Identifying Off‐Label Prescriptions Through Data Mining in Danish Community Pharmacy Servers: An Exploratory Study on Desmopressin, Diclofenac, Fucidin, Mirtazapine and Quetiapine

Abstract

The term off-label use describes the prescription and administration of medicines outside of the terms for which it officially has been approved, including age, dose and indication. Off-label data can be generated from the Danish National Prescription Registry through combinations with diagnoses; however, the community pharmacy servers provide equal, local, albeit less data through a faster and less constrained collection process. The data collection for this exploratory study took place at five community pharmacies in Denmark. Five drugs were chosen for the investigation and collection of prescription data across a 2-year period. Off-label use by age was observed to be 1.9% for diclofenac, 1.7% for desmopressin and 2.3% for quetiapine. The percentages were based on total number of 3881, 925, 2712 prescriptions, respectively. Off-label monitored by dosage appeared to be 75% for quetiapine; by box label text analysis, off-label indication was found to be 10-15% and 15-23% for quetiapine and mirtazapine (from a total number of 3178 prescriptions), respectively. By route of administration where fucidin ointment was applied to the nose in 60 patients, 83% were prescribed off-label (non-dermatological). This exploratory study revealed that pharmacy servers represent a reliable and up-to-date source to collect a substantial amount of raw prescription data. The method gives straightforward and simple access to analysis of off-label use by age and dose, whereas it is possible but difficult to interpret off-label indications and route of administration from the box label text.

Treatment indications and potential off‐label use of antidepressants among older adults: A population‐based descriptive study in Denmark

“…Although a few studies had exclusively focused on indication or off‐label use of antidepressants, they only included either pregnant women 23 or populations aged <18 years 14 or only included a single antidepressant (Mirtazapine). 24 A recent Danish study focusing on indications of redeemed antidepressants by pregnant women in 2006–2016 reported a lower proportion of missing and unspecified indications (21% combined) than our study. 23 Compared with pregnant women, older adults are likely to have diverse psychiatric/somatic conditions requiring treatment with antidepressants, 25 , 26 which may lead to a higher proportion of missing/unspecified indications.…”

“…Existing studies on antidepressants prescriptions in Denmark, in general, focused on drug utilization patterns. Although a few studies had exclusively focused on indication or off‐label use of antidepressants, they only included either pregnant women 23 or populations aged <18 years 14 or only included a single antidepressant (Mirtazapine) 24 . A recent Danish study focusing on indications of redeemed antidepressants by pregnant women in 2006–2016 reported a lower proportion of missing and unspecified indications (21% combined) than our study 23 .…”

Application of natural language processing techniques to identify off-label drug usage from various online health communities

“…There are other ways to estimate off-label use of medications. Andrulyte and Bjerrum 38 identified off-label prescriptions through data mining of pharmacy servers. However, this method lacks an easy way to identify off-label use by indication.…”

Effects of the antipsychotic quetiapine on sleep and breathing: a review of clinical findings and potential mechanisms

“…Daily doses of quetiapine for its approved indications range between 150 and 800 mg/day (AstraZeneca, 2020; FDA, 2020) following a 4–8 day low‐dose run‐in titration period (Brett, 2015; Drug Utilisation Sub‐Committee, 2013; Lee, Pilgrim et al, 2018). Yet, consistent with off‐label prescribing, >50% of quetiapine prescriptions are for doses of ≤100 mg (Andrulyte & Bjerrum, 2018; Carton et al, 2015; ClinCalc.com, 2023; Gjerden et al, 2017).…”