Enteral Feeding - Preventing Drug 
                               Nutrient Interactions UHL Guideline                                                                      Nutrition and Dietetic Service 
                                                                                                                                                                          
                                                                                                                                      Trust reference B62/2019  
                                                                                                                                                                          
                         
                        1. Introduction and Who Guideline applies to  
                        1.1         This guideline is for Dietitians to refer to, when reviewing patients on an enteral feed 
                                    and medications. It may also be useful of other members of the Multidisciplinary 
                                    Team (MDT).  
                        1.2         The purpose of this guideline is to highlight possible drug and enteral feed 
                                    interactions, advise when a break should be provided in an enteral feeding regimen 
                                    to allow effective drug administration and allow the MDT to work effectively together 
                                    to avoid drug nutrient interactions that may cause the medication to be ineffective. 
                        1.3         A drug nutrient interaction has been defined as one that causes a 20% change in the 
                                    pharmacodynamics or pharmacokinetics of the medication (Lingtak-Neander, 2013).  
                        1.4         It is the responsibility of the Dietitians along with other MDT members to highlight 
                                    these interactions. The Dietitian can then make appropriate adjustments to the 
                                    patients enteral feeding plan. 
                        1.5       There are 4 types of reactions: 
                              i)    Chemical interaction, binding the drug and reducing its absorption. 
                              ii)   Physical interaction between the drug formulation and the feed formulation, causing a 
                                    change in the feed consistency and potentially resulting in blockage of the feeding 
                                    tube. 
                              iii)  Interaction between the drug and a specific nutrient involved in the metabolism of 
                                    that drug which can cause loss of drug effect due to impaired absorption, increased 
                                    drug clearance or blocking of pharmacological action. 
                              iv)  Interaction with the feeding tube itself which can reduce plasma concentration of the 
                                    drug compared to oral administration. 
                        2. Guideline Standards and Procedures 
                        2.1         General  points  to  consider  when  a  patient  is  on  an  enteral  feed  and  requires 
                                    medications that may interact with it. 
                        2.2         Will Nurses be able to realistically implement the number of recommended breaks? 
                        2.3         Will the number of breaks limit your ability to meet the patient’s full nutritional needs? 
                        2.4         Will the number of breaks lead to higher feed rates and will that impact feed 
                                    tolerance? 
                        2.5         Liaise with pharmacy and medical team to review drug necessity (de-prescribe where 
                                    possible), medication preparations, administration routes, timings or correct 
                                    monitoring of the therapeutic effect. 
                        2.6         Drugs with enteric coating should not be crushed to go down a tube as the enteric 
                        coating is designed to protect the medication. Slow release drugs should not be crushed as 
                        these are intended to be released over a long period of time. Cytotoxic and hormone 
                        medications should not be crushed due to risk to the administrator. Please refer to policy  
                        Administration of Medicines to Adult Patients who cannot Swallow Solid Dosage Forms (e.g: 
                        Tablets or Capsules) Guidelines for Practice (B31/2008) for further guidance. 
                         
                        Enteral Feeding - Preventing Drug Nutrient Interactions UHL Guideline 
                        V2 approved by Policy and Guideline Committee on 20 March 2020   Trust ref: B62/2019                                                    Next Review: April 2023 
                              NB: Paper copies of this document may not be most recent version.  The definitive version is held on INsite Documents 
                         
                         
                        2.7         Ensure that nurses are flushing the feeding tubes adequately before, between and 
                                    after medications to minimise tube blocking. Please refer to Enteral Feeding Tube 
                                    Administration in Adults Policy and Procedures (B30/2019) 
                        2.8         Potential drug and enteral feed interactions will be documented on the enteral 
                                    feeding regimen, and in the dietetic medical note entry. Verbal handover will be given 
                                    to nursing staff and added to nerve centre where appropriate. Long term plans are to 
                                    include a flagging system on eMeds. 
                         
                        2.8         Table one contains a list of possible drugs that may interact with enteral feeds. This 
                                    list is not exhaustive and enteral feed and drug interactions should be considered if a 
                                    medication  is  not  providing  expected  results.  Liaise  with  Pharmacist  for  more 
                                    information. The information has been taken from 3 main sources and where there is 
                                    conflicting information, the longest break period has been recommended. 
                         
