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The right choice for your patient
Selecting the right medicines for patients with enteral feeding tubes requires careful consideration of clinical need, formulation, pharmacology, tube type and placement, and practical administration issues.
Decisions should be made on an individual patient basis, in partnership with patients and carers.
This stepwise process is designed to support you make safe and effective choices for enteral tube administration. Use this as a practical guide through each stage of decision making.
You should identify and understand the type of enteral feeding tube the patient has in place. The enteral tube size, material, and termination site can significantly influence medicine absorption and efficacy.
Refer to our article Knowing the types of enteral tube for further details.
Consider the need for each medicine, its site of action, and its pharmacokinetics, including absorption and metabolism.
These factors help determine if a medicine is still required, as well as if it will be effective, inactive, or potentially harmful when delivered to a specific part of the gastrointestinal tract.
Assess necessity and simplify regimen
Where possible,
- stop unnecessary medicines
- choose medicines which are taken once daily
- consider non-oral formulations such as transdermal patches or suppositories
Understand site of action and pharmacokinetics
You can check section 5.2 of the Summary of Product Characteristics (SmPC) for information on a medicine’s site of action and pharmacokinetics.
Acid-activated medicines
May lose their effectiveness if delivered somewhere other than the stomach, such as aspirin and enalapril.
Use an alternative treatment option if these medicines are administered via an enteral tube ending in the duodenum or jejunum.
If no suitable alternative is available, additional monitoring and dose titration may be required.
Stomach acting medicines
Some medicines work only in the stomach and should only be given through enteral tubes that end in the stomach.
For example, antacids should be avoided in patients with tubes that end in the duodenum or jejunum.
Stomach absorbed medicines
Some medicines are absorbed mainly in the stomach and lose effectiveness if given via an enteral tube that ends in the duodenum or jejunum. Examples include digoxin and phenytoin.
Use an alternative treatment option if these medicines are administered via an enteral tube ending in the duodenum or jejunum. If no suitable alternative is available, additional monitoring and dose titration may be required.
Medicines with extensive first-pass metabolism
Medicines with extensive first-pass metabolisms, such as opioids, tricyclics, beta blockers, or nitrates, may have increased bioavailability when delivered directly into the jejunum.
Use an alternative treatment option if these medicines are administered via an enteral tube ending in the duodenum or jejunum. If no suitable alternative is available, additional monitoring and dose titration may be required.
Monitor outcomes and provide clear instructions
Monitor efficacy when changing a patient’s medicine, dose frequency or formulation.
Provide written and verbal medicine administration and monitoring instructions, especially when patients move between care settings.
When choosing between available medicines, use a licensed medicine where available. Some medicines are licensed for administration via enteral tubes, this will be stated in the SmPC.
Summaries of Product Characteristics
SmPCs are available via electronic Medicines Compendium (eMC) and MHRA.
The licensing of the product for enteral tube administration would be outlined in section 4.2 and 6.6. Section 4.2 covers method of administration. Section 6.6 covers special handling of the medicines, such as reconstitution, dilution and administration via enteral tubes.
Licensing and instructions may differ between brands of the same medicine.
If a medicine is not licensed for enteral tube use, information in the SmPC can guide whether the liquid, tablet, or capsule can be safely administered via the tube. In such cases, the use is considered ‘off-label’.
If a licensed medicine is unsuitable, an unlicensed ‘Special’ may be considered.
Using a licensed medicine ‘off-label’ is preferred to using an unlicensed ‘Specials’ medicine. Licensed medicines have been evaluated by the MHRA for safety, quality, and efficacy but unlicensed medicines have not.
If you use a licensed medicine ‘off-label’ or an unlicensed medicine, the prescriber has extra responsibilities.
A number of resources provide guidance on the use of off-label and unlicensed medicines via enteral feeding tubes.
