Hidden danger: maize starch excipient allergy

To the Editor: We read with interest the article by Lukose and colleagues1 published in the Medical Journal of Australia. It is laudable of the authors to raise the awareness of pharmaceutical excipients being a potential source of allergy as this is often overlooked. This is of particular clinical relevance in the current climate of frequent medicine shortages, which may necessitate brand substitution.2 In some cases, the Therapeutic Goods Administration (TGA) may provide special access to alternative overseas medicines in the absence of Australian registered products.3

We wish to highlight from our experience as medicines information pharmacists that obtaining pharmaceutical excipient data, particularly for overseas products, can be challenging and time consuming. Multiple resources are often required, which may not be feasible or readily available to other health professionals.

In practice, if a subscription to the Monthly Index of Medical Specialties (MIMS) is inaccessible, both the consumer medicines information and product information for most medicines are publicly available through the TGA Australian Register of Therapeutic Goods (ARTG) website. The ARTG Search Visualisation Tool4 allows users to filter by active ingredient and pharmaceutical excipients to identify brands that are suitable for patients with specific excipient allergies. Excipient information for medicines not registered for use in Australia, including those obtained through the Special Access Scheme,3 is not readily available through MIMS or the ARTG website. Lukose and colleagues referred to Pillbox, a United States National Library of Medicine5 database that includes data for excipients in American medicines. We acknowledge this database was used to highlight the proportion of marketed products containing maize starch; however, the resource was retired in January 2021.5 Despite the data remaining available, the database is no longer updated and is unsuitable for clinical use.

As highlighted by Lukose and colleagues, pharmacists are an invaluable resource for these enquiries. State or hospital‐based medicines information services can support prescribers, through access to a range of subscription resources and the ability to liaise directly with pharmaceutical suppliers, including for overseas products. The national Medicines Line (1300 MEDICINE) can also assist patients with these enquiries.

Again, we thank Lukose and colleagues for raising this important concern.