issue 2 (June 2024) – 3 articles

Background: The paediatric use of ophthalmic chloramphenicol in New Zealand (NZ) is relatively high; however, little more is known about its utilisation, including whether this is equitable. This study aimed to describe chloramphenicol utilisation in NZ children aged five years and under, by patient ethnicity, socioeconomic deprivation, and urban/non-urban domicile. Methods: This analysis included every publicly subsidised chloramphenicol dispensing received from birth to five years of age, for every child born in NZ in 2013. Cumulative proportion of first exposure, dispensing rate per person-year, and seasonality of dispensing were quantified. These were calculated following stratification by ethnicity, socioeconomic deprivation quintile, and urban/non-urban health district. For cumulative proportion of first exposure, odds ratios (OR) were calculated and multivariate logistic regression was performed. For dispensing rate, incidence rate ratios (IRR) were calculated and zero-inflated Poisson regression was performed. Results: Almost one-quarter of NZ children received their first dispensing within the first year of life. By five years of age, 55.2% of children had received their first dispensing. By five years of age, children of Pacific ethnicity, those in the highest deprivation quintile, and in those non-urban health districts had lower odds of receiving chloramphenicol (adjusted OR 0.90, 0.79, and 0.81, respectively, all p < 0.001). In contrast, children of Māori ethnicity had higher odds (adjusted OR 1.99, p < 0.001). Māori and Pacific ethnicity, and residence in non-urban health districts, were associated with fewer dispensings (adjusted IRR 0.88, 0.75 and 0.87, all p < 0.001). In contrast, deprivation quintile was not significantly associated with dispensing rate. Conclusion: Chloramphenicol utilisation is prevalent among NZ children, and utilisation may be lower among children of Pacific ethnicity and those in non-urban areas Full article

Adverse drug reactions (ADRs) are frequent and represent a significant healthcare burden. ADRs are a potentially avoidable contributor to excess unscheduled hospital admissions, higher morbidity, mortality, and healthcare costs. The objective of this review is to examine the epidemiology of ADRs in older multimorbid adults and to explore strategies for ADR prevention. ADRs in this population are often linked to commonly prescribed medications, including anticoagulants, antiplatelet agents, insulin, and non-steroidal anti-inflammatory drugs, but ADRs and adverse drug events (ADEs) in fact encompass a much broader range of culprit drugs. Age-related factors such as changes in pharmacokinetics and pharmacodynamics, multimorbidity, polypharmacy, and frailty have been associated with ADR occurrences. Various strategies have been proposed to prevent ADRs in different clinical settings, such as structured routine medication review and the use of bespoke software applications to identify potentially inappropriate prescriptions and drug interactions. Although these approaches have demonstrated some improvement in the quality of prescribing, there is still a lack of consistent evidence regarding their effectiveness in preventing ADRs. The nuanced and often intricate complexities associated with older patients’ pharmacotherapy necessitate a comprehensive approach to attenuate the impact of ADRs within this growing section of most populations globally. Full article

Buprenorphine is a safe and effective medication to treat opioid use disorder (OUD) in pregnant patients and is intended to be continued throughout pregnancy, delivery, and at least the one-year postpartum period. However, delivery often involves the need for acute pain management with opioid medications, such as after a cesarean section. For patients receiving buprenorphine, the provision of prescription opioids may negatively impact OUD treatment outcomes; however, not optimally managing acute pain may also impede OUD treatment benefit. Evidence is needed to disentangle the impacts of opioid prescription provision and methods of pain management in the immediate postpartum period on OUD treatment trajectories, ultimately to inform clinical guidelines tailored to the unique needs of pregnant and postpartum people receiving buprenorphine. Accordingly, this study took an initial step towards this goal to conduct a secondary analysis of a retrospective cohort of pregnant patients taking buprenorphine for OUD at the time of delivery (n = 142) to determine whether receipt of an opioid prescription at birth hospitalization discharge was associated with the time of buprenorphine discontinuation within the 12 months following delivery. Among the sample, 26% (n = 37) were prescribed an opioid at the time of birth hospitalization discharge. The number of weeks post-delivery until buprenorphine discontinuation occurred was shorter amongst patients who were prescribed an opioid (median 11 weeks) compared to patients who were not prescribed an opioid (median 39 weeks; p < 0.001 by Mann–Whitney U test). However, a Cox regression model reported that receipt of an opioid prescription following delivery did not significantly increase the hazard ratio for buprenorphine discontinuation. In other words, OUD patients not prescribed an opioid at birth hospitalization discharge continued their buprenorphine for a longer median duration after delivery compared to their counterparts who received prescription opioids; yet, this finding did not reach statistical significance when taking into account additional clinical variables. The findings indicate how further research is warranted to inform evidence-based post-delivery pain practices for postpartum OUD treatment patients. Full article