By Sarah Cullivan

Dietary restrictions that exclude animal content are common and complex. While it is generally acknowledged and accepted that most medications are tested on animals prior to the introduction in human subjects to ensure safety, it is not always clear to prescribing physicians and consuming patients which medications and medical products are animal derived or contain animal content. Therefore physicians may unintentionally prescribe these medications and goods to patients who typically exclude animal content from their diet and this can have implications for patient autonomy, trust and treatment compliance (1). Furthermore it is difficult to predict what is tolerable to patients with dietary restrictions as this is a heterogenous group, with different principles and degrees of adherence. Is it acceptable to use these products if there is no equivalent alternative? Is it tolerable if the product is not ingested but delivered via an alternative route such as gelatin containing hydrocolloid wound dressings or surgical mesh? Or is this pandoras box of unanswerable questions as there is too much product and patient variability and should we paternalistically ‘spare’ patients the burden of these difficult questions and choices.

It is estimated that there are approximately 1.5 billion vegetarians worldwide. (2) While diets that exclude animal content can vary dramatically in specifics, motives and general compliance, some of these dietary restrictions have strong religious foundations, such as the Halal and Kosher diets, both of which exclude porcine product consumption. Additionally it is often quoted that individuals who exclude animal content from their diets are doing it for ‘lifestyle reasons’, as a means to delegitimize their decision; however lifestyle decisions frequently encompass ethical, environmental and medical motives. Evidence suggests that transitioning towards more plant-based diets could reduce food-related greenhouse gas emissions, global mortality and save anywhere between 0.4-13% of global gross domestic dollars (3). Therefore if there are potential sustainability, health and monetary gains to plant-based diet lifestyles, it seems reasonable that physicians should be able to readily identify which medications contain animal products? Well actually perhaps not.

A small survey of non-consultant hospital doctors in an Irish Hospital performed in June 2020 regarding their knowledge of animal content in prescribed medicines and goods demonstrated that these physicians accurately identified products with animal content 55% of the time, with an accuracy ranging from 14 to 91%.  Despite this suboptimal knowledge and the fact that most physicians don’t ask patients regarding dietary restrictions as part of their routine consultation, most of these doctors (73%, n=16) would chose an equivalent alternative without animal content if readily available. Unfortunately in Ireland it is difficult to find a comprehensive list to guide physicians regarding alternative choices without animal content, which is an additional barrier to change. Some authorities, such as Queensland Health Medication Services, have compiled a list of medications of animal origin to assist physicians with queries, with the caveat that keeping such a list accurate and current is difficult (4). Furthermore, one could effectively argue that physicians are already stretched at present with current staff shortages, unsociable working hours and pandemics to fight and that the animal content of medication might not be at the top of the long list of required change projects. But who is responsible then? Is the onus on the consumer with specific requirements to source the information themselves? But where can they go to seek reliable information? It might be more productive to divert our attention to the manufacturers and legislators who are responsible for much of the ambiguity around what should be a simple issue.

While manufacturers are required to provide a list of active ingredients and excipients for medications, it is not always clear if these are from plant-based or animal sources. For example lactose is a common excipient in medications and while it can be sourced using vegetarian methods, it is traditionally extracted using bovine rennet, which is derived from the lining of the stomachs of slaughtered calves and therefore not suitable for vegetarians (5). Increased transparency during the manufacturing process and improved product labelling would assist consumers, pharmacists and physicians.

The animal content in active and inactive ingredients in medical products is frequently avoidable. Improved transparency in the manufacturing process, product labelling and physician awareness could limit unnecessary animal constituents.  These measures would respect patient autonomy, facilitate informed decision making and potentially cobenefit the environment and promote sustainable medical practices. National governments should address this issue as a matter of urgency as part of a comprehensive movement to maintain and sustain planetary and human wellbeing.

Author: Sarah Cullivan

Affiliations: Mater Misericordiae Universtiy Hospital, Dublin, Ireland

Competing interests: None to declare