SPS resources
Checking if tablets can be crushed or capsules opened suggest information resources and points to consider before crushing tablets or opening capsules. This resource focus on swallowing difficulties but also provide information on pharmaceutical and clinical factors for determining if tablets can be crushed or capsules opened.
Assessing injectables for enteral administration outlines the clinical considerations on the use of injectable formulations for enteral administration.
Such guidance does not indicate suitability for administration via an enteral feeding tube. Additional formulation considerations, including the risk of tube blockage, viscosity, and excipient content, must also be evaluated, as discussed in the subsequent step.
The NEWT Guideline
The NEWT Guideline (subscription required) provides information on medicines administration via enteral feeding tubes.
Where method of administration differs depending on whether the drug is delivered to the stomach or the jejunum, separate instructions are given.
The Handbook of Drug Administration via Enteral Feeding Tubes
The Handbook of drug administration via enteral feeding tubes (subscription required) provides information on crushing or dispersing tablets and opening capsules, listed by brand and generic preparations.
Where method of administration differs depending on whether the drug is delivered to the stomach or the jejunum, separate instructions are given.
Medicine manufacturers
Sometimes manufacturers will provide information on administering their medicines ‘off-label’ to patients with enteral tubes.
Manufacturer medical information contact details are in the BNF or eMC. They are not obliged to give information on ’off-label’ use.
Formulations to avoid
Some medicine formulations can block enteral tubes, even liquids. Be aware of:
- medicines that could form gels, such as isphagula husk
- medicines that contain large granules which may block small-bore tubes, such as omeprazole dispersible tablets
- liquid formulations with high viscosity which could lead to resistance to flushing, such as metronidazole oral suspension
- effervescent tablets which could lead to gas production in the enteral feeding tube or sediments, if not fully dispersed before administration
Formulations that may cause adverse effects
Many liquid preparations are extremely hyperosmolar or contain large amounts of sorbitol, increasing the risk of gastrointestinal intolerance, overhydration and hypernatremia.
Effervescent formulations
Use with caution in people on fluid restricted or low sodium diets.
Effervescent tablets may contain large amounts of sodium and often require a large volume of water to allow them to fully disperse. Using effervescent formulations may lead to problems such as overhydration or hypernatremia.
High osmolality
Dilute these medicines with 10 to 30 mL of water before administration to reduce side effects.
Liquid formulations with high osmolality (greater than 600mOsm/kg) are more likely to delay gastric emptying and cause abdominal symptoms. These include distension, pain, and diarrhoea, when administered directly into the jejunum.
Sorbitol
Avoid sorbitol containing agents when possible.
Sorbitol is often used as a sweetener or stabiliser. It can cause bloating, flatulence, cramping and diarrhoea, if administered directly into the jejunum.
Its side effects are cumulative and based on the total daily dose:
- daily doses from 10g may cause bloating and flatulence
- daily doses over 20g may act as a laxative, resulting in cramping and diarrhoea
Who will prepare and give the medicine
Consider who will prepare and give medication and other practicalities.
Skills and training
Before recommending a formulation, consider the patient or carer’s:
- manual dexterity; crushing tablets, opening capsules may be difficult for some people
- ability to follow instructions to give or take the medicine correctly
- ability to give the medicine consistently
Health and Safety
Crushing tablets or opening capsules may create dust, increasing the risk of drug inhalation or skin exposure. This is important for cytotoxic or teratogenic medicines, antibiotics, immunosuppressants and hormones. Carers should take precautions to reduce exposure, such as wearing gloves and dispersing tablets in oral syringes.
If patients or carers cannot crush tablets or open capsules safely, liquid medicines may be more appropriate.
Advising how to crush or disperse tablets and open capsules provides practical information on crushing and/or dispersing tablets and opening capsules.
Medicine storage and supply
Liquid medicines may need more storage space, and some must be kept in a fridge.
Some liquid medicines have a short shelf-life, requiring more frequent supplies.
Some unlicensed liquids need to be ordered far in advance, which can be difficult for some people to manage.
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