Objective: To investigate pharmacistsʼ interpretation of instructions in package inserts of prescription drugs related to pregnancy and lactation in order to identify potential problems or differences in understanding regarding recommended usage.

Methods: Questionnaires were sent to the following types of pharmacists: (i) Japanese Society of Hospital Pharmacistsʼ Board Certified Pharmacists in Pharmacotherapy during Pregnancy and Lactation as well as Board Certified Pharmacy Specialists in Pharmacotherapy during Pregnancy and Lactation (collectively, JSHP-certified pharmacists), (ii) pharmacists providing outpatient consultations regarding pregnancy and drugs at regional core hospitals affiliated with the Japan Drug Information Institute in Pregnancy (core hospital pharmacists), and (iii) pharmacists without any specialty training (general pharmacists).

Results: Complete responses were obtained from 91 of 182 JSHP-certified specialists (50%), 81 of 226 core hospital pharmacists (35.8%), and 400 general pharmacists. Most JSHP-certified pharmacists and core hospital pharmacists indicated that the use of medications contraindicated during pregnancy could be considered on an as-needed basis (83.5% and 85.2%, respectively). The majority of general pharmacists answered that pregnant women should not receive such drugs (55.0%). For drugs that are recommended in pregnancy only if treatment benefits outweigh the risks, the majority of the JSHP-certified, core hospital, and general pharmacists responded that their use could be considered on an as-needed basis (74.7%, 71.6%, and 50.5%, respectively).

Conclusion: Our study suggest that pharmacistsʼ professional background and training influence the interpretation of drug package insert instructions. Inclusion of more detailed clinical data is desirable to ensure a consistent understanding of package insert recommendations among different types of pharmacists.