There are many instances where everyday drug instructions can look simple on a surface level but have the potential for deeper misunderstandings. This can have a direct impact on patient safety. This article focuses on six real examples from leaflets of approved medicines in English-speaking countries to do with dietary instructions and contraindications.

Example 1: Take on an Empty Stomach

This is a vague instruction and causes confusion about what “empty” means and when to take the medication. Users might think that they can take it right after waking up, too soon before or after eating. This can affect absorption or causing stomach irritation.

A solution could be to make it more specific: “Take one hour before eating or two hours after a meal. This is so that your body can absorb the medicine properly.”

Example 2: Take with Food

This instruction does not specify whether to take it with a full meal or a light snack. This can cause misunderstandings in the sense that patients might take it with inadequate food. This can lead to incomplete absorption or stomach upset.

A solution could be to provide examples that would need to be culturally appropriate to the target audience, as well as explaining it is important to take the medicine in this way: “Take with a meal or a large snack like a sandwich or a bowl of cereal. This is so that your body can absorb the medicine better.”

Example 3: Take with a glass of water

This does not specify the amount of water required. Is it a full glass? Half full? Less than that? It can be misunderstood because patients might drink too little or sip the water. This can have an impact on absorption or increasing the risk of choking.

A solution could be to specify the measurement, which would have to be localised according to the target audience: “Take each tablet with at least 240 ml of water (a full glass). This is to make sure that you swallow the tablet safely and that your body absorbs the medicine properly.”

Example 4: Avoid Dairy Products

This is deficient on a number of levels. The first is ‘avoid’. As a verb it is not useful in instructing you what to do. Are you supposed to make sure you are not in the vicinity of dairy products, and if you do ever encounter them, do you walk around them so that they cannot hurt you? It is better to turn the instruction into something more concrete and less open to interpretation (or mockery), such as ‘do not eat or drink dairy products’. Then, there is the omission of what dairy products are. Can we make a safe assumption that all laypeople, including people with low health literacy, understand what is a dairy product? What is the harm in providing two examples, one of a solid dairy product, one of a liquid one, like cheese and milk, respectively? Then, we come to the biggest deficiency of the instruction: it fails to explain why or for how long the user should not have dairy products for. As a consequence, users of the medicine might not have dairy unnecessarily or consume it too soon before or after dosing, which can affect how the body absorbs the medicine.

A solution could be: “Do not have dairy products like cheese or milk within 2 hours before or after taking this medication. This is because dairy can have an effect on how your body absorbs the medicine.”

Example 5: Avoid Grapefruit Juice

I will not revisit the ‘avoid’ issue, apart from repeating a simple mantra that a now retired mentor used to say: ‘avoid using avoid’. The main issue with this instruction is that it does not explain why the user should not have grapefruit juice or how long they should not have it for. This could mean that patients might intentionally not drink grapefruit juice only at the time of dosing, not realising it can affect drug metabolism for hours afterwards.

A solution could be as follows: “Do not drink grapefruit juice while taking this medication, as it can change how the medicine works in your body. Do not drink any grapefruit juice for at least 24 hours before and after taking the dose.”

Example 6: Avoid Alcohol

It does not specify whether to refrain from drinking all alcohol or just certain amounts, how long to abstain from it for or why. This can give rise to the understanding that patients might think a small amount is okay, or they might stop drinking alcohol only right after taking the medication.

One solution to clarify this could be: “Do not drink any alcohol, including beer, wine, or spirits, while taking this medication and for 48 hours after the last dose. Alcohol can make you feel more drowsy or dizzy.”

The seemingly simple instructions found on medication leaflets are often more complex than they appear. Ambiguities in phrases like “take on an empty stomach” or “avoid dairy products” can lead to misunderstandings that directly impact on patient safety and medication effectiveness. As this article demonstrates, clearer communication is not just about choosing simpler words; it is about providing context, examples, and reasons that make the instructions meaningful and actionable. By addressing these hidden complexities, we can improve patient understanding, enhance medication adherence, and ultimately support safer healthcare outcomes.

Thank you for reading!

Mark Gibson, Leeds, United Kingdom, March 2025