Assessing Medicines on Admission in Acute Patients

Introduction

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 NHSAAA Code of Practice for Medicines Governance Policy: Prescribing on Admission to Hospital on AthenA for more detail - link only active if accessing via NHS network). 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.

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. When starting any new medicines check for interactions with anticoagulants.

Clozapine:

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

Diabetes:

Always carefully check the type of insulin, dose and frequency of administration. ECS will not 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)). 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.

Drug interactions:

Always check for drug interactions with all existing therapy and when prescribing new medicines. Check BNF Appendix 1 for common interactions. 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 haematology or oncology. 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 below for further advice.

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

HIV / Hepatitis C medication:

Ensure multiple missed doses of HIV / Hepatitis C treatment are avoided as this can adversely affect treatment outcomes and risk development of resistance. 

Long-term corticosteroids:

When infection is present, to prevent adrenal insufficiency consider doubling the steroid dose. 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.

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 the Drug-induced QT Prolongation guideline. Information can also be found on www.crediblemeds.org (login 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.