Assessing Medicines on Admission in Acute Patients


Reviewing a patient's current drug therapy on admission is important with decisions to be made by the prescriber as to whether to stop, withhold, amend, or continue any particular medicine as part of the medicines reconciliation process (see Good Prescribing Practice - General Advice and the NHSGGC Medicines Reconciliation Policy for more detail). It is important to note that specialist medicines are often not included in a patient's Emergency Care Summary (ECS) or GP print out (e.g. clozapine, darbepoeitin, methotrexate, antipsychotic depot injections, biologics) therefore, always use more than one source to verify medication history.

Below are general principles to consider and illustrative examples of issues for a select group of drugs.

General principles to consider for each medicine the patient is taking on admission

  • Ensure you know what the drug is and why the patient usually takes it
  • What impact will the medicines the patient is taking for other conditions have on the treatment for their presenting complaint? Think about interactions between individual medicines or even between medicines and conditions.
  • What will be the impact of withholding / stopping medicines on the patient's condition? Will it worsen the patient's pre-existing condition?
  • Do any medicines need amending on admission, either to better manage the condition that they have been admitted with or to reduce the risk of further harm?

Examples of situations using selected medicines

Considering the principles above, it should be remembered that each individual patient and their circumstances will differ. In view of this, the generalised advice for selected medicines or groups of medicines below needs to be considered alongside the patient's individual circumstances.

The following examples are not an exhaustive list of medicines where such considerations are required, but simply to illustrate the principles outlined above.

Antiplatelets and anticoagulants:

In most cases, you would not consider prescribing both an antiplatelet and an oral anticoagulant for a patient, unless on the advice of a specialist as this combination is associated with a significantly higher major haemorrhage complication rate than either agent alone. If a patient is admitted on warfarin, ensure the dose is clarified with a reliable source e.g. anticoagulation dosing letter (available via Clinical Portal) or the patient themselves. When starting any new medicines check for interactions with anticoagulants.


For advice on the management of patients on clozapine admitted to an acute hospital, see guidance here


Always carefully check the type of insulin, dose and frequency of administration particularly when importing from ECS to Clinical Portal. Clinical Portal/ECS are not likely to contain dose information and therefore confirming insulin dose and frequency with another source (e.g. patient or carer) is essential. Be aware of concentrated insulin pens (e.g. Toujeo 300 units/ml, Tresiba 200 units/ml, Humalog 200 units/ml) and combination pens (e.g. Xultophy (Tresiba 100 units/ml and liraglutide)). If patients on insulin pumps are admitted and unable to self-manage, remove pump and commence variable rate intravenous insulin infusion (VRIII). Always continue basal/long-acting insulin in a type 1 patient (even if fasting or nil-by-mouth), however dose may need adjustment.  In patients with type 2 diabetes, non-insulin therapies may need to be withheld or have their dose adjusted. See the GGC Guideline Diabetes inpatient Prescribing FAQs for Junior Doctors for further information and advice.

Drug interactions:

Always check for drug interactions with all existing therapy and when prescribing new medicines. Check the BNF (Athens login required) for common interactions. For general antibiotic interactions, see Antibiotic Allergy and Interactions and for information on QT interval prolongation see below. Contact your clinical pharmacist or Medicines Information (see Appendix 6 for contact details) if unsure how to manage an interaction or its potential significance.

Immunosuppressant and chemotherapy agents:

Anticancer medicines, including chemotherapy and biological modifiers, should be withheld in all circumstances until advice is sought from the on-call haematology or oncology registrar. Common toxicity from systemic anti-cancer treatment includes myelosuppression, vomiting, diarrhoea and mucositis though side effects are numerous and drug-specific. Patients who are receiving, or who have previously received,  immune checkpoint inhibitors (e.g. ipilimumab, pembrolizumab, nivolumab, avelumab, atezolizumab, cemiplimab and durvalumab) are at risk of immune-related adverse events.  See Immune-related adverse events for more information.