                        Table one. Medications that require an enteral feed break 
                        Name of                          Interaction                                 Administration                          Additional 
                        Medication                                                                                                           information and 
                                                                                                                                             action required 
                        Anti-retroviral                  Dolutegravir interacts                      Dolutegravir                             
                                                         with feed and                               Should be 
                        (HIV)                            medications containing                      administered 2 hours 
                        Dolutegravir                     polyvalent cations, such                    before or 6 hours after 
                        Elvitegravir                     as calcium, iron, zinc                      enteral feeds 
                        Raltegravir                      magnesium                                    
                                                         supplements.                                 
                                                                                                      
                                                         Elvitegravir and                             
                                                         Raltegravir interact with                   Elvitegravir and 
                                                         medications and feeds                       Raltegravir 
                                                         containing polyvalent                        
                                                         cations, such as calcium,  Should be separated 
                                                         iron, zinc magnesium                        by 4 hours from 
                                                         supplements.                                enteral feeds  
                                                          
                                                         . 
                                                          
                        Bisphosphonates                  Feed/food reduces                           2 hour break in                         Careful when 
                        :                                absorption                                  feeding before and 2                    crushing as drug 
                        Risedronate                                                                  hour break in feeding                   powder can cause 
                        Alendronic acid                                                              after administration of                 irritation 
                                                                                                     drug 
                        (osteoporosis)  
                         
                        Carbamazepine                    Interacts with enteral                      2 hour break in                         Medical team to 
                                                         feeding tube (polyvinyl                     feeding before and 2                    check bloods levels 
                        (seizures)                       tube) which in some                         hour break in feeding                   of the drug 
                                                         studies has been shown                      after administration of                 regularly. 
                                                         to reduce plasma                            drug if therapeutic                     If short term 
                                                         concentration of the drug                   levels of                               carbamazepine is 
                                                         when compared with oral  carbamazepine are                                          required a 
                                                         administration.                             not reached.                            suppository is 
                        Enteral Feeding - Preventing Drug Nutrient Interactions UHL Guideline 
                        V2 approved by Policy and Guideline Committee on 20 March 2020   Trust ref: B62/2019                                                    Next Review: April 2023 
                              NB: Paper copies of this document may not be most recent version.  The definitive version is held on INsite Documents 
                         
                         
                                                                                                                                           recommended. 
                                                                                                    Appropriate dilution of                Dietitians to raise 
                                                                                                    drug with sterile water                awareness of 
                                                                                                    to minimise the                        impact of starting or 
                                                                                                    interactions.                          stopping an enteral 
                                                                                                                                           feed may have on 
                                                                                                                                           carbamazepine 
                                                                                                                                           levels. 
                        Digoxin                         This is affected by high                    If patient requires a                  Ensure the medical 
                                                        fibre intake. Changes in                    fibre feed stop feed 2                 team are made 
                        (Atrial fibrillation)           enteral fibre content can                   hours before                           aware – blood 
                                                        have an effect on drug’s                    administration and for                 levels need to be 
                                                        narrow therapeutic                          1 hour afterwards. No                  checked regularly. 
                                                        window                                      break required in a                    Changing to a lower 
                                                                                                    non fibre containing                   fibre feed can could 
                                                                                                    feed.                                  cause a rise in the 
                                                                                                                                           therapeutic level 
                                                                                                                                            
                                                                                                                                            
                        Fluconazole                     Some reports indicate                       If feeding allows give                  
                                                        that enteral fluconazole                    a feeding break but if 
                        (Antifungal)                    interacts with feeds                        on continuous not 
                                                        particularly Jevity.                        necessary  to 
                                                                                                    compromise feeding 
                                                                                                    unless on Jevity in 
                                                                                                    which case the risk of 
                                                                                                    sub therapeutic 
                                                                                                    treatment should be 
                                                                                                    weighed against 
                                                                                                    benefits of feeding.   
                                                                                                     
