A 20-Year Analysis of Analgesic Enquiries to an Obstetric Medicines Information Service

Background: Access to reliable medicines information is essential to support safe medicine use during pregnancy and breastfeeding, where concerns regarding fetal and neonatal safety complicate clinical decision-making. Analgesics are widely used during these periods, yet uncertainty regarding safety persists due to evolving evidence, regulatory changes, and inconsistent information sources. Obstetric medicines information services play a critical role in addressing these information needs. This study aimed to evaluate patterns of analgesic-related enquiries to a pharmacist-led specialist obstetric medicines information service over a 20-year period. Methods: A retrospective observational study was conducted using enquiry data from the King Edward Memorial Hospital Obstetric Medicines Information Service (KEMH OMIS), Western Australia. All enquiries recorded between 1 January 2001 and 31 December 2020 were extracted from the Microsoft Access® database. Records with incomplete data were excluded. Data were standardised, coded, and analysed using Microsoft Excel® and SPSS® Version 25. Descriptive statistics were used to summarise enquiry characteristics, caller type, the timing of exposure, and analgesic medicines involved. Trends over time were analysed. Results: A total of 48,458 enquiries were analysed, of which 4,978 (10.3%) related to analgesics, making this the third most common medicine class. Most enquiries related to breastfeeding (62.1%), followed by pregnancy (32.7%). The public accounted for 60.9% of calls, while health professionals contributed 39.1%. The highest frequency of breastfeeding enquiries occurred within the first four weeks postpartum, and pregnancy enquiries were most common in the second trimester. Paracetamol was the most frequently enquired analgesic (24.5%), followed by codeine (19.8%), ibuprofen (14.4%), diclofenac (7.2%), and tramadol (9.3%). Analgesic-related enquiries declined significantly over time (p < 0.001), particularly codeine-related enquiries following regulatory safety warnings. Conclusions: Analgesics represent a substantial proportion of medicines information enquiries in pregnancy and breastfeeding, reflecting widespread use and ongoing safety concerns. Pharmacist-led medicines information services play a critical role in supporting safe analgesic use.