Contact local rheumatology department regarding patients on Disease Modifying Anti-Rheumatic Drugs (DMARDs) or biologics (see Management of Arthritis for list of agents) before deciding to withhold immunosuppressants unless infection is suspected, in which case withhold and discuss with the specialists. If patient is on long-term corticosteroids then see further below for advice.

For transplant patients, discuss with consultant before deciding to withhold immunosuppressants.

HIV/Hepatitis C medication:

Multiple missed doses of HIV/ Hepatitis C (HCV) treatment can adversely affect treatment outcomes and risk development of resistance. Contact the HIV pharmacy team or the HCV pharmacy team who can confirm treatment regimen as well as provide drug interaction advice, if needed. See HIV Infection In Hospital for further information.

Long-term corticosteroids:

When infection is present, to prevent adrenal insufficiency consider doubling the steroid dose. See Management of Adrenal Insufficiency for further advice. In certain circumstances, for example in severe / life-threatening gastrointestinal bleeding, it may be appropriate to consider temporarily withholding glucocorticoid therapy. Seek senior medical advice.


For important issues to consider before prescribing, see Management of Drug Misusers in Hospital.

Myasthenia Gravis:

For advice on the management of patients with myasthenia gravis admitted to acute hospitals, including if nil by mouth or infection present, see guidance here

Nephrotoxic drugs:

In patients with an acute kidney injury (AKI), consideration should be given to withholding medication which may exacerbate it (e.g. non-steroidal anti-inflammatory drugs, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, diuretics). Decisions should be made on an individual basis, bearing in mind that it may be appropriate to continue certain medications. If medication is withheld, consideration should be given to restarting if renal function improves. Permanent discontinuation or a dose adjustment may be required depending on the individual circumstances. Consider whether the patient is prescribed any other medication where the dose may need to be amended appropriate to the degree of renal impairment. Before prescribing any new medication, consider whether it may exacerbate AKI and/or whether dosage adjustment may be required (e.g. certain antibiotics or opioid analgesics). Seek senior advice if unsure. 

Parkinson's disease medicines:

Missed or significantly delayed doses can have serious adverse effects and must be avoided. An accurate history of the medicines, dose, timings and preparations should be taken. See Parkinson's Disease in Acute Care for general information on the management of patients with Parkinson's disease (including management of nil-by-mouth patients) and how to obtain a supply out of hours.

Patients who are either nil-by-mouth or have swallowing difficulties:

Follow the principles outlined above and ensure essential medicines are continued. This may require alternate routes / formulations so check suitability of alternative and dose equivalence. For instance, not all medicines can be given by enteral feeding tube (e.g. most modified release preparations), some may require dose adjustment if liquid preparations are used and some interact with enteral feeds. If unsure contact your clinical pharmacist / Medicines Information (see Appendix 6 for contact details).

QT interval prolonging medicines:

Be aware of the large number of drugs (and combination of drugs) which can prolong the QT interval. Some drugs can have a dose dependent effect, for example citalopram. Further information on drugs and QT interval prolongation can be found in Medicines Updates Extra (issue 08, July 2018) at Information can also be found on (log in required).

Sick Day Rules:

Dehydration can be a significant risk to patients taking certain medicines. The Sick Day Rules detail which medications should be stopped temporarily during illness which can result in dehydration (e.g. vomiting, diarrhoea and fever). Further information can be found on the Scottish Patient Safety Programme website. Medications which should be temporarily withheld include:

  • Diuretics (e.g. bendroflumethiazide or furosemide) which can contribute to dehydration.
  • Non-steroidal anti-inflammatory drugs, angiotensin converting enzyme inhibitors, angiotensin receptor blockers which can impair kidney function in a dehydrated patient.
  • Metformin where the risk of lactic acidosis is increased in dehydration.
  • SGLT2 inhibitors (e.g. dapagliflozin, empagliflozin or canagliflozin) which can worsen dehydration.


Guideline reviewed: October 2022

Page last updated: November 2022