                                                                                                    If withheld – 1hr 
                                                                                                    before and 1 hour 
                                                                                                    after 
                        Itraconazole                    Requires stomach pH to                      2 hour break in                         
                                                        be as acidic as possible                    feeding before and 2 
                        (Antifungal)                    for absorption.(NB - this                   hour break in feeding 
                                                        does not apply to                           after administration of 
                                                        commercial liquid                           drug.  
                                                        preparation)                                 
                        Levothroxine                    Interacts with calcium                      Usually prescribed in                  This is not time 
                                                        and iron in enteral feeds                   the morning at 06.00                   critical and will be 
                        (hypothyroidism)                and interacts with the                      therefore consider if                  applicable to 
                                                        feeding tube. Most likely                   need break 1 hour                      patients receiving 
                                                        to have reduced                             before and 1 after.                    feeds for more than 
                                                        therapeutic levels with                                                            5-7 days. Suggest 
                                                        jejunostomy feeds.                                                                 to medical team 
                                                                                                                                           that thyroid function 
                                                                                                                                           may require 
                                                                                                                                           monitoring in long 
                                                                                                                                           term patients on 
                                                                                                                                           enteral feeds. 
                                                                                                                                            
                        Enteral Feeding - Preventing Drug Nutrient Interactions UHL Guideline 
                        V2 approved by Policy and Guideline Committee on 20 March 2020   Trust ref: B62/2019                                                    Next Review: April 2023 
                              NB: Paper copies of this document may not be most recent version.  The definitive version is held on INsite Documents 
                         
                         
                        Penicillin                      The peak plasma levels                      2 hour break in                        No problems with 
                        Flucloxacillin                  of                                          feeding before and 1                   amoxicillin. 
                                                        phenoxymethylpenicillin                     hour break in feeding                  Penicillin and 
                        (antimicrobial)                 and flucloxacillin are                      after administration of                flucloxacillin are 
                                                        affected by the presence                    drug.                                  dosed QDS and so 
                                                        of food and therefore                                                              the number of 
                                                        best given on an empty                                                             breaks may be 
                                                        stomach. Amoxicillin is                                                            impractical. Speak 
                                                        unaffected.                                                                        with medical team 
                                                                                                                                           or pharmacist to 
                                                                                                                                           consider different 
                                                                                                                                           antibiotic or 
                                                                                                                                           different 
                                                                                                                                           preparation. 
                        Phenytoin                       Phenytoin reacts with the  2 hour break in                                         Not applicable if 
                                                        enteral feeding tube itself  feeding before and 2                                  prescribed 
                        (seizures)                      and the protein in the                      hour break in feeding                  intravenously (IV). 
                                                        feed. This reduces drug                     after administration of                 
                                                        absorption and                              phenytoin (oral or                     Discuss with 
                                                        consequent plasma                           enteral dose) is                       Pharmacist the 
                                                        concentration                               required.                              ability to reduce 
                                                                                                                                           frequency or alter 
                                                                                                                                           timings of 
                                                                                                                                           administration  
                                                                                                                                            
                                                                                                                                           NB – Caution - 
                                                                                                                                           despite using 
                                                                                                                                           feeding break there 
                                                                                                                                           have been reports 
                                                                                                                                           of unexpected low 
                                                                                                                                           phenytoin levels 
                        Quinolones:                     Bioavailability can be                      2 hour break in                        Advise medical 
                                                        decreased by up to 33                       feeding before and 2                   team to consider 
                        Ciprofloxacin                   with some quinolones                        hour break in feeding                  doses at the higher 
                        Levofloxacin                    when administered via                       after administration of                end of the dosage 
                        Ofloxacin                       jejunostomy and                             drug                                   range if on enteral 
                        Moxifloxacin                    absorption is reduced a                                                            feed and medical 
                                                        further 25% if                              Ensure Nurses are                      team to liaise with 
                        (antibiotics)                   administered with                           flushing feeding tube                  microbiology about 
                                                        continuous enteral feed                     thoroughly before and                  this. 
                                                        as it binds with ions in                    after drug 
                                                        the feed to produce                         administration.  
                                                        insoluble chelates. 
                        Rifampicin                      Interact with                               Rifampicin:                             
                        Isoniazid                       carbohydrate in enteral                     2 hour break in 
                                                        feed and reduce plasma                      feeding before and 1 
                        (Antibacterial)                 levels.                                     hour break in feeding 
                                                                                                    after administration. 
                                                                                                     
                                                                                                    Isoniazid:  
                                                                                                    1 hour break in 
                                                                                                    feeding before and 1 
                                                                                                    hour break in feeding 
                        Enteral Feeding - Preventing Drug Nutrient Interactions UHL Guideline 
                        V2 approved by Policy and Guideline Committee on 20 March 2020   Trust ref: B62/2019                                                    Next Review: April 2023 
                              NB: Paper copies of this document may not be most recent version.  The definitive version is held on INsite Documents