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 Guideline on NHSGGC StaffNet for more detail). It is important to note that specialist medicines are often not included in a patient's Emergency Care Summary or GP print out (e.g. darbepoeitin, methotrexate, depot antipsychotic 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.
Considering the principles above, it should be remembered that each individual patient and their circumstances will differ. Generalised advice for selected medicines or groups of medicines follows, but this advice 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.
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 anticoagulants, 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.
Missed clozapine doses can result in relapse of psychotic illness and should be avoided. Establish how long since patient's last dose and seek senior advice / pharmacy advice if more than 48 hours have elapsed. It should be noted that acute hospital sites do not routinely stock clozapine. Ensure supply is transferred with patient between wards / hospitals to avoid a break in treatment. For more information see PostScript Acute 6 (May 2012) on GGC Medicines Website
Always check for drug interactions with all existing therapy and when prescribing new medicines. Check BNF Appendix 1 for common interactions (for general antibiotic interactions, see Antibiotic Allergy and Interactions) and information on QT interval prolongation 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.
Oral 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.
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.
For transplant patients, discuss with consultant before deciding to withhold immunosuppressants.
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.
Important issues to consider before prescribing - See Management of Drug Misusers in Hospital
Missed / delayed doses of pyridostigmine can have serious adverse events and must be avoided; if nil-by-mouth consider nasogastric administration or parenteral neostigmine (seek pharmacy / neurology advice). Some medicines may worsen myasthenia and should be avoided e.g. gentamicin (search for 'Medicines that may affect patients with myasthenia gravis' on StaffNet). Do not alter immunosuppressants (seek advice).
Nephrotoxic drugs (e.g. non-steroidal anti-inflammatory drugs (NSAIDs), angiotensin converting enzyme inhibitors) should be withheld in patients presenting with an acute kidney injury. Consider restarting if renal function improves. Permanent discontinuation or a dose adjustment may be required depending on the individual circumstances. Seek renal advice if unsure.
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 management of nil-by-mouth patients and how to obtain a supply out of hours.
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 enterally (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).
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, see Management of Depression for information on citalopram. Further information on drugs and QT interval prolongation can be found in PostScript Extra 21 (GGC Medicines Website) and www.crediblemeds.org