Covert administration of medicines: pharmaceutical issues

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A summary of the pharmaceutical issues to consider and reference sources available to help pharmacists provide advice on covert administration of medicines.

Ensure you are familiar with the legal issues and frameworks surrounding covert administration of medicines:

Seek pharmacist advice

National Institute for Health and Care Excellence (NICE) guidance on covert administration of medicines to adults receiving social care in the community recommends seeking advice from a pharmacist to plan how medicines will be given.

To provide advice, the pharmacist will need to consider the pharmaceutical issues with covert administration, particularly the risks and patient factors.

These are summarised in this article and we also provide links to useful reference sources for further detail.

Risks and factors to consider

Very often, there is no information available on the stability of medicines when mixed with food or drink. However, it is useful to consider the risks of the medicine degrading in food or drink versus the risks of not giving the medicine at all.

When adding a medicine to food, try and add it to the first mouthful of food, so that the full dose is received.

At all times healthcare professionals should ensure that any increased risk of harm from manipulating a medicine is minimised, and that the action is justifiable in terms of the potential clinical benefits to the patient.


You will need to consider the taste and other possible effects of the medicine, particularly if tablets are to be crushed or contents removed from capsules.

For example, crushed sertraline tablets can be mixed with soft food or drink for administration (off-label), but they have a bitter taste. They may also have a slight anaesthetic (numbing) effect on the tongue.

This means you will need to consider the best way to hide the taste, such as using something more strongly-flavoured like juice, yoghurt or jam. Check individual likes and dislikes with family or carers to decide what might be suitable.

Because of the possible numbing effect, take care with giving the patient hot food or drinks with, or immediately after, giving crushed sertraline tablets.

If problematic, you may need to consider alternatives as outlined in our article: Selective serotonin reuptake inhibitor (SSRI) formulations suggested for adults with swallowing difficulties.

Absorption with food

Food can affect the absorption of medicines in different ways. It can affect the rate (speeding up or slowing down) of absorption of medicines, as well as the amount  (increasing or reducing) of medicine absorbed.

To help with deciding whether or not to give medicines covertly you should consider the effects of food on medicines.

You will often find information about this in the relevant Summary of Product Characteristics (usually available on the emc or MHRA Products website). Alternatively, the Patient Information Leaflet (PIL) may give instructions about taking the medicine with food or on an empty stomach.

Individual monographs in the BNF advise on any cautionary labels that need to be applied to dispensed medicines with respect to administration with food or on an empty stomach (before food).

For example, for the antibiotic flucloxacillin, the BNF recommends applying cautionary label 23: “Take this medicine when your stomach is empty. This means an hour before food or 2 hours after food”. This is because food reduces absorption of flucloxacillin. Mixing it with food to give to a patient covertly may result in the antibiotic not working. Other options will need to be discussed with the prescriber.

Incompatibility with foods or drinks

Some medicines may be pharmaceutically incompatible with certain minerals (or salts) in food or drinks, such as calcium, iron, magnesium, aluminium and zinc. Similarly to the absorption issues discussed above, this may help in deciding whether or not to give a medicine covertly.

For example, the antibiotic ciprofloxacin reacts with these minerals. It binds with the minerals to form an insoluble complex known as a “chelate”. This results in reduced absorption of ciprofloxacin, so it would not be suitable for mixing with foods or drinks containing these minerals.


For some medicines, crushing tablets or opening capsules may be a potential health risk to the person giving them (the carer) if they are exposed to the powder or dust created, either by contact with their skin, mouth or eyes, or by breathing it in.

Examples of tablets or capsules that may not be safe to crush or open include medicines that are:

  • irritant
  • cytotoxic
  • immune-suppressing
  • teratogenic
  • hormonal
  • steroids

Enteric coating or extended-release formulations

Crushing or chewing tablets or opening capsules with enteric coating or extended-release (also known as modified-release or prolonged-release) properties can affect their release characteristics. The medicine may be released earlier than usual, or in larger amounts, or in a different part of the digestive system (e.g. in the stomach instead of the intestine).

This puts the patient at risk of harm, either from side effects or toxicity of the medicine, or from the medicine not working as it should do.

There are some exceptions, but usually manipulation of enteric coated or extended-release medicines is not recommended.

Reference sources and how to use them

A variety of reference sources are available to help pharmacists and other healthcare professionals consider the pharmaceutical issues and patient factors when making a best interests decision to give medicines covertly.

Most of these don’t specifically consider covert administration of medicines. Instead they tend to focus on options for giving medicines to people with swallowing difficulties, including those who need medicines to be given via an enteral feeding tube, or to children.

Nonetheless this information can be extrapolated to the scenario of covert administration to decide whether it is safe to manipulate medicines (crush tablets or open capsules, and/or hiding medicines in food or drink), or whether there may be preferable alternatives.

Swallowing difficulties

All our advice on using medicines safely and effectively in patients with swallowing difficulties.

Update history

  1. Title and URL shortened.
  1. Reference to Colchester Hospital guideline removed as no longer available.
  1. Minor amendments to 'Risks and factors to consider: Acceptability' section made following user feedback.
  1. Article published by Samantha Owen, Southampton Medicines Advice Service.
  2. Published

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